Mirrored Disk Failure in Normal Redundancy Mode. (A Failure Story Part 1)
IRON MAN WAS DOWN I’ve moved my blog from https://insanedba.blogspot.com to https://dincosman.com Please update your bookmarks and follow/subscribe at the new address for all the latest updates and content. More up-to-date content of this post may be available there. Lately, in our DR (Disaster Recovery) site, we have experienced two mirrored disk failures in normal redundancy mode which ended up with recreating of dataguard databases. I will try to explain our problem in detail. Our databases were down. CRS state was offline. ASM was down. Iron Man was down. We started diagnosing the issue with manually starting up the ASM instance on one node. We have 3 disk groups. 2 of them got mounted, but one disk group (+DATA) could not get mounted. This disk group (+DATA) was holding ocrconfig and serving as voting disk. This is the command and output. We checked all ASM instances alert.logs to clarify the chronological order of eve...