vSAN Objects in Reduced Availability with No Rebuild After Host Failure

Products

• VMware vSAN

Issue/Introduction

Symptoms:

In a VMware vSAN Original Storage Architecture (OSA) cluster, multiple objects report a status of reduced-availability-with-no-rebuild. This typically occurs following a host failure or removal in clusters utilizing RAID-6 (Erasure Coding). Symptoms include:

• vSAN Skyline Health displaying "Reduced Availability" warnings.

• Objects marked as "Non-Compliant" with assigned storage policies.

• Cluster host count dropping below the minimum requirement for the active policy.

• The "esxcli vsan debug object health summary get" command may indicate multiple objects are in the "reduced-availability-with-no-rebuild" state.
Health Status                                              Number Of Objects
---------------------------------------------------------  -----------------
remoteAccessible                                                           0
inaccessible                                                               0
reduced-availability-with-no-rebuild                                     285

 

 

Environment

• VMware vSAN 7.x

• VMware vSAN 8.x

 

Cause

The RAID-6 (Failures to Tolerate = 2) policy requires a minimum of 6 active hosts to satisfy placement rules. If the host count drops to 5, vSAN cannot maintain the requested redundancy level or perform a rebuild.

Resolution

1.Restore the cluster to the minimum required host count (6 hosts for RAID-6).

2.Repair or replace failed hardware and ensure the host is contributing to the vSAN datastore.

3.Monitor the automatic re-sync process once the 6th host is active.

4.Verify object health using the command: esxcli vsan debug object health summary get.

Workaround:

If a 6th host cannot be restored, modify the VM Storage Policy to align with available resources:

1. Navigate to Policies and Profiles > VM Storage Policies.

2. Edit the affected policy and change the Failure tolerance method to RAID-5 (requires 4 hosts) or RAID-1 (Failures to tolerate = 1).

3. Apply the policy to trigger object reconfiguration.