Re: External Page Usage
We were running 4.3. We are running 5.2 now. We didn't notice any increase in PAGE pack use, i.e, increased paging or physically using more page space. PAGE space allocation remained the same. Steve G. Schuh, Richard [EMAIL PROTECTED] Sent by: The IBM z/VM Operating System IBMVM@LISTSERV.UARK.EDU 08/09/2006 03:49 PM Please respond to The IBM z/VM Operating System To:IBMVM@LISTSERV.UARK.EDU cc: Subject:External Page Usage With our current configuration - 36GB main, 26GB XSTORE, 19 3390-03s for paging, we saw very low numbers ( 10%) when we entered Q ALLOC PAGE while running 4.4. Now, on 5.2, the results of the query show about 50% of the space is in use. Is this normal? Regards, Richard Schuh
Re: External Page Usage
More curiosity than anything. That seemed to be a drastic change in a number and I was wondering if it was normal or an indicator of a potential problem. I suspect it was the change in algorithm. Also, we have seen the number of TPF users increase by over 25% since we removed the 2G constraint. In any event, as long as page space occupancy doesn't go too much over 50% occupancy, I don't think I will worry about it. We bit that same page packs bullet before we threw money at the problem and jumped from 16G to 56G to eliminate dasd paging. Our numbers under 4.4 were about 50% before the storage increase. When the storage was later increased to 56G, the dasd usage was reduced to nearly 0 and practically all paging was between main and XSTORE. Now, we also see some dasd paging, but it is not anywhere close to a bothersome number. Regards, Richard Schuh -Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] Behalf Of Alan Ackerman Sent: Wednesday, August 09, 2006 9:47 PM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: External Page Usage We ran into something like this when we went from 4.4 to 5.1. We actually= ran out of page space. IBM pointed us to a page in a manual that said we should have enough page spa= ce for the sum of the size all our virtual machines. We Bit the bullet and got more page packs. I = don't remember details, but there were algorithm changes in 5.1. Once we added the page packs, I don'= t remember any actual problems with it. Do you really have a problem, or do you just not like the numbers you are= seeing? On Wed, 9 Aug 2006 13:49:00 -0700, Schuh, Richard [EMAIL PROTECTED] wrote= : With our current configuration - 36GB main, 26GB XSTORE, 19 3390-03s for= paging, we saw very low numbers ( 10%) when we entered Q ALLOC PAGE while running 4.4. Now, = on 5.2, the results of the query show about 50% of the space is in use. Is this normal? Regards, Richard Schuh = == ===
Re: External Page Usage
We ran into something like this when we went from 4.4 to 5.1. We actually ran out of page space. IBM pointed us to a page in a manual that said we should have enough page spa ce for the sum of the size all our virtual machines. We Bit the bullet and got more page packs. I don't remember details, but there were algorithm changes in 5.1. Once we added the page packs, I don't remember any actual problems with it. At the time, we had 16 3390-3 volumes dedicated to paging. The calculation showed that we should have 64, but we decided to try 32. I believe we had 32G of main storage and 4G of expanded storage at the time. IBM also said that their change to the paging algorithm had been too aggressive, and IIRC, they issued a PTF. We backed off to 4.4 until the PTF was ready, so I don't think we ever ran with the original 5.1 algorithm and 32 page volumes. We still have the 32 page volumes today, on z/VM 5.2.0 with 43G main/4G expanded. With our normal workload, the page space is 20% full.
Re: External Page Usage
-Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Schuh, Richard Sent: Wednesday, August 09, 2006 4:49 PM To: IBMVM@LISTSERV.UARK.EDU Subject: External Page Usage With our current configuration - 36GB main, 26GB XSTORE, 19 3390-03s for paging, we saw very low numbers ( 10%) when we entered Q ALLOC PAGE while running 4.4. Now, on 5.2, the results of the query show about 50% of the space is in use. Is this normal? Regards, Richard Schuh Richard, The obvious question is what else (other than the release of z/VM) has changed? Is the storage and paging configuration the same? Has minidisk cache been capped (so it's not consuming vast amounts of both main and expanded storage)? Is the workload the same or has it grown? Inquiring minds need to know these answers and more before making any suggestions or offering any hypotheses. Marty
Re: External Page Usage
No hardware changes at all (With our current config ...). MDC is capped the same as before (384M in main store). We did not want to change anything that we could leave the same in case of fall-back (something that had to do all too often.) Regards, Richard Schuh -Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] Behalf Of Marty Zimelis Sent: Wednesday, August 09, 2006 3:20 PM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: External Page Usage -Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Schuh, Richard Sent: Wednesday, August 09, 2006 4:49 PM To: IBMVM@LISTSERV.UARK.EDU Subject: External Page Usage With our current configuration - 36GB main, 26GB XSTORE, 19 3390-03s for paging, we saw very low numbers ( 10%) when we entered Q ALLOC PAGE while running 4.4. Now, on 5.2, the results of the query show about 50% of the space is in use. Is this normal? Regards, Richard Schuh Richard, The obvious question is what else (other than the release of z/VM) has changed? Is the storage and paging configuration the same? Has minidisk cache been capped (so it's not consuming vast amounts of both main and expanded storage)? Is the workload the same or has it grown? Inquiring minds need to know these answers and more before making any suggestions or offering any hypotheses. Marty
