Datastore does not match current VM policy. "Expected storage type does not match with cluster disk groups storage type" error noticed when trying to apply vSAN storage policy for non-compliant VMs

Products

• VMware vSAN

Issue/Introduction

Symptoms:

• VMs stored on the vSAN datastore are showing as non-compliant.
  
  
  
  
• Applying RAID 5 storage policy on a vSAN datastore gives an error: Datastore does not match current VM policy. "Expected storage type does not match with cluster disk groups storage type"
  
  
  

Validation:

• RAID-5/6 requires an All-flash configuration so SSH to all the vSAN nodes and run the below command to validate if all the disks are detected as SSD -
  
  eg: 
[root@esxi1:~] esxcli vsan storage list | grep -i ssd
   Is SSD: true
   Is SSD: false
   Is SSD: false

Environment

VMware vSAN 7.x

VMware vSAN 8.x

Cause

• This reported issue is noticed whenever there is a mix of Hybrid and All-flash vSAN nodes in the Cluster.
  
  Note : As per KB # 326537 Mixing Hosts with Hybrid and All-Flash Disk Groups is not supported in vSAN

Resolution

• Identify the host which is running hybrid config by clicking on vSAN cluster > Configure > Disk Management > Select the vSAN nodes > View disks > Check if the disk group is "All Flash" or "Hybrid".
  
  
  
  
• If the host has detected SSD disks as HDD and then you have created the disk groups on the host, then follow the below steps:
  
  

Note: Compare the disks utilized as HDD on vSAN node with hybrid configuration to other nodes to make sure the device is truly a SSD or not. Please proceed with the below steps only if the device was SSD since marking a HDD device as Flash/SSD will not increase the device's performance and may even lead to the performance related issues in the cluster.

• • Place the vSAN node into maintenance mode.
  • Then remove the hybrid disk groups.
  • If the capacity devices have falsely been identified as HDD, then mark it as Flash by selecting vSAN node > Configure > Storage device > Select the capacity disk > Mark it as Flash.
  • Rescan storage from the cluster level.
  • Create the disk group again on the vSAN node.