Re: Recycling servers ?
It has been my experience, that in a system with a lot of cache (meaning
the VM guest has too much memory allocated to it for the workload being
run, in most cases) that when you need memory, you will get it from cache
before you swap to disk. I tested this several times.
I also found a command that allows you to flush the buffers to disk, in
SLES8 called flushb.
I created a script to flush a small 2 disk system
#!/bin/sh
# Flush the buffers for /dev/dasdb1 and /dev/dasdc1
echo "Buffers before flush"
cat /proc/meminfo | grep Buffers
/usr/sbin/flushb /dev/dasdb1
/usr/sbin/flushb /dev/dasdc1
echo "Buffers after flush"
cat /proc/meminfo | grep Buffers
"Levy, Alan"
<[EMAIL PROTECTED]
gov> To
Sent by: Linux on [EMAIL PROTECTED]
390 Port cc
<[EMAIL PROTECTED]
IST.EDU> Subject
Recycling servers ?
09/03/2004 12:54
PM
Please respond to
Linux on 390 Port
<[EMAIL PROTECTED]
IST.EDU>
I currently have a few linux servers running in production (ZVM 4.4)
with heavy usage. Our IFL is only IPL'd once every few months. Would it
be advisable to recycle the whole machine (and all linux servers running
under VM) more than that ? I was told that linux servers have to be
rebooted periodically to clear out buffers, cache, storage, etc.
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Re: Recycling servers ?
> -Original Message- > From: Linux on 390 Port [mailto:[EMAIL PROTECTED] Behalf Of > Levy, Alan > Sent: Friday, September 03, 2004 12:54 PM > To: [EMAIL PROTECTED] > Subject: Recycling servers ? > > I currently have a few linux servers running in production (ZVM 4.4) > with heavy usage. Our IFL is only IPL'd once every few > months. Would it > be advisable to recycle the whole machine (and all linux > servers running > under VM) more than that ? I was told that linux servers have to be > rebooted periodically to clear out buffers, cache, storage, etc. You were told wrong. Unless you have an application with a memory leak, you don't need to reboot. I personally manage a Linux server (tucked safe behind a firewall so it is relatively safe from attack) with over 500 days of uptime and it's happy as a clam. -- Thomas Cameron, RHCE, CNE, MCSE, MCT Assistant Vice President Linux Design and Engineering Bank of America (972) 997-9641 The opinions expressed in this message do not necessarily reflect those of my employer, Bank of America. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Recycling servers ?
Nope...Getting mixed up with windows servers.. > -Original Message- > From: Levy, Alan [mailto:[EMAIL PROTECTED] > Sent: Friday, September 03, 2004 12:54 PM > To: [EMAIL PROTECTED] > Subject: Recycling servers ? > > > > I currently have a few linux servers running in production > (ZVM 4.4) with heavy usage. Our IFL is only IPL'd once every > few months. Would it be advisable to recycle the whole > machine (and all linux servers running under VM) more than > that ? I was told that linux servers have to be rebooted > periodically to clear out buffers, cache, storage, etc. > > > > > -- > For LINUX-390 subscribe / signoff / archive access > instructions, send email to [EMAIL PROTECTED] with the > message: INFO LINUX-390 or visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Recycling servers ?
Basic Engineering Rule 1: If it isn't broken, don't fix it. Basic Engineering Rule 2: If it doesn't cause problems, see rule 1. IPL only when you have a problem that you can't fix any other way. If you need to restart a Linux guest frequently, then you're better off finding and fixing the real problem than using the IPL to mask the symptom. -- db > I currently have a few linux servers running in production (ZVM 4.4) > with heavy usage. Our IFL is only IPL'd once every few > months. Would it > be advisable to recycle the whole machine (and all linux > servers running > under VM) more than that ? I was told that linux servers have to be > rebooted periodically to clear out buffers, cache, storage, etc. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Recycling servers ?
