Setting on BUFFERS parameter
Patrick couldn't raise BUFFERS beyond 600,000 on IDS 7.31.UC6A under HP-UX 11i (6 GB RAM); the engine failed with shmget ENOMEM / "mt_shm_init: can't create virtual segment" even after setting SHMMAX to 6 GB. Replies explained this is a 32-bit limit (the 'U' in UC6A), with HP-UX capping 32-bit shared memory at roughly 1.75 GB (up to ~2.75 GB via chatr), not an Informix configuration issue. The suggested fix was to move to the 64-bit port (7.31.FCx), noting the upgrade is one-way and 32-bit clients would then need socket rather than shared-memory connections, plus a reminder to tune page cleaners for large buffer pools.
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Hi, I am running IDS 7.31.UC6A on HP-UX 11i with 6 CPUs and 6 GB memory. Previously we set the BUFFERS to 80,000 only. After some testing, we change it to 600,000 and the performance is improved significantly. So we try to increase the value to test the performance again. We try 750000, 1000000 and so on but all failed. Only 600000 can work. And it show 16:33:18 Could not create single shared memory segment with resident and non-resident par titions. Proceeding to create 2 shared memory segments instead. 16:33:21 shmget: [ENOMEM][12]: key 52574802: out of shared memory, check system max shared memory segment size 16:33:21 mt_shm_init: can't create virtual segment We set the SHMMAX in kernel parameters to 6442450944 but still failed. Does anyone know what was happening. Is there some limitation on the Informix side ? Regards, Patrick
The limitation hides in IDS 7.31.UC6A - the 'U' always names 32bit IDS versions and there exist HP-UX limits with roughly 1,75 GB total 32bit shared memory (even if the HP-UX itself is 64bit; unless you use memory windowing options which is not really recommended). The solution is to upgrade to IDS 7.31.F.. (64bit). There exists almost no limit for shared memory usage. Attention: The upgrade from 32bit to 64bit normally runs very nice - a little bit longer than a upgrade from one 32bit version to the next. But I think it is NOT possible to revert to 32bit! AND: You can't connect from an application using 32bit libraries to a 64bit server using shared memory connections - you have to use socket connections (or upgrade/recompile your application). Regards, Andreas Kutsche > -----Ursprüngliche Nachricht----- > Von: forum.subscriber@iiug.org [mailto:forum.subscriber@iiug.org]Im > Auftrag von CHIM PATRICK > Gesendet: Mittwoch, 24. November 2004 09:06 > An: ids@iiug.org > Betreff: Setting on BUFFERS parameter [3766] > > > Hi, > > I am running IDS 7.31.UC6A on HP-UX 11i with 6 CPUs and 6 GB > memory. Previously we set the BUFFERS to 80,000 only. After > some testing, we change it to 600,000 and the performance is > improved significantly. So we try to increase the value to > test the performance again. We try 750000, 1000000 and so on > but all failed. Only 600000 can work. And it show > > 16:33:18 Could not create single shared memory segment with > resident and non-resident par > > titions. Proceeding to create 2 shared memory segments instead. > 16:33:21 shmget: [ENOMEM][12]: key 52574802: out of shared > memory, check system max shared memory segment size > 16:33:21 mt_shm_init: can't create virtual segment > > We set the SHMMAX in kernel parameters to 6442450944 but > still failed. Does anyone know what was happening. Is there > some limitation on the Informix side ? > > Regards, > Patrick > >
Hello, Yes, for the ids is 32bit version, and I think it could not use the momery exceed than 2G normally, again different OS, through you had set SHMMAX¡£ If you want to use much more memory, you should use the 64bit ids. FYI.... "CHIM PATRICK" <patrickchim@transunion-hk.com> Sent by: forum.subscriber@iiug.org 2004-11-24 16:06 To: ids@iiug.org cc: Subject: Setting on BUFFERS parameter [3766] Hi, I am running IDS 7.31.UC6A on HP-UX 11i with 6 CPUs and 6 GB memory. Previously we set the BUFFERS to 80,000 only. After some testing, we change it to 600,000 and the performance is improved significantly. So we try to increase the value to test the performance again. We try 750000, 1000000 and so on but all failed. Only 600000 can work. And it show 16:33:18 Could not create single shared memory segment with resident and non-resident par titions. Proceeding to create 2 shared memory segments instead. 16:33:21 shmget: [ENOMEM][12]: key 52574802: out of shared memory, check system max shared memory segment size 16:33:21 mt_shm_init: can't create virtual segment We set the SHMMAX in kernel parameters to 6442450944 but still failed. Does anyone know what was happening. Is there some limitation on the Informix side ? Regards, Patrick
