While testing and playing around with the new Direct NFS mode i ran into a issue that when a VM has a delta disk (a.k.a snapshot) Direct NFS would not work and that VM would go over Network backup. Well that was kinda unexpected.. I like this new Direct NFS feature al lot but these limitations are pretty annoying.
Deep within the user guide i found out that this is mentioned:
Also the quiescence part can be irritating when creating backup of let’s day a SQL machine.
Backup won’t fail and for those systems they will fall back to NBD mode but still.
Limitations for the Direct NFS Access Mode:
- Veeam Backup & Replication cannot parse delta disks in the Direct NFS access mode. For this reason, the Direct NFS access mode has the following limitations:
- The Direct NFS access mode cannot be used for VM’s that have at least one snapshot.
- Veeam Backup & Replication uses the Direct NFS transport mode to read and write VM data only during the first session of the replication job. During subsequent replication job sessions, the VM replica will already have one or more snapshots. For this reason, Veeam Backup & Replication will use another transport mode to write VM data to the datastore on the target side. The source side proxy will keep reading VM data from the source datastore in the Direct NFS transport mode.
- The Direct NFS access mode cannot be used if you process VMs with the Enable VMware tools quiescence option enabled.
- If a VM has some disks that cannot be processed in the Direct NFS access mode, Veeam Backup & Replication processes these VM disks in the Network transport mode.