Re: Are weekly z/VM IPLs necessary?
Mike, I clicked on the link and the website that appeared wanted your logon credentials :-). Harley -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Mike Walter Sent: Thursday, May 28, 2015 5:49 PM To: LINUX-390@VM.MARIST.EDU Subject: Re: Are weekly z/VM IPLs necessary? Enter the Wayback Machine for trip to 1996 by visiting: http://listserv.uark.edu/cgi-bin/wa?A2=ind9610L=IBMVMP=R10161=IBMVM9=AI=-3J=onX=D2B166CA66E8CA0104Y=Mike.Walter%40aon.comd=No+Match%3BMatch%3BMatchesz=4 (watch out for URL line breaks of that link). That post was written before Linux ran on any IBM mainframes, and it addresses some CMS application issues, but some parts (e.g. 'other systems', and accumulated changes affecting the next IPL) still apply. While you're there, search for other posts on that thread... interesting and enlightening reading. While z/VM can shutdown and restart at astonishingly speed (well under 10 minutes), large Linux servers can take much longer -- making the business case for more frequent IPLs a more difficult decision. But one must balance weekly IPLs against the potential for the extended recovery time which may (place your bets) be required to recover from those changes which have accumulated since the last IPL, and may detrimentally affect the next IPL. Provide your management with as many facts as you can find, and your advice, then let them make a decision -- that's why they get paid the big bucks, right? Mike Walter Aon Service Corporation The opinions expressed herein are mine alone, not necessarily those of my employer. -- In response to: -- Date:Wed, 27 May 2015 14:33:41 + From:Will, Chris cw...@bcbsm.commailto:cw...@bcbsm.com Subject: Are weekly z/VM IPLs necessary? We have gotten in the habit of IPLing our z/VM and zLinux guests every = Sunday during our standalone window. With the window shrinking and the = need for 24/7 availability is it really necessary to IPL every week? If = not what potential problems could we run into by not doing the IPL (memory = leaks, logs filling etc.). This is in comparison to the Intel side of the = shop (Red Hat, Windows) where they go months between IPLs. The only = benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and = is intended solely for the use of the individual(s) to whom this = communication is directed. If you are not the intended recipient, you are = hereby notified that any viewing, copying, disclosure or distribution of = this information is prohibited. Please notify the sender, by electronic = mail or telephone, of any unintended receipt and delete the original = message without making any copies. =20 Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are = nonprofit corporations and independent licensees of the Blue Cross and = Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ *** The information contained in this communication is confidential, is intended only for the use of the recipient named above, and may be legally privileged. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please resend this communication to the sender and delete the original message or any copy of it from your computer system. Thank You. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
On Thursday, 05/28/2015 at 06:50 EDT, Mike Walter mike.wal...@aon.com wrote: That post was written before Linux ran on any IBM mainframes, and it addresses some CMS application issues, but some parts (e.g. 'other systems', and accumulated changes affecting the next IPL) still apply. While you're there, search for other posts on that thread... interesting and enlightening reading. So I think what has been made clear is that the only thing necessary is to die. All else is up to you. If you re-IPL, know WHY you are doing so. Because Dad says so, isn't good enough any more. It was fine back in Dad's day, but things are different now. Is it for Security patches? Proactive maintenance? Configuration changes that can't be put into effect dynamically? Validation that your change control process is working properly? Just to remember how? As a demonstration of your power over the virtual machines (Never let the inmates run the prison.)? In the Golden Age of CMS, it was simple to shut down and restart. A few servers needed to be brought down nicely, but end users could be crushed with impunity (shutting down in 2 minutes...please logoff NOW was sufficient.) Today we have a different set of concerns to think about with Linux. Not only do we worry about less-tolerant file systems, we have more database managers and applications that like an orderly shutdown. If you are encountering z/VM operational errors that can be fixed only by IPLing, then I expect you have a PMR open. :-) Alan Altmark Senior Managing z/VM and Linux Consultant Lab Services System z Delivery Practice IBM Systems Technology Group ibm.com/systems/services/labservices office: 607.429.3323 mobile; 607.321.7556 alan_altm...@us.ibm.com IBM Endicott -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
On Friday, 05/29/2015 at 06:03 EDT, Graham Harris harris...@gmail.com wrote: Dumb question: Is live guest relocation of a z/Linux guest effectively a reboot of that guest, or does it transfer all the baggage that has accumulated over the life of the guest? LGR moves guest memory, registers, PSWs, MAC addresses, IP addresses -- whatever the guest had on the origin system, it has on the target system. While all that is happening, the guest still runs on the origin system. Near the end of the process, CP anesthetizes the guest, moves remaining tidbits, and revives it on the target system. Alan Altmark Senior Managing z/VM and Linux Consultant Lab Services System z Delivery Practice IBM Systems Technology Group ibm.com/systems/services/labservices office: 607.429.3323 mobile; 607.321.7556 alan_altm...@us.ibm.com IBM Endicott -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
But you can clean it up first!Use Sir Rob's wonderful cmmflush... That's good to know. Thanks Marcy, Rob. I wonder if there is still time to get that into the next Virtualization Cookbook? -Mike M. On Fri, May 29, 2015 at 6:09 PM, Marcy Cortes marcy.d.cor...@wellsfargo.com wrote: All memory so yes, all the baggage, cache, etc. But you can clean it up first!Use Sir Rob's wonderful cmmflush We clean up hundreds of dev servers every night and it has saved real $ https://zvmperf.wordpress.com/2012/07/06/using-cmm-to-flush-a-linux-guests-memory/ https://zvmperf.wordpress.com/2015/02/11/user-experience-with-cmmflush/ Marcy -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Graham Harris Sent: Friday, May 29, 2015 3:03 PM To: LINUX-390@VM.MARIST.EDU Subject: Re: [LINUX-390] Are weekly z/VM IPLs necessary? Dumb question: Is live guest relocation of a z/Linux guest effectively a reboot of that guest, or does it transfer all the baggage that has accumulated over the life of the guest? On 28 May 2015 at 23:48, Mike Walter mike.wal...