Unused storage devices are ineligible to be claimed for vSAN disk group

Products

• VMware vSAN

Issue/Introduction

Symptoms:

• iSCSI storage device/volume presented to the vSAN ESXi host appear as ineligible to be claimed for vSAN in vSphere Client > vSAN Cluster > Configure > vSAN - Disk Management > Select host > View Disks > Ineligible and unclaimed:

  

• There are no partitions on the disks and the disks are unused. Validated by looking from vSphere Client > Host > Configure > Storage Devices > Select the device > Partitions.

Environment

VMware vSAN (All versions)

Cause

• Remote storage volumes presented to the ESXi host via iSCSI/FC is not supported to be used as vSAN disks.

• The vSAN requires direct, hardware-level access to the underlying physical disk features(caching, device health and so on).

• With storage (both local and remote)volumes, these features are masked and not available to the ESX host.

• For an HDD/SSD/NVMe to be eligible for use in vSAN, the storage device must be presented as RAID0 or as JBOD (passthrough/just a bunch of disks) to the vSAN ESX host.

Resolution

To resolve this issue:

1. The storage volumes cannot be claimed to be used for the vSAN datastore.

2. Supported vSAN local storage devices must be added in JBOD or RAID0 configuration to the ESXi host, in-order to claim the devices for vSAN.

3. To check vSAN compatibility:

   • For vSAN storage devices: HDD | SSD / NVMe

   • For vSAN storage controller: vSAN I/O Controller