Informix and Kernel Parameters

Greetings This is kind of off topic... but not really. I'm trying to tune an Informix Database engine running on a Sun "StarFire" (E10000) with 32 cpus/ 32 Gig of memory Solaris 2.6.... but the kernel parameter applies to a lot of UNICES. UNI. UNIE? The default bufhwm in Solaris is at 2%. (It was never set in /etc/system) This means that 320 Meg of memory is being used as an inode buffer. (the name bufhwm is not what it looks like... that' old UNIX versus new UNIX stuff.) Anyway, all sources I've seen say that having this set that way could cause EXTERME RDBMS SLOWDOWN. Our Informix crawls like a pig through cow pies. The best setting appears to be fairly small... like about 8 Meg. Anyone have experience with this? (I'm not the Sysadm and shouldn't have to be worrying about stuff like this... BUT hey..... it's a small world. I was a DBA 10 years ago.) Thanks, Keith

Keith L Morris wrote: > > Greetings > > This is kind of off topic... but not really. I'm trying to tune an > Informix Database engine running on a Sun "StarFire" (E10000) with 32 > cpus/ 32 Gig of memory > > Solaris 2.6.... but the kernel parameter applies to a lot of UNICES. > UNI. UNIE? > > The default bufhwm in Solaris is at 2%. (It was never set in > /etc/system) This means that 320 Meg of memory is being used as an > inode buffer. > (the name bufhwm is not what it looks like... that' old UNIX versus new > UNIX stuff.) > > Anyway, all sources I've seen say that having this set that way could > cause EXTERME RDBMS SLOWDOWN. > > Our Informix crawls like a pig through cow pies. > > The best setting appears to be fairly small... like about 8 Meg. Does not sound right to me. I do not see how haveing 320MB out of 32GB dedicated to inode caching when Informix should be using RAW devices which do not use inodes anyway (well the symlinks do but...) will make any difference at all on engine performance. I'd look to the disk farm and engine tuning first. Have the DBA, or you, post the usual suite of onstat output and your onconfig file and disk far configuration (ie not all the partitions just how many drives in how many stripes of what kind of RAID???). We'll look it over. Art S. Kagel > Anyone have experience with this? > > (I'm not the Sysadm and shouldn't have to be worrying about stuff like > this... BUT hey..... it's a small world. I was a DBA 10 years ago.) > > Thanks, > Keith