@aon.com wrote: Enter the Wayback Machine for trip to 1996 by visiting: http://listserv.uark.edu/cgi-bin/wa?A2=ind9610L=IBMVMP=R10161=IBMVM 9=AI=-3J=onX=D2B166CA66E8CA0104Y=Mike.Walter%40aon.comd=No+Match %3BMatch%3BMatchesz=4 (watch out for URL line breaks of that link). That post was written before Linux ran on any IBM mainframes, and it addresses some CMS application issues, but some parts (e.g. 'other systems', and accumulated changes affecting the next IPL) still apply. While you're there, search for other posts on that thread... interesting and enlightening reading. While z/VM can shutdown and restart at astonishingly speed (well under 10 minutes), large Linux servers can take much longer -- making the business case for more frequent IPLs a more difficult decision. But one must balance weekly IPLs against the potential for the extended recovery time which may (place your bets) be required to recover from those changes which have accumulated since the last IPL, and may detrimentally affect the next IPL. Provide your management with as many facts as you can find, and your advice, then let them make a decision -- that's why they get paid the big bucks, right? Mike Walter Aon Service Corporation The opinions expressed herein are mine alone, not necessarily those of my employer. -- In response to: -- Date:Wed, 27 May 2015 14:33:41 + From:Will, Chris cw...@bcbsm.commailto:cw...@bcbsm.com Subject: Are weekly z/VM IPLs necessary? We have gotten in the habit of IPLing our z/VM and zLinux guests every = Sunday during our standalone window. With the window shrinking and the = need for 24/7 availability is it really necessary to IPL every week? If = not what potential problems could we run into by not doing the IPL (memory = leaks, logs filling etc.). This is in comparison to the Intel side of the = shop (Red Hat, Windows) where they go months between IPLs. The only = benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and = is intended solely for the use of the individual(s) to whom this = communication is directed. If you are not the intended recipient, you are = hereby notified that any viewing, copying, disclosure or distribution of = this information is prohibited. Please notify the sender, by electronic = mail or telephone, of any unintended receipt and delete the original = message without making any copies. =20 Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are = nonprofit corporations and independent licensees of the Blue Cross and = Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff
Re: Are weekly z/VM IPLs necessary?
Dumb question: Is live guest relocation of a z/Linux guest effectively a reboot of that guest, or does it transfer all the baggage that has accumulated over the life of the guest? On 28 May 2015 at 23:48, Mike Walter mike.wal...@aon.com wrote: Enter the Wayback Machine for trip to 1996 by visiting: http://listserv.uark.edu/cgi-bin/wa?A2=ind9610L=IBMVMP=R10161=IBMVM9=AI=-3J=onX=D2B166CA66E8CA0104Y=Mike.Walter%40aon.comd=No+Match%3BMatch%3BMatchesz=4 (watch out for URL line breaks of that link). That post was written before Linux ran on any IBM mainframes, and it addresses some CMS application issues, but some parts (e.g. 'other systems', and accumulated changes affecting the next IPL) still apply. While you're there, search for other posts on that thread... interesting and enlightening reading. While z/VM can shutdown and restart at astonishingly speed (well under 10 minutes), large Linux servers can take much longer -- making the business case for more frequent IPLs a more difficult decision. But one must balance weekly IPLs against the potential for the extended recovery time which may (place your bets) be required to recover from those changes which have accumulated since the last IPL, and may detrimentally affect the next IPL. Provide your management with as many facts as you can find, and your advice, then let them make a decision -- that's why they get paid the big bucks, right? Mike Walter Aon Service Corporation The opinions expressed herein are mine alone, not necessarily those of my employer. -- In response to: -- Date:Wed, 27 May 2015 14:33:41 + From:Will, Chris cw...@bcbsm.commailto:cw...@bcbsm.com Subject: Are weekly z/VM IPLs necessary? We have gotten in the habit of IPLing our z/VM and zLinux guests every = Sunday during our standalone window. With the window shrinking and the = need for 24/7 availability is it really necessary to IPL every week? If = not what potential problems could we run into by not doing the IPL (memory = leaks, logs filling etc.). This is in comparison to the Intel side of the = shop (Red Hat, Windows) where they go months between IPLs. The only = benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and = is intended solely for the use of the individual(s) to whom this = communication is directed. If you are not the intended recipient, you are = hereby notified that any viewing, copying, disclosure or distribution of = this information is prohibited. Please notify the sender, by electronic = mail or telephone, of any unintended receipt and delete the original = message without making any copies. =20 Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are = nonprofit corporations and independent licensees of the Blue Cross and = Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
No - it's not a reboot --- it's moving the memory/paging to another z/VM system while the guest is running. Any 'baggage' would be identical.. Scott Rohling On Fri, May 29, 2015 at 3:02 PM, Graham Harris harris...@gmail.com wrote: Dumb question: Is live guest relocation of a z/Linux guest effectively a reboot of that guest, or does it transfer all the baggage that has accumulated over the life of the guest? On 28 May 2015 at 23:48, Mike Walter mike.wal...@aon.com wrote: Enter the Wayback Machine for trip to 1996 by visiting: http://listserv.uark.edu/cgi-bin/wa?A2=ind9610L=IBMVMP=R10161=IBMVM9=AI=-3J=onX=D2B166CA66E8CA0104Y=Mike.Walter%40aon.comd=No+Match%3BMatch%3BMatchesz=4 (watch out for URL line breaks of that link). That post was written before Linux ran on any IBM mainframes, and it addresses some CMS application issues, but some parts (e.g. 'other systems', and accumulated changes affecting the next IPL) still apply. While you're there, search for other posts on that thread... interesting and enlightening reading. While z/VM can shutdown and restart at astonishingly speed (well under 10 minutes), large Linux servers can take much longer -- making the business case for more frequent IPLs a more difficult decision. But one must balance weekly IPLs against the potential for the extended recovery time which may (place your bets) be required to recover from those changes which have accumulated since the last IPL, and may detrimentally affect the next IPL. Provide your management with as many facts as you can find, and your advice, then let them make a decision -- that's why they get paid the big bucks, right? Mike Walter Aon Service Corporation The opinions expressed herein are mine alone, not necessarily those of my employer. -- In response to: -- Date:Wed, 27 May 2015 14:33:41 + From:Will, Chris cw...