OMV ESXi Mount NFS Datastore Problems

Posted on 14-May-2022 by krylon

I had created an NFS share on OpenMediaVault, named EXAMPLE, with the following ACL permissions:

Owner: root, read/write/execute
Group: users, None
Others: None

When trying to mount the share (EXAMPLE) in ESXi,  the following error would occur:

Failed to mount NFS datastore EXAMPLE – Operation failed, diagnostics report: Cannot open volume: /vmfs/volumes/xxxx

The issue was permissions on the OMV side. By default NFS will squash root requests to anonymous.  There are 2 options, either will work, depending on your preference:

  1. Enable anonymous access on the OMV Shared Folder:  set the ACLs for Others to read/write/execute. Alternatively, you can change the Owner to nobody.  Be sure to set the Recursive option.
  2. Enable no_root_squash on the NFS Share

Then try to mount again.  If you receive this error

Failed to mount NFS datastore EXAMPLE – The name ‘EXAMPLE’ already exists.  Then run this in ESXi CLI

esxcli storage nfs remove -v EXAMPLE

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