vSAN diskgroup show unhealthy during patching ESXi hosts on vSAN cluster.

Products

• VMware vSAN

Issue/Introduction

• While patching ESXi hosts or post completing patching, vSAN diskgroup may show healthy on vCenter server skyline health.

• vSAN disk management may show diskgroup in failed state.

Environment

• VMware vSAN 8.x

• vSAN cluster host with physical disk replaced.

• Hardware is healthy on physical server.

Cause

• The issue is seen in cases, where there was a physical drive fault (cache disk) and was replaced by the hardware vendor. However, the diskgroup was never re-created (deleted failed diskgroup and create using replaced cache disk) which is required when the cache disk failure occur on vSAN cluster hosts.

• This can be validated by verifying the partition table on the replaced cache disk where it would not show vSAN partitions.

• The drive not used for vSAN would not show vsan and virsto.

# partedUtil getptbl /vmfs/devices/disks/<nre disk or replaced disk>
gpt
145921 255 63 2344225968

• The drive used for vSAN  would show the partition table as below. 

# partedUtil getptbl /vmfs/devices/disks/naa.####
gpt
145921 255 63 2344225968
1 2048 6143 381CFCCC728811E092EE000C2911D0B2 vsan 0
2 6144 2344225934 77719A0CA4A011E3A47E000C29745A24 virsto 0

• Also, the capacity disks of the failed diskgroup would be reporting VSAN Disk Group Name: empty.

naa.####
   Device: naa.####
   Display Name: naa.####
   Is SSD: false
   VSAN UUID: 52dc2a01-85d1-17f0-6669-########
   VSAN Disk Group UUID: 5222712a-4758-57cd-3acf-########
   VSAN Disk Group Name:                              <===============================
   Used by this host: true
   In CMMDS: false
   On-disk format version: 15
   Deduplication: false
   Compression: false
   Checksum: 8555403817375855139
   Checksum OK: true
   Is Capacity Tier: false
   Encryption Metadata Checksum OK: true
   Encryption: false
   DiskKeyLoaded: false
   Is Mounted: true

Resolution

Review and validate the drive was replaced and the diskgroup was not re-created.

Use the instructions in the KB 'Replace failed vSAN cache disk' and re-create diskgroup.