@bcbsm.commailto:cw...@bcbsm.com Subject: Are weekly z/VM IPLs necessary? We have gotten in the habit of IPLing our z/VM and zLinux guests every = Sunday during our standalone window. With the window shrinking and the = need for 24/7 availability is it really necessary to IPL every week? If = not what potential problems could we run into by not doing the IPL (memory = leaks, logs filling etc.). This is in comparison to the Intel side of the = shop (Red Hat, Windows) where they go months between IPLs. The only = benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and = is intended solely for the use of the individual(s) to whom this = communication is directed. If you are not the intended recipient, you are = hereby notified that any viewing, copying, disclosure or distribution of = this information is prohibited. Please notify the sender, by electronic = mail or telephone, of any unintended receipt and delete the original = message without making any copies. =20 Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are = nonprofit corporations and independent licensees of the Blue Cross and = Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
All memory so yes, all the baggage, cache, etc. But you can clean it up first!Use Sir Rob's wonderful cmmflush We clean up hundreds of dev servers every night and it has saved real $ https://zvmperf.wordpress.com/2012/07/06/using-cmm-to-flush-a-linux-guests-memory/ https://zvmperf.wordpress.com/2015/02/11/user-experience-with-cmmflush/ Marcy -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Graham Harris Sent: Friday, May 29, 2015 3:03 PM To: LINUX-390@VM.MARIST.EDU Subject: Re: [LINUX-390] Are weekly z/VM IPLs necessary? Dumb question: Is live guest relocation of a z/Linux guest effectively a reboot of that guest, or does it transfer all the baggage that has accumulated over the life of the guest? On 28 May 2015 at 23:48, Mike Walter mike.wal...@aon.com wrote: Enter the Wayback Machine for trip to 1996 by visiting: http://listserv.uark.edu/cgi-bin/wa?A2=ind9610L=IBMVMP=R10161=IBMVM 9=AI=-3J=onX=D2B166CA66E8CA0104Y=Mike.Walter%40aon.comd=No+Match %3BMatch%3BMatchesz=4 (watch out for URL line breaks of that link). That post was written before Linux ran on any IBM mainframes, and it addresses some CMS application issues, but some parts (e.g. 'other systems', and accumulated changes affecting the next IPL) still apply. While you're there, search for other posts on that thread... interesting and enlightening reading. While z/VM can shutdown and restart at astonishingly speed (well under 10 minutes), large Linux servers can take much longer -- making the business case for more frequent IPLs a more difficult decision. But one must balance weekly IPLs against the potential for the extended recovery time which may (place your bets) be required to recover from those changes which have accumulated since the last IPL, and may detrimentally affect the next IPL. Provide your management with as many facts as you can find, and your advice, then let them make a decision -- that's why they get paid the big bucks, right? Mike Walter Aon Service Corporation The opinions expressed herein are mine alone, not necessarily those of my employer. -- In response to: -- Date:Wed, 27 May 2015 14:33:41 + From:Will, Chris cw...@bcbsm.commailto:cw...@bcbsm.com Subject: Are weekly z/VM IPLs necessary? We have gotten in the habit of IPLing our z/VM and zLinux guests every = Sunday during our standalone window. With the window shrinking and the = need for 24/7 availability is it really necessary to IPL every week? If = not what potential problems could we run into by not doing the IPL (memory = leaks, logs filling etc.). This is in comparison to the Intel side of the = shop (Red Hat, Windows) where they go months between IPLs. The only = benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and = is intended solely for the use of the individual(s) to whom this = communication is directed. If you are not the intended recipient, you are = hereby notified that any viewing, copying, disclosure or distribution of = this information is prohibited. Please notify the sender, by electronic = mail or telephone, of any unintended receipt and delete the original = message without making any copies. =20 Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are = nonprofit corporations and independent licensees of the Blue Cross and = Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
Enter the Wayback Machine for trip to 1996 by visiting: http://listserv.uark.edu/cgi-bin/wa?A2=ind9610L=IBMVMP=R10161=IBMVM9=AI=-3J=onX=D2B166CA66E8CA0104Y=Mike.Walter%40aon.comd=No+Match%3BMatch%3BMatchesz=4 (watch out for URL line breaks of that link). That post was written before Linux ran on any IBM mainframes, and it addresses some CMS application issues, but some parts (e.g. 'other systems', and accumulated changes affecting the next IPL) still apply. While you're there, search for other posts on that thread... interesting and enlightening reading. While z/VM can shutdown and restart at astonishingly speed (well under 10 minutes), large Linux servers can take much longer -- making the business case for more frequent IPLs a more difficult decision. But one must balance weekly IPLs against the potential for the extended recovery time which may (place your bets) be required to recover from those changes which have accumulated since the last IPL, and may detrimentally affect the next IPL. Provide your management with as many facts as you can find, and your advice, then let them make a decision -- that's why they get paid the big bucks, right? Mike Walter Aon Service Corporation The opinions expressed herein are mine alone, not necessarily those of my employer. -- In response to: -- Date:Wed, 27 May 2015 14:33:41 + From:Will, Chris cw...@bcbsm.commailto:cw...@bcbsm.com Subject: Are weekly z/VM IPLs necessary? We have gotten in the habit of IPLing our z/VM and zLinux guests every = Sunday during our standalone window. With the window shrinking and the = need for 24/7 availability is it really necessary to IPL every week? If = not what potential problems could we run into by not doing the IPL (memory = leaks, logs filling etc.). This is in comparison to the Intel side of the = shop (Red Hat, Windows) where they go months between IPLs. The only = benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and = is intended solely for the use of the individual(s) to whom this = communication is directed. If you are not the intended recipient, you are = hereby notified that any viewing, copying, disclosure or distribution of = this information is prohibited. Please notify the sender, by electronic = mail or telephone, of any unintended receipt and delete the original = message without making any copies. =20 Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are = nonprofit corporations and independent licensees of the Blue Cross and = Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
