Shared Memory/Semaphore Parameters for Sun 670 ??

Posted in 1994

A. J. Dibbins — 22 Feb 1994 06:03:09 -0500 — source: Informix-list mailing list archive (1991-1998)

Hi List Members, We have been troubled by this problem for some weeks now, and since Sun don't appear to have any idea, we were wondering if anybody out there might be able to throw some light on the matter. Old Set Up ========== We use to have a Sun 470 (96Mb SunOS 4.1.1) Sun DBE with the following kernel parameters set as indicated by DBE : SHMSIZE=0x20000 SEMMNS=640 SHMMNI=256 All other parameters set according to the defaults. This setup seemed to know no bounds as far as setting up a number of different onlines, five in total. New Set Up ========== This is an upgrade to the 470 to a 670 with 128Mb and now running SunOS 4.1.3_U1 with all the Informix products upgraded to match this operating system. We have tried this configuration with the default parameters, with the parameters supplied with the engine release notes, with DBE and without DBE and with and without the parameters suggested by the DBE manual. We have not been able to create a stable platform for the five existing onlines and are unable to create additional onlines without stealing resources from these existing onlines. The error message suggests that the number of semaphores or semaphore sets needs to be increased. Can anybody help with more information on the relationship between the semaphore parameters SEMMNI, SEMMSL and SEMMNS. The manual says Online uses one semaphore per database engine process so SEMMNS should equal the number of users + 4, for us about 80, anyway it is currently set as above, 640 (plenty) and SEMMSL should be at least 25, well it is set equal to SEMMNS according to "sem.h" so what about SEMMNI ? Can anyone offer any further info or experience it would be much appreciated. Thanks Andy Dibbins ------------------------------------------------------------------------------ HOME: SITE: Email: andy_d@rapier.demon.co.uk Email: X400 : aj.dibbins@old3ec.bt plc.bt.bt.gb Voice: +44 691 666714 Voice: +44 691 778626 FAX: +44 691 670750 -----------------------------------------------------------------------------