One host in the vSAN cluster fails to enter maintenance mode with ensure accessibility mode.

Products

• VMware vSAN

Issue/Introduction

• You have 2 or more hosts contributing to the vSAN cluster before performing the maintenance mode (MM) task.
• When you try to place a host into maintenance mode with "Ensure Accessibility" (EA) mode; it may remain stuck for a long time and not complete.
• When you run the Data Migration Pre-check for EA, the test results in "The host cannot enter maintenance mode" and under "Predicted capacity and requirements", there is the message "The vSAN data cannot be migrated off the host".
• You only have policies with FTT=0 and FTT=1.

Environment

VMware vSAN 7.0.x

VMware vSAN 8.0.x

Cause

When there is one or more objects with FTT=0 that is not related to a registered VM in the inventory, it cannot be relocated during the maintenance mode task, which would prevent the decommissioning with EA of the owner host of the object(s).

Resolution

There are different ways to address this situation, depending on the object in question:

 

If the object data needs to be kept:

1. If the object is a vmnamespace, you can register the related VM into the inventory before performing the MM task.
2. If the object is a vdisk, you may attach the related vmdk to a registered VM or change the policy of the object to FTT=1.

 

If the object is related to an old VM that is not needed anymore:

1. Deleting the object(s) shall resolve the issue.