I think Marcy's point is that if you can't think of the last time you booted Linux (or z/VM) -- then you're probably very behind on things like security and bug fixes... Scott Rohling On Thu, May 28, 2015 at 5:37 AM, Mark Pace pacemainl...@gmail.com wrote: I IPL z/VM only when CP maintenance is applied. I used to reboot/IPL my Linux guests at the same time. I no longer do that. I simply move them to another z/VM with LGR and after the z/VM IPL I move them back again. I can't think of the last time I had to reboot/IPL my Linux guests. On Wed, May 27, 2015 at 11:30 PM, Marcy Cortes marcy.d.cor...@wellsfargo.com wrote: You've gotten a lot of answers and they are worrisome! Here's my 5 or 6 cents. Yes, z/VM and Linux can go a very long time without being IPL'd/rebooted. Your applications may or may not. I would argue if they cannot, they need to solve the problem rather than clean it up with an IPL and/or reboot. If they need a reboot every weekend to clean up their memory problems, what happens if their volume doubles? Will they start rebooting every 3.5 days? We saw an app that started having very intermittent periods of weird delays after 5 or 6 weeks of uptime that was solved by an app recycle so they are now searching for a leak. I will add that I don't think I've ever seen an app leak problem affect Linux itself or for that matter VM itself - cycling the app or pkill -u appuser has been enough to clear up any memory issues. If someone asks your to recycle a server to solve an app problem , just say no ( Or more diplomatically, really??can't we try just recycling the app first?). The only ones I've seen that that was actually necessary on was when the OOM killer on Linux shot things, visible in the console. At that point reboot is inevitable and probably the server was short on memory to start with) . If you go more than a couple months on Linux or even on z/VM these days (and we all follow IBM ResourceLink Security for z/VM right?) , your patch policy is very generous or non-existent. I would say that we are at probably 5-6 VM IPLs per year to stay current (RSUs, releases, HW ucode), apply fixes we need (we find bugs, we apply fixes, we don't wait around to find the bugs that someone else already did) , and all security fixes. Linux is also averaging every other month for a reboot needed for kernel and/or glibc things that of course will require a reboot. Our challenge these days is to just coordinate those to same weekends so that there are change-free holiday weekends and system change free weekends so that those are available for application changes. PS - Our WMB (IIB) doesn't need weekly recycles as far as I've heard and we've been running that for probably 4 or 5 years. Its supporting some 70+ applications. These days when someone brags about uptime I'm not impressed. Watch the youtube from Share Seattle http://www.share.org/p/bl/et/blogaid=343 Yeah, it was z/OS, but is your tn3270 running encrypted and not subject to all the SSL bugs?! PPS to Sir Alan,: i need a card for the security weasel club, thanks :) Marcy -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Will, Chris Sent: Wednesday, May 27, 2015 7:34 AM To: LINUX-390@VM.MARIST.EDU Subject: [LINUX-390] Are weekly z/VM IPLs necessary? We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Are weekly z/VM IPLs necessary?
Scott R wrote: I think Marcy's point is that if you can't think of the last time you booted Linux (or z/VM) -- then you're probably very behind on things like security and bug fixes... Yup, that's what I'm trying to say. Probably in way too many words :)
Re: Are weekly z/VM IPLs necessary?
I IPL z/VM only when CP maintenance is applied. I used to reboot/IPL my Linux guests at the same time. I no longer do that. I simply move them to another z/VM with LGR and after the z/VM IPL I move them back again. I can't think of the last time I had to reboot/IPL my Linux guests. On Wed, May 27, 2015 at 11:30 PM, Marcy Cortes marcy.d.cor...@wellsfargo.com wrote: You've gotten a lot of answers and they are worrisome! Here's my 5 or 6 cents. Yes, z/VM and Linux can go a very long time without being IPL'd/rebooted. Your applications may or may not. I would argue if they cannot, they need to solve the problem rather than clean it up with an IPL and/or reboot. If they need a reboot every weekend to clean up their memory problems, what happens if their volume doubles? Will they start rebooting every 3.5 days? We saw an app that started having very intermittent periods of weird delays after 5 or 6 weeks of uptime that was solved by an app recycle so they are now searching for a leak. I will add that I don't think I've ever seen an app leak problem affect Linux itself or for that matter VM itself - cycling the app or pkill -u appuser has been enough to clear up any memory issues. If someone asks your to recycle a server to solve an app problem , just say no ( Or more diplomatically, really??can't we try just recycling the app first?). The only ones I've seen that that was actually necessary on was when the OOM killer on Linux shot things, visible in the console. At that point reboot is inevitable and probably the server was short on memory to start with) . If you go more than a couple months on Linux or even on z/VM these days (and we all follow IBM ResourceLink Security for z/VM right?) , your patch policy is very generous or non-existent. I would say that we are at probably 5-6 VM IPLs per year to stay current (RSUs, releases, HW ucode), apply fixes we need (we find bugs, we apply fixes, we don't wait around to find the bugs that someone else already did) , and all security fixes. Linux is also averaging every other month for a reboot needed for kernel and/or glibc things that of course will require a reboot. Our challenge these days is to just coordinate those to same weekends so that there are change-free holiday weekends and system change free weekends so that those are available for application changes. PS - Our WMB (IIB) doesn't need weekly recycles as far as I've heard and we've been running that for probably 4 or 5 years. Its supporting some 70+ applications. These days when someone brags about uptime I'm not impressed. Watch the youtube from Share Seattle http://www.share.org/p/bl/et/blogaid=343 Yeah, it was z/OS, but is your tn3270 running encrypted and not subject to all the SSL bugs?! PPS to Sir Alan,: i need a card for the security weasel club, thanks :) Marcy -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Will, Chris Sent: Wednesday, May 27, 2015 7:34 AM To: LINUX-390@VM.MARIST.EDU Subject: [LINUX-390] Are weekly z/VM IPLs necessary? We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Are weekly z/VM IPLs necessary?