Talk to some folks used to running Linux server farms and they will pride themselves on how long their Linux machines stay up without the need for a therapeutic reboot. We're talking uptimes measured in years. You may need to find the right synergy between the application and the kernel release, but servers that need a periodic reboot may be suffering from a bug in one or the other. On Fri, 2004-09-03 at 12:54, Levy, Alan wrote: > > I currently have a few linux servers running in production (ZVM 4.4) > with heavy usage. Our IFL is only IPL'd once every few months. Would it > be advisable to recycle the whole machine (and all linux servers running > under VM) more than that ? I was told that linux servers have to be > rebooted periodically to clear out buffers, cache, storage, etc. > > > > > -- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 -- Rich Smrcina illustro Systems International, LLC --- See The Light--- Visit www.illustro.com to experience: z/Web-Host -- Easy Web-enabling for your Mainframe z/XML-Host -- Easy XML Enablement for your Mainframe Tel: +1.214.800.8900 Fax: +1.214.800.8989 Catch the WAVV! http://www.wavv.org WAVV 2005 - Colorado Springs - May 20-24, 2005 -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Recycling servers ?
> I was told that linux servers have to be rebooted periodically > to clear out buffers, cache, storage, etc. Not really. Linux is designed to reclaim/reuse/adjust as needed. Many people are quite proud of their uptimes... If you seem to be losing storage, I'd check on the virtual storage sizes of your long-running user-space programs first. ~ Daniel -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Recycling servers ?
We reIPL our VM systems twice a year at daylight savings time change. We probably don't need to do it that often except that some of our applications get upset when the time shifts by an hour. :-) _/) Tom Shilson ~GEDW & VM System Services Aloha Tel: 651-733-7591 tshilson at mmm dot com Fax: 651-736-7689 -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Recycling servers ?
We have a hard and fast policy of not IPLing the IFL more than once in any calendar quarter, and only then if we have something to change or fix. The servers themselves may be rebooted if there is a need from the customer. We've had linux servers (SLES8) running on VM (z/VM 4.4) for as much as six months at a time with no problems. Just like that bunny -- it keeps going and going... So one elephant says to another, "You'll never believe what happened last night. I was trying on Groucho Marx's pajamas--and he shot me!" Gordon Wolfe, Ph.D. (425)865-5940 VM Technical Services, The Boeing Company > -- > From: Levy, Alan > Reply To: Linux on 390 Port > Sent: Friday, September 3, 2004 10:54 AM > To: [EMAIL PROTECTED] > Subject: Recycling servers ? > > <> > > > I currently have a few linux servers running in production (ZVM 4.4) > with heavy usage. Our IFL is only IPL'd once every few months. Would it > be advisable to recycle the whole machine (and all linux servers running > under VM) more than that ? I was told that linux servers have to be > rebooted periodically to clear out buffers, cache, storage, etc. > > > > > -- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > > -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Recycling servers ?
Non virtual Linux servers, maybe. big maybe. Under VM you may need to cycle the virtual server once in a while, but the underlying VM and hardware rarely, perhaps when you've made major release or hardware changes. -Original Message- From: Linux on 390 Port [mailto:[EMAIL PROTECTED] Behalf Of Levy, Alan Sent: Friday, September 03, 2004 1:54 PM To: [EMAIL PROTECTED] Subject: Recycling servers ? I currently have a few linux servers running in production (ZVM 4.4) with heavy usage. Our IFL is only IPL'd once every few months. Would it be advisable to recycle the whole machine (and all linux servers running under VM) more than that ? I was told that linux servers have to be rebooted periodically to clear out buffers, cache, storage, etc. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 Confidentiality Warning: This e-mail contains information intended only for the use of the individual or entity named above. If the reader of this e-mail is not the intended recipient or the employee or agent responsible for delivering it to the intended recipient, any dissemination, publication or copying of this e-mail is strictly prohibited. The sender does not accept any responsibility for any loss, disruption or damage to your data or computer system that may occur while using data contained in, or transmitted with, this e-mail. If you have received this e-mail in error, please immediately notify us by return e-mail. Thank you. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Recycling servers ?
I currently have a few linux servers running in production (ZVM 4.4) with heavy usage. Our IFL is only IPL'd once every few months. Would it be advisable to recycle the whole machine (and all linux servers running under VM) more than that ? I was told that linux servers have to be rebooted periodically to clear out buffers, cache, storage, etc. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 <>
