vSAN Object Inaccessible after host failure when FTT=0 is defined by Storage Policy

Products

• VMware vSAN

Issue/Introduction

The vSAN controller was not detected after an unexpected host reboot.

Side effects: 

• vSAN objects inaccessible, vSAN health reporting red. 
• VMs cannot be powered on, or migrated to new host. 
• VM is inaccessible after rebooting it
• Production server down and became inaccessible following a reboot operation.

Environment

 vSAN All Versions

Cause

The Missing Disk Groups on the failed host due to the controller failure.

Inaccessible objects are expected as the storage policy in use was FTT0
Single VMDK failure occurred and object is inaccessible due to  Raid 0 policy, or an object that was in 'reduced availability' at time of failure. 

Resolution

If Raid 0, or FTT0, see What are vSAN Policies, is set for policy, this assumes the data is not critical. Where if a hardware failure occurs, this data is lost.

In such cases because of the RAID_0 policy the data must be recovered from a backup.