Sounds like advice I got years ago (tail end of the 286 era) from a former co-worker... If you're blowing the dust off the motherboard it is well past the time to upgrade -soup On Thu, May 28, 2015 at 10:50 AM, Marcy Cortes marcy.d.cor...@wellsfargo.com wrote: Scott R wrote: I think Marcy's point is that if you can't think of the last time you booted Linux (or z/VM) -- then you're probably very behind on things like security and bug fixes... Yup, that's what I'm trying to say. Probably in way too many words :) -- John R. Campbell Speaker to Machines souperb at gmail dot com MacOS X proved it was easier to make Unix user-friendly than to fix Windows It doesn't matter how well-crafted a system is to eliminate errors; Regardless of any and all checks and balances in place, all systems will fail because, somewhere, there is meat in the loop. - me -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
No, FORCE is signal aware. From the HELP file: If the user is enabled for shutdown signals, the logoff is delayed unti either the amount of time defined by the system default shutdown signal timeout interval has elapsed or the user machine indicates that it has shut down, whichever occurs first. If the default timeout interval is 0 seconds, or the user is not enabled for shutdown signals, the logoff begins immediately. On 5/27/15, 11:19 AM, van Sleeuwen, Berry berry.vansleeu...@atos.net wrote: AFAIK a FORCE will kill the guest immediately instead of let it shutdown nicely. So when the linux guest is rebooted you will get a filesystemcheck for sure. And perhaps even file system errors that need to be fixed (manually).
Re: Are weekly z/VM IPLs necessary?
While we do not currently run z/Linux, we rarely IPL z/VM. Even in a previous work environment, we rarely would IPL z/VM. The IPL would usually occur at the Spring and Fall time change. But with changes to z/VM, we don't have to do that anymore. Do you really need to cycle z/Linux or is it maybe just a couple of apps that might need to be cycled? Granted, sometimes, it is just easier to cycle the operating system. Steve -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Will, Chris Sent: Wednesday, May 27, 2015 10:34 AM To: LINUX-390@VM.MARIST.EDU Subject: Are weekly z/VM IPLs necessary? We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
There are often odd things about restarts... One co-worker in a Unix environment told me of a fix that went in to keep a particular set of processes from coring out... and caused other problem (DNS lookups done only at the start of a process). When I heard this it reminded me of a story my son-- who's been in automotive service as well as IT for some time-- about Jaguar's biggest problem. Y'see, when Ford purchased Jaguar, they got new oil-tight engines... ... which removed the active rustproofing system Jaguar automobiles have had for some time. (chuckles) I saw the subject line and smirked. -soup -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
Ok - yes - a different situation...Availability is one of our key measurements, so I have much more incentive to keep z/VM available then it sounds like you do in this case ;-) Scott Rohling On Wed, May 27, 2015 at 8:19 AM, Duerbusch, Tom duerbus...@stlouis-mo.gov wrote: It really wouldn't. Our VM machines are really guests only. Other than me, no one else is actively logged on. (ok there are some others that use CMS ) Now a days, shutting down VM and restarting it, takes 2-3 minutes. Just not worth having a second set of procedures for something that happens every 590 to 1,537 days G). There are times I miss the old days... then I go home, grab a beer, and I get over it G. It it was really a problem, I would have a startup script that would test to make sure any guest is up that is required before the next guest is started. But then I could argue that the amount of down time required to test the script, and continued downtime to retest after images are enabled/disabled in the future, doesn't warrant the savings every couple of years. But, then, that is this shop. Tom Duerbusch THD Consulting On Wed, May 27, 2015 at 10:05 AM, Scott Rohling scott.rohl...@gmail.com wrote: This could help next time? pipe cp q signals | locate /Enabled/ | specs /FORCE/ 1 w1 nw | cons You can issue this safely to see what I'm talking about Change the 'cons' to 'CP' and each guest who has signal enabled (usually Linux and SFS) will get forced (signalled). Wait for them to come down and then autolog AUTOLOG1/2 or whatever to restart things. 'CP SHUTDOWN' essentially does the above and then brings z/VM down.. so this way you can bring down the guests and not z/VM itself.. Scott Rohling On Wed, May 27, 2015 at 7:55 AM, Duerbusch, Tom duerbus...@stlouis-mo.gov wrote: The last time we have IPL'ed either of our VM systems was due to a air conditioner failure (thermal shutdown of the z/890 box) 590 days ago. The only problem we had was with the zLinux side starting up. We got the messages: /dev/system/home has gone 1537 days without being checked, check forced. /dev/dasda1 has gone 931 days without being checked, check forced. /dev/dasda1 has gone 1075 days without being checked, check forced. Since check disk was being run, and the time they run varies by disk size (or disk used, or number of files or) the guests came up out of order. To fix it, we did the dumbest (ok easiest...requires no thinking) thing to do Wait for all 27 images to come up and go idle. Issue the shutdown script. IPL z/VM again and let AUTOLOG bring up all guests in the proper order. So, for some of us, the only time we need to IPL VM, is for a box swap, LPAR reconfiguration (add memory), maintenance to CP or installation of a new CP. It will be interesting to here what others had issues with. Tom Duerbusch THD Consulting On Wed, May 27, 2015 at 9:33 AM, Will, Chris cw...@bcbsm.com wrote: We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with
Re: Are weekly z/VM IPLs necessary?
This could help next time? pipe cp q signals | locate /Enabled/ | specs /FORCE/ 1 w1 nw | cons You can issue this safely to see what I'm talking about Change the 'cons' to 'CP' and each guest who has signal enabled (usually Linux and SFS) will get forced (signalled). Wait for them to come down and then autolog AUTOLOG1/2 or whatever to restart things. 'CP SHUTDOWN' essentially does the above and then brings z/VM down.. so this way you can bring down the guests and not z/VM itself.. Scott Rohling On Wed, May 27, 2015 at 7:55 AM, Duerbusch, Tom duerbus...@stlouis-mo.gov wrote: The last time we have IPL'ed either of our VM systems was due to a air conditioner failure (thermal shutdown of the z/890 box) 590 days ago. The only problem we had was with the zLinux side starting up. We got the messages: /dev/system/home has gone 1537 days without being checked, check forced. /dev/dasda1 has gone 931 days without being checked, check forced. /dev/dasda1 has gone 1075 days without being checked, check forced. Since check disk was being run, and the time they run varies by disk size (or disk used, or number of files or) the guests came up out of order. To fix it, we did the dumbest (ok easiest...requires no thinking) thing to do Wait for all 27 images to come up and go idle. Issue the shutdown script. IPL z/VM again and let AUTOLOG bring up all guests in the proper order. So, for some of us, the only time we need to IPL VM, is for a box swap, LPAR reconfiguration (add memory), maintenance to CP or installation of a new CP. It will be interesting to here what others had issues with. Tom Duerbusch THD Consulting On Wed, May 27, 2015 at 9:33 AM, Will, Chris cw...@bcbsm.com wrote: We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Are weekly z/VM IPLs necessary?
