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 requirements may result in undesired operation with outcomes ranging from poor performance up to and including data loss.

Symptoms:
One or more disks have failed in a vSAN cluster, requiring replacement.

Environment

VMware vSAN 7.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 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 & Adding or Removing Disks with Deduplication and Compression for more details.