12-C RAC all instance failure due to file system issues.
We have a two node 12-C RAC installed on RHEL7.2 for our pre-production environment. There were volumes mounted from Hitachi storage for oracle installation folder and ASM disks for database, where all the volumes where in the same host group of Hitachi storage. Two 500GB(mounted as /u01) volumes for oracle installation folder and two 1TB(mounted as /image) volumes for other storages where mounted individually to the nodes. The RAC was working fine but due to some power outage, both the server nodes got restarted one after other. On restart it was found that the 500GB partiion i.e. /u01 has some