I have to find the stuff, but at the z Expo we were told that mixing DASD types in a page farm is BAAAAD! I don't remember right off hand why. Maybe someone else can chime in while I research.
On Thu, Nov 13, 2008 at 3:28 PM, Schuh, Richard <[EMAIL PROTECTED]> wrote: > What will be the effect, other than having additional space available, > of adding five mod 9 disks to the existing page farm of 35 mod 3s? Would > there be a noticeable change in the performance of the paging subsystem? > (I suspect that any change will be less noticeable than the effects of > filling both page and spool. :-) ) > > Regards, > Richard Schuh > > > > > -----Original Message----- > > From: The IBM z/VM Operating System > > [mailto:[EMAIL PROTECTED] On Behalf Of Barton Robinson > > Sent: Thursday, November 13, 2008 11:36 AM > > To: IBMVM@LISTSERV.UARK.EDU > > Subject: Re: Page Space > > > > Do the math.... Number one reason for ONE outage at each new > > z/linux installation is to fill up page space - guess you > > were lucky and had some extra spool space (no block paging so > > slow), so you luckily didn't take the outage - which makes > > your servers even slower.... > > > > > > > > > > Schuh, Richard wrote: > > > > > Don't presume. 92G real, 10 xstore. All MDC activity is in real, > > > limited to 384MB. And I do not know the color of the machine :-) > > > > > > Regards, > > > Richard Schuh > > > > > > > > > > > > > > >>-----Original Message----- > > >>From: The IBM z/VM Operating System > > >>[mailto:[EMAIL PROTECTED] On Behalf Of Marcy Cortes > > >>Sent: Thursday, November 13, 2008 10:29 AM > > >>To: IBMVM@LISTSERV.UARK.EDU > > >>Subject: Re: Page Space > > >> > > >>You didn't say how much real memory you have. Presumably less than > > >>60G > > >>:) > > >> > > >>You either add enough real memory or you add enough page > > space to hold > > >>them all (at less that 50% occupied. I don't think there > > are miracles > > >>available in this scenario. > > >> > > >> > > >> > > >>Marcy > > >> > > >>"This message may contain confidential and/or privileged > > information. > > >>If you are not the addressee or authorized to receive this for the > > >>addressee, you must not use, copy, disclose, or take any > > action based > > >>on this message or any information herein. If you have > > received this > > >>message in error, please advise the sender immediately by > > reply e-mail > > >>and delete this message. Thank you for your cooperation." > > >> > > >> > > >> > > >>________________________________ > > >> > > >>From: The IBM z/VM Operating System > > >>[mailto:[EMAIL PROTECTED] On Behalf Of Schuh, Richard > > >>Sent: Thursday, November 13, 2008 10:20 AM > > >>To: IBMVM@LISTSERV.UARK.EDU > > >>Subject: [IBMVM] Page Space > > >> > > >> > > >> > > >>Yesterday, we were running a test using 17 z/TPF virtual > > machines, 3GB > > >>each. This was in addition to the normal load on the system. During > > >>the test, which was not moving along very quickly, nothing was, I > > >>noticed that our page packs were 100% allocated, up from the usual > > >>10%. This stood out as a smoking gun, verified by watching the > > >>performance improve as each of the ids in the test logged off. I > > >>presume that this should have been expected; however, other matters > > >>have kept us so busy that we did not do the math. I imagine > > that the > > >>one way to avoid this type of problem, we expect a peak of > > >>approximately 150 concurrent z/TPF systems in the coming year, is a > > >>massive injection of paging DASD. Is this the only answer > > or are there > > >>any other steps that we can take to help? > > >> > > >>Regards, > > >>Richard Schuh > > >> > > > > > > > > > > > > -- Mark Pace Mainline Information Systems 1700 Summit Lake Drive Tallahassee, FL. 32317
