Re: Allocating more shared memory in Informix/HP-UX 11.0
From: query_gurl@my-deja.com > >Are there any available patches that can be applied to Informix Dynamic >Server 7.31.FC2 that would help in allocating more shared memory? > >Currently we are running Informix on a HP-UX 11.0 Server with 4 gigs of >RAM. The 4 gigs of RAM is recognized by HP-UX, but Informix chokes >trying to allocate more then 800 meg. We think the problem lies in >allocating memory across quadrants. > >If possible we would like for Informix to be able to use 2.75 gigs of >RAM. If anyone can point me in the right direction that would be great! chatr is the right direction. There should be stuff in your release notes. You must have missed it. ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com
In article <8ctb54$t4$1@news.xmission.com>, Obnoxio The Clown <obnoxio@hotmail.com> wrote: > >From: query_gurl@my-deja.com >> >>Are there any available patches that can be applied to Informix Dynamic >>Server 7.31.FC2 that would help in allocating more shared memory? >> >>Currently we are running Informix on a HP-UX 11.0 Server with 4 gigs of >>RAM. The 4 gigs of RAM is recognized by HP-UX, but Informix chokes >>trying to allocate more then 800 meg. We think the problem lies in >>allocating memory across quadrants. >> >>If possible we would like for Informix to be able to use 2.75 gigs of >>RAM. If anyone can point me in the right direction that would be great! > >chatr is the right direction. There should be stuff in your release notes. >You must have missed it. The Informix release notes for HP-UX are traditionally somewhat thin. You'll do better searching the HP support site for patches that explicitly mention Informix. Informix only release-notes the stuff they had to fiddle with to pass their QA suite. You're on 11.0, so some things will be different from our experience. We're on 10.20 with the SHMEM_MAGIC kernel and utilities patch so we can get 2.75 GB of shared memory from the box. In 10.20 we had to chatr -M almost everything in $INFORMIXDIR/bin, and set shmmax to 1GB (2**30, not 10**9). Even then, all we could grab for cache is 970000 pages, or just under two full segments. As our fine clown mentioned, you'll probably have to run chatr -M in 11.0 as well--Informix comes tagged EXEC_MAGIC, not SHMEM_MAGIC, out of the box. Make sure that you're using best-fit, not first-fit, shared memory allocation. In 10.20 this is an adb patch to the running system at start-up. Not sure what this looks like in 11.0. (Another 10.20 gotcha: best-fit only works in two quadrants, and not the extra one that SHMEM_MAGIC can use ...) Watch for memory fragmentation. If RESIDENT is -1, and you bounce the server a lot, HP-UX 10.20 and 11.00 get very slow in locking memory. We've used Glance to measure one call to shmctl at over 6 minutes. HP's workarounds: either don't bounce the server, or reboot. -- W. Jim Jordan, Nortel Networks, Stop 29CA3A08 | +1 613 763 1568 PO Box 3511 Stn C, Ottawa, ON K1Y 4H7 Canada | wjjordan@nortelnetworks.com Opinions expressed are not necessarily those of Nortel Networks. Inbound spam filtering is in place. Don't send what I won't see.