We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
Hi Chris, We IPL VM once a month, mostly to keep the operators in practice. The main challenge is spooled console logs getting so big or getting so old that when there is an IPL, the automated spool file maintenance routines delete them immediately. This is easily handled by an EXEC or two to close spools files at midnight. Peter -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Will, Chris Sent: May 27, 2015 10:34 AM To: LINUX-390@VM.MARIST.EDU Subject: Are weekly z/VM IPLs necessary? We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review retransmission dissemination or other use of or taking any action in reliance upon this information by persons or entities other than the intended recipient or delegate is strictly prohibited. If you received this in error please contact the sender and delete the material from any computer. The integrity and security of this message cannot be guaranteed on the Internet. The sender accepts no liability for the content of this e-mail or for the consequences of any actions taken on the basis of information provided. The recipient should check this e-mail and any attachments for the presence of viruses. The sender accepts no liability for any damage caused by any virus transmitted by this e-mail. This disclaimer is property of the TTC and must not be altered or circumvented in any manner. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
Therapeutic IPLs haven't been necessary for a number of years. It has been pointed out that large console logs can be closed for capture or retention, we do this daily. As far as bouncing a group of Linux guests, that can be scheduled separately and shouldn't require an IPL of VM. On 05/27/2015 09:33 AM, Will, Chris wrote: We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- Richard Smrcina Sr. Systems Engineer Velocity Software Inc. Main: (650) 964-8867 Main: (877) 964-8867 r...@velocitysoftware.com mailto://r...@velocitysoftware.com Signature http://www.velocitysoftware.com/ *Follow us:* facebook http://www.facebook.com/pages/Velocity-Software/356098274460840 LinkedIn http://www.linkedin.com/company/1798379?trk=tyah twitter https://twitter.com/VelocitySoftw Xing https://www.xing.com/companies/velocitysoftwaregmbh -- Richard Smrcina Sr. Systems Engineer Velocity Software Inc. Main: (650) 964-8867 Main: (877) 964-8867 r...@velocitysoftware.com mailto://r...@velocitysoftware.com Signature http://www.velocitysoftware.com/ *Follow us:* facebook http://www.facebook.com/pages/Velocity-Software/356098274460840 LinkedIn http://www.linkedin.com/company/1798379?trk=tyah twitter https://twitter.com/VelocitySoftw Xing https://www.xing.com/companies/velocitysoftwaregmbh -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
We IPL z/VM only when required by the implementation of maintenance or when a POR is needed on the box. We have gone 1.5 years between IPL's on z/VM and didn't have any issues. Linux was also designed to stay up indefinitely. Some of the test servers have been up for over a year with no issues. The prod servers are shut down and booted weekly only because we do this to obtain a clean backup (to tape) of the dasd volumes (all are ECKD volumes). While the prod servers are down, the mirrors to the 2nd set of volumes is 'broken' and the servers are booted. The mirror for a volume is automatically reestablished when the backup program, FDR, completes successfully. Harley Linker Jr. -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Will, Chris Sent: Wednesday, May 27, 2015 9:34 AM To: LINUX-390@VM.MARIST.EDU Subject: Are weekly z/VM IPLs necessary? We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ *** The information contained in this communication is confidential, is intended only for the use of the recipient named above, and may be legally privileged. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please resend this communication to the sender and delete the original message or any copy of it from your computer system. Thank You. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
It is not necessary -- I think most in this list would agree that the only time you want to IPL z/VM is when you apply CP maintenance or because of hardware changes... same with Linux (kernel or hw changes).Most of the systems I support have been up for many months. I go the opposite route -- my goal is to keep z/VM up as long as possible until I'm forced to bring it down or recycle it. The longer I can go the better I've done my job. Scott Rohling On Wed, May 27, 2015 at 7:33 AM, Will, Chris cw...@bcbsm.com wrote: We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
The last time we have IPL'ed either of our VM systems was due to a air conditioner failure (thermal shutdown of the z/890 box) 590 days ago. The only problem we had was with the zLinux side starting up. We got the messages: /dev/system/home has gone 1537 days without being checked, check forced. /dev/dasda1 has gone 931 days without being checked, check forced. /dev/dasda1 has gone 1075 days without being checked, check forced. Since check disk was being run, and the time they run varies by disk size (or disk used, or number of files or) the guests came up out of order. To fix it, we did the dumbest (ok easiest...requires no thinking) thing to do Wait for all 27 images to come up and go idle. Issue the shutdown script. IPL z/VM again and let AUTOLOG bring up all guests in the proper order. So, for some of us, the only time we need to IPL VM, is for a box swap, LPAR reconfiguration (add memory), maintenance to CP or installation of a new CP. It will be interesting to here what others had issues with. Tom Duerbusch THD Consulting On Wed, May 27, 2015 at 9:33 AM, Will, Chris cw...@bcbsm.com wrote: We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
It really wouldn't. Our VM machines are really guests only. Other than me, no one else is actively logged on. (ok there are some others that use CMS ) Now a days, shutting down VM and restarting it, takes 2-3 minutes. Just not worth having a second set of procedures for something that happens every 590 to 1,537 days G). There are times I miss the old days... then I go home, grab a beer, and I get over it G. It it was really a problem, I would have a startup script that would test to make sure any guest is up that is required before the next guest is started. But then I could argue that the amount of down time required to test the script, and continued downtime to retest after images are enabled/disabled in the future, doesn't warrant the savings every couple of years. But, then, that is this shop. Tom Duerbusch THD Consulting On Wed, May 27, 2015 at 10:05 AM, Scott Rohling scott.rohl...@gmail.com wrote: This could help next time? pipe cp q signals | locate /Enabled/ | specs /FORCE/ 1 w1 nw | cons You can issue this safely to see what I'm talking about Change the 'cons' to 'CP' and each guest who has signal enabled (usually Linux and SFS) will get forced (signalled). Wait for them to come down and then autolog AUTOLOG1/2 or whatever to restart things. 'CP SHUTDOWN' essentially does the above and then brings z/VM down.. so this way you can bring down the guests and not z/VM itself.. Scott Rohling On Wed, May 27, 2015 at 7:55 AM, Duerbusch, Tom duerbus...@stlouis-mo.gov wrote: The last time we have IPL'ed either of our VM systems was due to a air conditioner failure (thermal shutdown of the z/890 box) 590 days ago. The only problem we had was with the zLinux side starting up. We got the messages: /dev/system/home has gone 1537 days without being checked, check forced. /dev/dasda1 has gone 931 days without being checked, check forced. /dev/dasda1 has gone 1075 days without being checked, check forced. Since check disk was being run, and the time they run varies by disk size (or disk used, or number of files or) the guests came up out of order. To fix it, we did the dumbest (ok easiest...requires no thinking) thing to do Wait for all 27 images to come up and go idle. Issue the shutdown script. IPL z/VM again and let AUTOLOG bring up all guests in the proper order. So, for some of us, the only time we need to IPL VM, is for a box swap, LPAR reconfiguration (add memory), maintenance to CP or installation of a new CP. It will be interesting to here what others had issues with. Tom Duerbusch THD Consulting On Wed, May 27, 2015 at 9:33 AM, Will, Chris cw...@bcbsm.com wrote: We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to
Re: Are weekly z/VM IPLs necessary?