Hi, You will need 64 Bits IDS Version ... something like 7.31 FCx (U means 32 Bits, F means 64 Bits Port). By the way: You also need to adjust Page Cleaners with large Buffers. -----Original Message----- From: forum.subscriber@iiug.org [mailto:forum.subscriber@iiug.org]On Behalf Of Guo Dong Wan Sent: quarta-feira, 24 de novembro de 2004 8:29 To: ids@iiug.org Subject: Re: Setting on BUFFERS parameter [3768] Hello, Yes, for the ids is 32bit version, and I think it could not use the momery exceed than 2G normally, again different OS, through you had set SHMMAX¡£ If you want to use much more memory, you should use the 64bit ids. FYI.... "CHIM PATRICK" <patrickchim@transunion-hk.com> Sent by: forum.subscriber@iiug.org 2004-11-24 16:06 To: ids@iiug.org cc: Subject: Setting on BUFFERS parameter [3766] Hi, I am running IDS 7.31.UC6A on HP-UX 11i with 6 CPUs and 6 GB memory. Previously we set the BUFFERS to 80,000 only. After some testing, we change it to 600,000 and the performance is improved significantly. So we try to increase the value to test the performance again. We try 750000, 1000000 and so on but all failed. Only 600000 can work. And it show 16:33:18 Could not create single shared memory segment with resident and non-resident par titions. Proceeding to create 2 shared memory segments instead. 16:33:21 shmget: [ENOMEM][12]: key 52574802: out of shared memory, check system max shared memory segment size 16:33:21 mt_shm_init: can't create virtual segment We set the SHMMAX in kernel parameters to 6442450944 but still failed. Does anyone know what was happening. Is there some limitation on the Informix side ? Regards, Patrick
Are you running 64 bit? If not, I believe you are limited to a 1.75 Gig footprint for Informix. (Total of all informix configs). > > From: "CHIM PATRICK" <patrickchim@transunion-hk.com> > Date: 2004/11/24 Wed AM 03:06:13 EST > To: ids@iiug.org > Subject: Setting on BUFFERS parameter [3766] > > Hi, > > I am running IDS 7.31.UC6A on HP-UX 11i with 6 CPUs and 6 GB memory. Previously we set the BUFFERS to 80,000 only. After some testing, we change it to 600,000 and the performance is improved significantly. So we try to increase the value to test the performance again. We try 750000, 1000000 and so on but all failed. Only 600000 can work. And it show > > 16:33:18 Could not create single shared memory segment with resident and non-resident par > > titions. Proceeding to create 2 shared memory segments instead. > 16:33:21 shmget: [ENOMEM][12]: key 52574802: out of shared memory, check system max shared memory segment size > 16:33:21 mt_shm_init: can't create virtual segment > > We set the SHMMAX in kernel parameters to 6442450944 but still failed. Does anyone know what was happening. Is there some limitation on the Informix side ? > > Regards, > Patrick > >
katedart@bellsouth.net said: > Are you running 64 bit? If not, I believe you are limited to a 1.75 Gig > footprint for Informix. (Total of all informix configs). You can use chatr on HPUX for up to 2.75 GB with 32-bit IDS. >> From: "CHIM PATRICK" <patrickchim@transunion-hk.com> >> Date: 2004/11/24 Wed AM 03:06:13 EST >> To: ids@iiug.org >> Subject: Setting on BUFFERS parameter [3766] >> >> Hi, >> >> I am running IDS 7.31.UC6A on HP-UX 11i with 6 CPUs and 6 GB memory. >> Previously we set the BUFFERS to 80,000 only. After some testing, we >> change it to 600,000 and the performance is improved significantly. So >> we try to increase the value to test the performance again. We try >> 750000, 1000000 and so on but all failed. Only 600000 can work. And it >> show >> >> 16:33:18 Could not create single shared memory segment with resident >> and non-resident par >> >> titions. Proceeding to create 2 shared memory segments instead. >> 16:33:21 shmget: [ENOMEM][12]: key 52574802: out of shared memory, >> check system max shared memory segment size >> 16:33:21 mt_shm_init: can't create virtual segment >> >> We set the SHMMAX in kernel parameters to 6442450944 but still failed. >> Does anyone know what was happening. Is there some limitation on the >> Informix side ? -- Bye now, Obnoxio "C'est pas parce qu'on n'a rien à dire qu'il faut fermer sa gueule" - Coluche "I'm trying to see things your way, but I can't get my head up my ass" - JCH "Ogni uomo mi guarda come se fossi una testa di cazzo" - Marco I went to the airport to check in and they asked what I did because I looked like a terrorist. I said I was a comedian. They said, "Say something funny then." I told them I had just graduated from flying school. -- Ahmed Ahmed