3.6 What are Uniform and Non-uniform Exports?

Since Oracle VM Manager never connects directly to any storage, but relies on Oracle VM Servers to handle the administration and the discovery of file systems exported by the NFS file server, Oracle VM Manager requires that you designate an Oracle VM Server as an administrative server and an Oracle VM Server as a refresh server. These servers may be the same Oracle VM Server. If all servers within the deployment have the same access to file systems exposed by the filer, Oracle VM Manager understands these exports to be uniform.

In the case of uniform exports, a single Oracle VM Server may be designated for the purpose of performing file system refreshes, although another may be added for redundancy.

In some cases, an NFS file server may be configured to export mount points with various access restrictions. In the case where some Oracle VM Servers in a deployment are not able to access exports that are available to others, Oracle VM Manager understands these exports to be non-uniform. If the exports exposed by the NFS file server are non-uniform, a single Oracle VM Server may not have access to all of the exports available on the file server. In this case, multiple Oracle VM Servers may need to be designated for the task of refreshing NFS storage and the file systems that are available on the file server.

Non-uniform exports are not intended for servers within the same server pool. All of the servers that belong to a server pool that requires access to file systems on an NFS file server with non-uniform exports must be added to an access group. See Access Groups Perspective in the Oracle VM Manager User's Guide for more information on this.


If you need to refresh file systems for an NFS file server that has non-uniform exports, it is important to understand that for the operation to complete, each of the refresh servers must perform its own file system refresh, since each server has access to a different set of exports. If any of the refresh servers are unavailable, the job cannot complete, since not all exports can be refreshed. If you are faced with this situation, you may need to edit the NFS file server to remove a refresh server that is out of commission, and add an alternate that has access to the same set of file server exports.