Re: ontape: bad performance

We had similar performance losses at several customer sites following the upgrade from 7.31.xC6 to 7.31.xD2. What we noticed as the critical symptom were increasing checkpoint lengths, until one site was averaging 18,000 seconds per checkpoint. This affected performance everywhere, but usually occurred during backups. It turned out that we were running into one of the side-effects of the fix to the arc_very_old_page bug (101062). One recommendation we tried was setting the following ONCONFIG parameter before bringing the engine online: CCFLAGS 0x400000 This gave us limited relief, as checkpoints dropped down to minutes, but, most importantly, it helped Informix support identify the problem. We were running into IDS bugs 150991 which is a result of the fix for bug 145675 which is a result of the fix for bug 101062. To make a long story short, we had to upgrade our customers to the 7.31.xC4 release to get past all traces of 101062, then set CCFLAGS, and turn off KAIO on AIX platforms. Here are a couple of IBM links for info on 101062 & CCFLAGS. I will warn you that IBM's website is less user friendly than the surlier members of this group. http://www-1.ibm.com/support/entdocview.wss?uid=swg21137719 http://www-1.ibm.com/support/docview.wss?uid=isg1pTechnote0303 Sincerely, Christopher Coleman Database Analyst Medication Management Mediware Information Systems, Inc.