NFS datastores in a datastore cluster reporting incorrect free space used on the datastore
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NFS datastores in a datastore cluster reporting incorrect free space used on the datastore

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Article ID: 345630

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Updated On:

Products

VMware vSphere ESXi

Issue/Introduction

Symptoms:
  • NFS datastores in a datastore cluster reporting incorrect free space used on the datastore.

  • You see that datastores flapping between correct free space then wrong free space, then back and forth multiple times.

  • SDRS balancing datastores based on this incorrect information and multiple datastores had filled up all of their free space.


Environment

VMware vSphere ESXi 6.0
VMware vSphere ESXi 5.5
VMware vSphere ESXi 5.1

Cause

The vpxa service triggers a Refresh operation on datastores every 30 minutes. If there is no operation which changes storage information is running, the storage info will be refreshed every 30 minutes by vpxa. If there is any such operation is running, storage info refresh will be triggered at the end of that operation. The scheduled refresh does not happen on all the datastores connected, resulting in a smaller list provided by vpxd. This means fewer datastores are identified as subscribed datastores for each host and the refresh occurs only on subscribed datastores.

Therefore, if you are creating the VM on shared datastore from the host A, the host A datastore usage is updated. The host to which this datastore is subscribed is then updated within 30 minutes. If there are few other hosts in the cluster attached to the shared storage but the datastore is not subscribed on them, they will not get this update because no refresh occurs.

At this point, if the datastore usage is fetched from the host which is not yet refreshed, then UI will get the stale disk usage data resulting in an incorrectly reported datastore usage in vCenter and could force an incorrect rebalance.

Resolution

This is a known issue affecting VMware ESXi 5.x and 6.0.

This issue is resolved in VMware ESXi 6.0 Update 3, available at VMware Downloads.