Oracle Automatic Storage Management
Recover from lost OCR disk group in Oracle Database 12c
How to recreate a lost OCR ASM disk group from scratch. This HowTo applies to Database 12c RAC. We will rebuild the disk group, restore the OCR, replace the voting disks, and recreate the ASM parameter and password files.
Oracle Database 12c: Flex ASM enable an existing cluster
This HowTo demonstrates migrating a RAC cluster to Flex ASM from 'traditional' ASM.
The prerequisites are that the OCR files, ASM parameter file and ASM password file are stored in an ASM disk group with asm.compatible set to at least 12.1. We will confirm the ASM cluster mode before we begin and after we have finished.