Coincidentally I hit the same issue a couple of weeks ago. The corruption is noticed during a reconfiguration triggered when an ASM instance joins or leaves the cluster. It is seen in the Active Change Directory (file#3) which is the part of the ASM disk group analogous to the RDBMS redo stream which is used for instance recovery. In our case we shutdown a node non gracefully and noticed the 600 on the ASM instance of another node when the reconfig was triggered due to the first ASM instance going down. Also this is the 2nd ASM disk group corruption I have encountered in the past 6 months. Thanks Fairlie Edgar Chupit <chupit@xxxxxxxxx> wrote: We've recently hit bug #6163771 CANNOT MOUNT DISKGROUP DUE TO ORA-600 [KFCEMA02] on 10.2.0.2 (but it applies to >= 10.1.0.1 but < 11.2) After reboot of one instance, asm was failing to start because one of the diskgroups was corrupted due to this bug. There is a note 6163771.8 that describes this bug and the only workaround it is "There is no workaround - the diskgroup needs to be recreated.". Very bad thing about this issue is that, Oracle Support analyst was not able to reveal situation when it can happen, so I assume that it can happen anytime and to any diskgroup. In our case we were lucky, because affected diskgroup was used only as flash recovery area, so we didn't had to do actual restore, just moved flash recovery area to another place and than recreated the diskgroup. So, I think, there is billion + one case when RAC will not startup automagicaly. On Thu, Mar 20, 2008 at 4:11 PM, Bradd Piontek wrote: > I've seen that as well. It depends. > not really a question to be answered (i've currently got several SRs open) > but if anyone knows of common issues with the OCR corruption that would be > awesome. This has happened to us several times now. the diskgroup issue I -- Best regards, Edgar Chupit callto://edgar.chupit -- //www.freelists.org/webpage/oracle-l Fairlie Rego Senior Oracle Consultant http://el-caro.blogspot.com/ M: +61 402 792 405 --------------------------------- Get the name you always wanted with the new y7mail email address..