After Double fault on a RAID 5 volume where ESXi and a local VMFS datastore resided, the existing VMFS datastore on Partition 8 is no longer visible after using the preserve volumes option while reinstalling ESXi.
ESXI (all versions)
Double fault on a RAID-5 volume will lead to data loss even If the backing volume could be rebuilt.
If you encounter issue please open a case with VMware by Broadcom Support for further investigation.
For more information on how RAID Works and the amount of failures each RAID type can handle please see https://en.wikipedia.org/wiki/RAID