Requirements when replacing disks in a vSAN cluster

Products

• VMware vSAN

Issue/Introduction

Guidance on replacing disk drives in vSAN environments. 

 

Impact/Risks:

Failure to follow the requirements may result in undesired outcomes such as poor performance and data loss.

Symptoms:

One or more disks have failed in a vSAN cluster and requires replacement.

Environment

VMware vSAN 7.x

VMware vSAN 8.x

Resolution

Before replacing a failed disk in a vSAN cluster, ensure the following: 

• Disk must be certified for use with vSAN per the vSAN Compatibility Guide
  • Cache disk replacements must be certified for cache use.
  • Disk must be certified for vSAN configuration in use (hybrid/all-flash).
• Disk capacity should ideally be the same as the one being replaced. 
  • If the same size is not available, the next size up is acceptable.
• Disk performance and endurance classes must be the same or higher when compared to the original disk.

See Identifying specific disk failure in a vSAN deduplication cluster for more information.
See How to manually remove and recreate a vSAN disk group using esxcli for more information.

When replacing a failed capacity tier disk without Deduplication and Compression make sure to remove the failed disk from the disk group prior to pulling the disk from the host. See Replace a Capacity Device in vSAN Cluster for more details.

When replacing a failed cache tier disk or a capacity tier disk with Deduplication and Compression the entire disk group needs to be removed from vSAN prior to replacing the failed disk. See Replace a Flash Caching Device on a Host in vSAN Cluster & Add or Remove Disks with Deduplication and Compression Enabled for more details.