AFAIK a FORCE will kill the guest immediately instead of let it shutdown nicely. So when the linux guest is rebooted you will get a filesystemcheck for sure. And perhaps even file system errors that need to be fixed (manually). I would suggest: pipe cp q signals | locate /Enabled/ | specs /SIGNAL SHUTDOWN/ 1 w1 nw /WITHIN 300/ nw | cons Still no guarantee for a proper shutdown of guests though. When they haven't finished shutdown themselves they will get forced after the timer expires. We have a 'SHUTSYS' script that has the option to shutdown everything except VM itself. Perhaps an idea to add this to the shutdown script, option (NOIPL or something like that to prevent a VM IPL. Afterwards you can use the AUTOLOG1/2 machine to restart all services. Met vriendelijke groet/With kind regards/Mit freundlichen Grüßen, Berry van Sleeuwen -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Scott Rohling Sent: Wednesday, May 27, 2015 5:06 PM To: LINUX-390@VM.MARIST.EDU Subject: Re: Are weekly z/VM IPLs necessary? This could help next time? pipe cp q signals | locate /Enabled/ | specs /FORCE/ 1 w1 nw | cons You can issue this safely to see what I'm talking about Change the 'cons' to 'CP' and each guest who has signal enabled (usually Linux and SFS) will get forced (signalled). Wait for them to come down and then autolog AUTOLOG1/2 or whatever to restart things. 'CP SHUTDOWN' essentially does the above and then brings z/VM down.. so this way you can bring down the guests and not z/VM itself.. Scott Rohling On Wed, May 27, 2015 at 7:55 AM, Duerbusch, Tom duerbus...@stlouis-mo.gov wrote: The last time we have IPL'ed either of our VM systems was due to a air conditioner failure (thermal shutdown of the z/890 box) 590 days ago. The only problem we had was with the zLinux side starting up. We got the messages: /dev/system/home has gone 1537 days without being checked, check forced. /dev/dasda1 has gone 931 days without being checked, check forced. /dev/dasda1 has gone 1075 days without being checked, check forced. Since check disk was being run, and the time they run varies by disk size (or disk used, or number of files or) the guests came up out of order. To fix it, we did the dumbest (ok easiest...requires no thinking) thing to do Wait for all 27 images to come up and go idle. Issue the shutdown script. IPL z/VM again and let AUTOLOG bring up all guests in the proper order. So, for some of us, the only time we need to IPL VM, is for a box swap, LPAR reconfiguration (add memory), maintenance to CP or installation of a new CP. It will be interesting to here what others had issues with. Tom Duerbusch THD Consulting On Wed, May 27, 2015 at 9:33 AM, Will, Chris cw...@bcbsm.com wrote: We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff
Re: Are weekly z/VM IPLs necessary?
The main culprits are WMB (now called IIB) Execution Groups that are not well behaved from a memory management perspective. I agree that all we need is a recycle of these EGs but management is still concerned about potential z/VM and zLinux memory problems if we don't IPL. Chris Will -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Gentry, Steve Sent: Wednesday, May 27, 2015 10:40 AM To: LINUX-390@VM.MARIST.EDU Subject: Re: Are weekly z/VM IPLs necessary? While we do not currently run z/Linux, we rarely IPL z/VM. Even in a previous work environment, we rarely would IPL z/VM. The IPL would usually occur at the Spring and Fall time change. But with changes to z/VM, we don't have to do that anymore. Do you really need to cycle z/Linux or is it maybe just a couple of apps that might need to be cycled? Granted, sometimes, it is just easier to cycle the operating system. Steve -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Will, Chris Sent: Wednesday, May 27, 2015 10:34 AM To: LINUX-390@VM.MARIST.EDU Subject: Are weekly z/VM IPLs necessary? We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
On 5/27/2015 at 12:46 PM, Will, Chris cw...@bcbsm.com wrote: The main culprits are WMB (now called IIB) Execution Groups that are not well behaved from a memory management perspective. I agree that all we need is a recycle of these EGs but management is still concerned about potential z/VM and zLinux memory problems if we don't IPL. I seem to recall that outside expert opinions weigh more in situations like these. Now that you've gotten a bunch of those opinions, all pointing in the same direction, perhaps you can prevail in changing the practice. ;) Mark Post -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
Management is concerned? Based on what..? I'm not very helpful with 'feelings', I'm the first to admit;-) If they are really ok with shutting down all their guests for the sake of a few bad behaved ones we could just spank... well.. Scott Rohling On Wed, May 27, 2015 at 9:46 AM, Will, Chris cw...@bcbsm.com wrote: The main culprits are WMB (now called IIB) Execution Groups that are not well behaved from a memory management perspective. I agree that all we need is a recycle of these EGs but management is still concerned about potential z/VM and zLinux memory problems if we don't IPL. Chris Will -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Gentry, Steve Sent: Wednesday, May 27, 2015 10:40 AM To: LINUX-390@VM.MARIST.EDU Subject: Re: Are weekly z/VM IPLs necessary? While we do not currently run z/Linux, we rarely IPL z/VM. Even in a previous work environment, we rarely would IPL z/VM. The IPL would usually occur at the Spring and Fall time change. But with changes to z/VM, we don't have to do that anymore. Do you really need to cycle z/Linux or is it maybe just a couple of apps that might need to be cycled? Granted, sometimes, it is just easier to cycle the operating system. Steve -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Will, Chris Sent: Wednesday, May 27, 2015 10:34 AM To: LINUX-390@VM.MARIST.EDU Subject: Are weekly z/VM IPLs necessary? We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
On Wed, May 27, 2015 at 09:55:40AM -0500, Duerbusch, Tom wrote: The last time we have IPL'ed either of our VM systems was due to a air conditioner failure (thermal shutdown of the z/890 box) 590 days ago. The only problem we had was with the zLinux side starting up. We got the messages: /dev/system/home has gone 1537 days without being checked, check forced. /dev/dasda1 has gone 931 days without being checked, check forced. /dev/dasda1 has gone 1075 days without being checked, check forced. tune2fs will allow you to change the number of days (and reboots) between mandatory checks. Whether you should do that is another question, of course. -- Rodger Donaldsonrodg...@diaspora.gen.nz -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Are weekly z/VM IPLs necessary?
