Replication Target Proxy Question

[jbarrow.viracoribt]

I have a question in regards to a replication proxy functionality.

Production Site:
Fiber Channel SAN
Fiber Channel Connected Physical Proxy

From what I understand, with the hardware above, it would be best to configure the proxy to use Direct SAN Access as the transport mode for best performance. In doing so, data will be pulled by the proxy over fiber channel.

DR Site:
Fiber Channel SAN
Fiber Channel Connected Physical Proxy

Now, when the production proxy sends data to the DR proxy it's going to go over Ethernet. But once the DR proxy has that data, how does it get it into the VMware environment? Does it come back out through Ethernet, into the VMware environment or would it still be utilizing the direct fiber channel connectivity for this? I'm just wondering if the direct Fiber Channel connectivity on the target side of this design will be utilized at all.

Thanks!

[foggy]

Jonathan, yes, you can configure direct SAN on the target, however it has some limitations.

[jbarrow.viracoribt]

1. The Direct SAN Access transport mode is not supported for VMs residing on vSAN. You can use Virtual Appliance and Network transport modes to process such VMs. For details on vSAN restrictions, see VDDK 5.5 Release Notes.
I don't think we utilize vSAN's here, we have a NetApp FAS8020.

2. The Direct SAN Access mode cannot be used if at least one VM disk is located on a VVol.
I don't think we utilize VVol's here either.

3. Veeam Backup & Replication uses the Direct SAN Access mode to read and write VM data only during the first session of the replication job. During subsequent replication job sessions, Veeam Backup & Replication will use the Virtual Appliance or Network transport mode on the target side. The source side proxy will keep reading VM data from the source datastore in the Direct SAN Access mode.
Veeam Backup & Replication writes VM data to the target datastore in the Direct SAN Access mode only if disks of a VM replica are thick-provisioned. If disks are thin-provisioned, Veeam Backup & Replication will write VM data in the Network or Virtual Appliance mode. By default, Veeam Backup & Replication replicates VM disks in the thin format. To write VM data to the target datastore in the Direct SAN Access mode, select to convert VM disks to the thick format at the Destination step of the replication job wizard.
So this seems applicable to us. It sounds like initial replication only would utilize FC, after that it's all ethernet via either Network or HotAdd. So FC could be helpful on the initial seed after that it's not really utilized at all it seems. We also use thin provisioning for many VM's so it sounds like for all those VM's, FC would not be used.

4. The Direct SAN Access transport mode can be used to restore only thick VM disks.
How is this applicable in a replication scenario?

5. The Direct SAN Access transport mode cannot be used for incremental restore due to VMware limitations. Either disable CBT for VM virtual disks for the duration of the restore process or select another transport mode for incremental restore.
I think what this is saying is that if I had to restore, let's say 1 file off the D: drive of a replicated system, this individual file restore would come over the Network or HotAdd methods?

[jbarrow.viracoribt]

Here is how I think it will work.



At the 1001 site, we would retrieve data via Direct SAN using fiber channel using a FC connected physical proxy.
That physical proxy would send the data it collects out via Ethernet, to the DR side proxy.
Once that DR side proxy has that data, it sends it back out Ethernet into the VMware environment.
Once it's within the VMware environment it would travel over FC as that's the only way VMware can reach the SAN storage.

Does that sound right?