RE: Shared Memory challenge on AIX 5.1

>From what I remember of AIX 4.3 there is a configuration setting that by default limited the number of SHM segments per process to 10. Unfortunately having never used AIX 5.1 I cannot confirm if that is the same. However, if you go into smit and look for the section, I think, on OS parameters, that will tell you what the current setting is Regards Colin There are 10 types of people in the world, those that understand binary and those that don't >From: "Malcolm Weallans" <MWeallans@panacea.co.uk> >To: "Barry Leb" <bjleb@hotmail.com>, <informix-list@iiug.org> >Subject: RE: Shared Memory challenge on AIX 5.1 >Date: Mon, 23 Jan 2006 14:42:45 -0000 > >This is operating as 64-bit. I had heard about the limit on shared >memory segments and was surprised that I had as many as I did, but if >that is a 32/64 bit difference at least that one is explained. > >Thnks > >Malcolm > >-----Original Message----- >From: Barry Leb [mailto:bjleb@hotmail.com] >Sent: 23 January 2006 14:41 >To: Malcolm Weallans; informix-list@iiug.org >Subject: RE: Shared Memory challenge on AIX 5.1 > >Is this operating as 32 or 64 bit? If 32 bit you will run out of shared > >memory segments on AIX. I recall it to be 11 segments, tho there is >some >tinkering you can do with the environment variable EXTSHM to increase >the >number of segments grabbed by SHMADD. > > > >From: "mweallans@panacea.co.uk" <mweallans@panacea.co.uk> > >To: informix-list@iiug.org > >Subject: Shared Memory challenge on AIX 5.1 > >Date: 23 Jan 2006 04:04:10 -0800 > > > >One of my sites has 1 Gbyte of RAM. I have configured them to use > >512Mbytes of Virtual Shared Memory and about 256 Mbytes of Resident > >Share Memory. RESIDENT is set to 0. > >During normal processing everything is OK with those settings. > >Occasionally the size of the virtual shared memory rises from 512 > >Mbytes to about 700 Mbytes and there is no effect felt by the users. > >Last week the Virtual Shared Memory grew from 512 Mbytes to over 1.2 > >Gbytes in about 90 minutes, but once again there was no discernible > >effect on the users. Checking with ipcs and onstat -g seg shows that > >we have 12 virtual shared memory segments. > > > >The ONCONFIG parameters are:- > >SHMVIRTSIZE 524288 > >SHMADD 65536 > >SHMTOTAL 0> > > >Should I be concerned at using more shared memory than real memory? > > > >regards > > > >Malcolm > > > >_______________________________________________ > >Informix-list mailing list > >Informix-list@iiug.org > >http://www.iiug.org/mailman/listinfo/informix-list > > > > >- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - >PANACEA GROUP OF COMPANIES >Tel: +44 (0) 1256 30 50 50 >Visit us at: http://www.panacea.co.uk > >National Support Centre: >Tel: +44 (0) 1256 30 5000 >Get support at: http://www.support.panacea.co.uk > >- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - > >IMPORTANT NOTICE >This e-mail is intended only for the addressee named above and the contents >should not be disclosed to any other person or copies taken. If you have >received this e-mail in error, please notify us and delete the e-mail and >all attachments immediately. > >Any views or opinions presented are solely those of the sender and do not >necessarily represent those of Panacea Ltd. > >As Internet communications are not secure we do not accept legal >responsibility for the contents of this message or responsibility for any >change made to this message after it was sent by the original sender. We >have an anti-virus system installed on all our PCs and therefore any files >leaving us via e-mail will have been checked for known viruses. However we >advise you to carry out your own virus check before opening any >attachments, as we cannot accept liability for any damage sustained as a >result of any software viruses. > >Panacea Ltd reserves the right to monitor e-mails in accordance with the >Telecommunications (Lawful Business Practice) (Interception of >Communications) Regulations 2000. >_______________________________________________ >Informix-list mailing list >Informix-list@iiug.org >http://www.iiug.org/mailman/listinfo/informix-list

Colin Dawson wrote: > > >From what I remember of AIX 4.3 there is a configuration setting that by > default limited the number of SHM segments per process to 10. Unfortunately > having never used AIX 5.1 I cannot confirm if that is the same. However, if > you go into smit and look for the section, I think, on OS parameters, that > will tell you what the current setting is > > [cutting] AFAIK there was a hard limit of 10 on AIX3/4. Under 5 I think it has gone, but you should still try to minimise the number you have cheers Paul Paul Watson Oninit Ltd Tel : +44 1414161772 Cell : +44 7818 003457 Web : www.oninit.com

Don't 32bit versions of AIX still have that stupid limit of 2Gb of shared memory per process? Crap compared to Solaris having a 3.75Gb limit. That even worse that Windows that at least has the /3gb switch. Although I'm not sure that the /3gb switch affects windows since I don't use IDS on windows anywhere apart from at home!