WMB aka IIB 9 guests are being cycled weekly here. They are not very well behaved. We use an in house written REXX to control the shutdown sequence and restart of the guest involved. We only IPL z/VM when we apply maintenance. We have gone more than a year without a z/VM IPL on many occasions. YMMV Doug . On May 27, 2015, at 16:17, Scott Rohling scott.rohl...@gmail.com wrote: Management is concerned? Based on what..? I'm not very helpful with 'feelings', I'm the first to admit;-) If they are really ok with shutting down all their guests for the sake of a few bad behaved ones we could just spank... well.. Scott Rohling On Wed, May 27, 2015 at 9:46 AM, Will, Chris cw...@bcbsm.com wrote: The main culprits are WMB (now called IIB) Execution Groups that are not well behaved from a memory management perspective. I agree that all we need is a recycle of these EGs but management is still concerned about potential z/VM and zLinux memory problems if we don't IPL. Chris Will -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Gentry, Steve Sent: Wednesday, May 27, 2015 10:40 AM To: LINUX-390@VM.MARIST.EDU Subject: Re: Are weekly z/VM IPLs necessary? While we do not currently run z/Linux, we rarely IPL z/VM. Even in a previous work environment, we rarely would IPL z/VM. The IPL would usually occur at the Spring and Fall time change. But with changes to z/VM, we don't have to do that anymore. Do you really need to cycle z/Linux or is it maybe just a couple of apps that might need to be cycled? Granted, sometimes, it is just easier to cycle the operating system. Steve -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Will, Chris Sent: Wednesday, May 27, 2015 10:34 AM To: LINUX-390@VM.MARIST.EDU Subject: Are weekly z/VM IPLs necessary? We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org
Re: Are weekly z/VM IPLs necessary?
You've gotten a lot of answers and they are worrisome! Here's my 5 or 6 cents. Yes, z/VM and Linux can go a very long time without being IPL'd/rebooted. Your applications may or may not. I would argue if they cannot, they need to solve the problem rather than clean it up with an IPL and/or reboot. If they need a reboot every weekend to clean up their memory problems, what happens if their volume doubles? Will they start rebooting every 3.5 days? We saw an app that started having very intermittent periods of weird delays after 5 or 6 weeks of uptime that was solved by an app recycle so they are now searching for a leak. I will add that I don't think I've ever seen an app leak problem affect Linux itself or for that matter VM itself - cycling the app or pkill -u appuser has been enough to clear up any memory issues. If someone asks your to recycle a server to solve an app problem , just say no ( Or more diplomatically, really??can't we try just recycling the app first?). The only ones I've seen that that was actually necessary on was when the OOM killer on Linux shot things, visible in the console. At that point reboot is inevitable and probably the server was short on memory to start with) . If you go more than a couple months on Linux or even on z/VM these days (and we all follow IBM ResourceLink Security for z/VM right?) , your patch policy is very generous or non-existent. I would say that we are at probably 5-6 VM IPLs per year to stay current (RSUs, releases, HW ucode), apply fixes we need (we find bugs, we apply fixes, we don't wait around to find the bugs that someone else already did) , and all security fixes. Linux is also averaging every other month for a reboot needed for kernel and/or glibc things that of course will require a reboot. Our challenge these days is to just coordinate those to same weekends so that there are change-free holiday weekends and system change free weekends so that those are available for application changes. PS - Our WMB (IIB) doesn't need weekly recycles as far as I've heard and we've been running that for probably 4 or 5 years. Its supporting some 70+ applications. These days when someone brags about uptime I'm not impressed. Watch the youtube from Share Seattle http://www.share.org/p/bl/et/blogaid=343 Yeah, it was z/OS, but is your tn3270 running encrypted and not subject to all the SSL bugs?! PPS to Sir Alan,: i need a card for the security weasel club, thanks :) Marcy -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Will, Chris Sent: Wednesday, May 27, 2015 7:34 AM To: LINUX-390@VM.MARIST.EDU Subject: [LINUX-390] Are weekly z/VM IPLs necessary? We have gotten in the habit of IPLing our z/VM and zLinux guests every Sunday during our standalone window. With the window shrinking and the need for 24/7 availability is it really necessary to IPL every week? If not what potential problems could we run into by not doing the IPL (memory leaks, logs filling etc.). This is in comparison to the Intel side of the shop (Red Hat, Windows) where they go months between IPLs. The only benefit I see is the opportunity to recycle WMB execution groups. Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
