One of my customers is having severe RAC performance issues, which appeared a dozen times so far. Each time, the performance impact lasted around 10 minutes and caused basically a hang of the application. ASH investigation revealed that the time frame of performance issues exactly matches a DRM operation of the biggest segment of the database. During the problematic time period, there are 20-50 instead of 5-10 active sessions and they are mostly waiting for gc related events: “gc buffer busy”,”gc cr block busy”, “gc cr block 2-way”, “gc current block 2-way”, “gc current request”, “gc current grant busy”, etc.<\/p>\n
In addition, there is one single session which has wait event “kjbdrmcvtq lmon drm quiesce: ping completion<\/strong>” (on instance 1) and 1-3 sessions with wait event “gc remaster<\/strong>“. (on instance 2) The cur_obj# of the session waiting on “gc remaster” is pointing to the segment being remastered.<\/p>\n Does anybody have any experience with DRM problems with 10.2.0.4 on Linux Itanium?<\/p>\n I know that it is possible to deactive DRM, but usually it should be beneficial to have it enabled. I could not find any reports of performance impact during DRM operation on metalink. Support is involved but clueless so far.<\/p>\n Regards,
\nMartin<\/p>\n