hi, thanks all who replied. Darren Dunham pointed out, that wait io on a system with fast disks doesnt mean that the amount of requested io is very high so the disks are not slow. joe fletcher reported about a similar experience but they found out that the reporting tool did wrong reporting instead of the disks being slow . I read a similar thing on the internet pointing to mpstat not reporting correct. Some pointed to the hba and and said to get a new driver update. Others reminded that parallel to tuning the san side you can tune the oracle side. On www.orafaq.org is a good paper on the aspects of tuning oracle in a san enviroment. the tool to use is iostat to see the amount of wait queue and the percentage of disk usages. on the san side this would be symstat. thanks samier. Samier.Kesou@bfa.de An: sunmanagers@sunmanagers.org Gesendet von: Kopie: sunmanagers-admin@sunm Thema: wait io and SAN anagers.org 12.02.2003 13:38 Hello, we have a 12 CPU Server with a oracle database running on it OS: 5.8 oracle:8.1.7 SAN: EMC Symmetrix HBA: Emulex when running batch jobs we experience high values of wait io on all CPU's (20 - 60 % using mpstat). The amount for every single CPU is about the same. Performance checks on the SAN side didn't show any performance problems. I would have thought that SAN disks would have a better performance than that. Has anyone a similar experience or information about finding the cause of the wait io? thanks in advance, Samier. _______________________________________________ sunmanagers mailing list sunmanagers@sunmanagers.org http://www.sunmanagers.org/mailman/listinfo/sunmanagers _______________________________________________ sunmanagers mailing list sunmanagers@sunmanagers.org http://www.sunmanagers.org/mailman/listinfo/sunmanagersReceived on Thu Feb 13 04:41:39 2003
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