Witness host space efficiency differs from the rest of the cluster.

Products

• VMware vSAN

Issue/Introduction

Symptoms:

• VM creation task fails with error: "Invalid virtual machine configuration. Object policy is not compatible with datastore space efficiency policy configured on the cluster".

• VM snapshot creation task also fails with the same error.

• VM vMotion may fail with error: "A general system error occurred: Launch failure ####-##-##T##:##:##.####### The VM failed to resume on the destination during early power on. Module VMMon power on failed. Cause: Module VMMon power on failed. ####-##-##T##:##:##.####### The VM failed to resume on the destination during early power on."".

Environment

VMware vSAN 7.x

VMware vSAN 8.x

Cause

• Cannot create an object in a vSAN Stretched cluster or a ROBO cluster with vSAN Storage Policy's Space efficiency set to "Compression only" or "Deduplication and compression".

• Witness host always has a Space efficiency of None.

• Due to this, when creating an object in a vSAN Stretched cluster or a ROBO cluster with Space efficiency policy set to "Compression only" or "Deduplication and compression", the object creation will fail with "Invalid virtual machine configuration. Object policy is not compatible with datastore space efficiency policy configured on the cluster" error message.

Resolution

• To resolve this issue change the vSAN Storage policy's Space Efficiency parameter to  "No preference".
• Navigate to vSphere Client > Menu > Policies and Profiles > VM Storage Policies > Select the Policy to be updated > Edit:

• This will result in the space efficiency defaulting to the the selected datastore.

 

Note: If this change is made on a Storage Policy which is already applied to VMs, it can cause resync to occur, which can potentially impact performance. Recommended to clone the existing policy and make the above changes to the cloned policy, post which the cloned Policy can be applied to VMs in batches.