Resync is not progressing on vSAN cluster during the vSAN cluster activity.

Products

• VMware vSAN

Issue/Introduction

• During the vSAN hosts maintenance and adding additional disks, the resync is not progressing.

• The data health on vSAN cluster shows in reduced availability.

Environment

VMware vSAN 8.x

VMware vSAN 9.x

Cause

• The issue is seen when one or more hosts are in vSAN decommission state. However, the host is out of maintenance mode.

• This can be validated by checking vSAN health where it would report warning for "Host Maintenance Mode" and it will not be in sync with vCenter/Host.

• Also, when you run the command 'esxcli vsan cluster get' on affected host, you would see the maintenance mode status show 'ON'.

Maintenance Mode State: ON

Resolution

Fix the vSAN layer DECOM issues using the instructions in the KB vSAN Health Service -- Host Maintenance Mode is in sync with vSAN Node Decommission State