How to remove a disk from a vSAN disk group/host

Products

• VMware vSAN

Issue/Introduction

• This article provides steps to safely remove a disk from a vSAN disk group.

Symptoms:

• vSAN disk reports as failed
• Disk groups need to be resized to meet company needs

Environment

VMware vSAN 6.5.x
VMware vSAN 6.7.x
VMware vSAN 7.0.x
VMware vSAN 8.0.x
VMware vSAN 6.2.x
VMware vSAN 6.0.x
VMware vSAN 6.6.x
VMware vSAN 6.1.x

Resolution

From vCenter Web Client
1) Confirm if Deduplication and Compression is in use or not
2) Place the host into maintenance mode with Ensure Accessibility
3) If dedup is not in use then go to vSAN Cluster > Configure > Disk Management > Select the disk to be removed > Confirm no data impact with the Pre-Check Data Migration > If no data impact then select Remove Disk(s)

6.5 vCenter Web Client

6.7 and higher Web Client

Note: As of version 7.0U1 and the introduction of Compression-Only Mode you can replace just the failed capacity tier disk if using Compression-Only. No need to recreate the entire disk group like you do if Dedup is enabled. This is because Compression-Only is applied per-disk basis and not disk group like Dedup is.

4) If dedup is in use then the entire disk group needs to be removed and recreated. vSAN Cluster > Configure > Disk Management > Select the disk group to be removed > Confirm no data impact with the Pre-Check Data Migration > If no data impact then select Remove Disk Group

6.5 vCenter Web Client

6.7 and higher Web Client


From ESXi command line follow KB How to manually remove and recreate a vSAN disk group using esxcli (2150567)

If the physical disk was removed from the host prior to removing the disk/disk group via vCenter Web Client then follow the above KB for removing the disk/disk group via ESXi CLI.

If the disk or disk group fails to remove for any reason open a case with vSAN support for further assistance.

Additional Information

Remove Disk Groups or Devices from vSAN
Adding or Removing Disks with Deduplication and Compression Enabled

Impact/Risks:

• The disk or disk group must be removed via vCenter Web Client prior to removing the physical disk from the host, otherwise the removal process will fail.
• Removal of a disk can potentially cause a PSOD or Host to go Unresponsive if not done properly.
• It is also advisable to have a good current backup of all data that resides on the vSAN datastore.
• The disk may come back after a reboot and may work normally again in some cases however it is advisable to do a health check at regular intervals to ensure the disk functionality is in fact functioning as intended and not accidental.