Re: Confused about PAV and linux
PAV should only be used when necessary - for MOSTLY READ devices only. For devices with write activity, I have examples where I/O response times get worse, not better. Assuming your objective is better service? keep it super simple, there are many more important places to focus when it comes to performance. Tyler Koyl wrote: Background: - Moving ~ 20 z/OS Oracle Databases to Oracle 10g on z/VM linux (Hello z10!) - Powers that be want to move everything to RHEL5. - San Disk is the Frankenstein 9990v that has Hitachi, Sun and StorageTek all over it. We have 2105 ECKD DASD running off it with 3390B and 3390A definitions. We see PAV bases and aliases under z/VM no prob. - No FCP at this point as FCP from the 9990v to the z9BC requires a San volume controller for IBM to support it. We don't have the SVC. Straight FICON ECKD is all we got and most are MOD9s (We wll be going bigger if we stick ECKD). I have done some reading. Some from old sources, some from new.I am a bit overloaded now. Am I correct that in order to get PAV working on the linux guest I only have to vary the volumes online to guest itself and the linux DASD driver will handle the PAV when required? I really don't have to mess around with multipath, mdadm or EVMS (we have some SLES)? In my testing with RHEL5 I can vary online the base and alias devices and all appears ok. The DASD driver finds which are the alias and the bases and the UIDs all point to the same device. Am I on the right path here? D. Tyler Koyl Management Analyst (Embedded image moved to file: pic08260.gif) Viterra Tel (306) 569-6122 Fax (306) 569-4382 mailto:[EMAIL PROTECTED] http://www.viterra.ca This e-mail and any attachment(s) are confidential and may be privileged. If you are not the intended recipient please notify me immediately by return e-mail, delete this e-mail and do not copy, use or disclose it. -- 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 begin:vcard fn:Barton Robinson n:Robinson;Barton adr;dom:;;PO 390640;Mountain View;CA;94039-0640 email;internet:[EMAIL PROTECTED] title:Sr. Architect tel;work:650-964-8867 note:If you can't measure it, I'm just not interested x-mozilla-html:FALSE url:http://velocitysoftware.com version:2.1 end:vcard
Re: Confused about PAV and linux
Thanks for you time Klaus. I have PAV working with multipathing under RHEL5. I can see io being driven from both base and alias devices through Perfkit. Tyler This e-mail and any attachment(s) are confidential and may be privileged. If you are not the intended recipient please notify me immediately by return e-mail, delete this e-mail and do not copy, use or disclose it. -- 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: Confused about PAV and linux
You were looking at the development stream version of the document. HyperPAV is neither in RHEL5 nor in SLES10. Klaus Bergmann -- 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: Confused about PAV and linux
Interesting. We were looking at the same document. The one you pointed me to is from November 17, 2006 and the one I was reading is from May, 2008, which specifically states: - The DASD device driver now handles aliases for block devices for you. A mulipath setup is no longer required for PAV. - The DASD device driver supports PAV and HyperPAV. Has this DASD device driver not implemented in RHEL5 as of yet? Tyler Klaus Bergmann <[EMAIL PROTECTED] ibm.com>To Sent by: Linux on LINUX-390@VM.MARIST.EDU 390 Portcc <[EMAIL PROTECTED] T.EDU> Subject Re: Confused about PAV and linux 11/07/2008 03:33 AM Please respond to Linux on 390 Port <[EMAIL PROTECTED] T.EDU> You need the multipath tools, here is a description of the setup: http://download.boulder.ibm.com/ibmdl/pub/software/dw/linux390/docu/l26chp01.pdf In the future zLinux will support HyperPAV. Then the DASD-driver controls the dynamic assignment of the aliases w/o involvement of the multipath tools. This, in combination with the DS8000 storage pool striping technology, helps to avoid bottlenecks in the disk-subsystem. Klaus Bergmann -- 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 This e-mail and any attachment(s) are confidential and may be privileged. If you are not the intended recipient please notify me immediately by return e-mail, delete this e-mail and do not copy, use or disclose it. -- 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: Confused about PAV and linux
You need the multipath tools, here is a description of the setup: http://download.boulder.ibm.com/ibmdl/pub/software/dw/linux390/docu/l26chp01.pdf In the future zLinux will support HyperPAV. Then the DASD-driver controls the dynamic assignment of the aliases w/o involvement of the multipath tools. This, in combination with the DS8000 storage pool striping technology, helps to avoid bottlenecks in the disk-subsystem. Klaus Bergmann -- 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
Confused about PAV and linux
Background: - Moving ~ 20 z/OS Oracle Databases to Oracle 10g on z/VM linux (Hello z10!) - Powers that be want to move everything to RHEL5. - San Disk is the Frankenstein 9990v that has Hitachi, Sun and StorageTek all over it. We have 2105 ECKD DASD running off it with 3390B and 3390A definitions. We see PAV bases and aliases under z/VM no prob. - No FCP at this point as FCP from the 9990v to the z9BC requires a San volume controller for IBM to support it. We don't have the SVC. Straight FICON ECKD is all we got and most are MOD9s (We wll be going bigger if we stick ECKD). I have done some reading. Some from old sources, some from new.I am a bit overloaded now. Am I correct that in order to get PAV working on the linux guest I only have to vary the volumes online to guest itself and the linux DASD driver will handle the PAV when required? I really don't have to mess around with multipath, mdadm or EVMS (we have some SLES)? In my testing with RHEL5 I can vary online the base and alias devices and all appears ok. The DASD driver finds which are the alias and the bases and the UIDs all point to the same device. Am I on the right path here? D. Tyler Koyl Management Analyst (Embedded image moved to file: pic08260.gif) Viterra Tel (306) 569-6122 Fax (306) 569-4382 mailto:[EMAIL PROTECTED] http://www.viterra.ca This e-mail and any attachment(s) are confidential and may be privileged. If you are not the intended recipient please notify me immediately by return e-mail, delete this e-mail and do not copy, use or disclose it. -- 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<>
