We have two servers and currently only back up to tape. This turned out to be a huge problem when we had a server crash, as we learned the hard way that restoring from tape to a re-installed operating system is not supported or stable. Now we are looking at backing up to disk, but we are concerned about performance in a disk-to-disk-to-tape structure, so we are considering a SAN.  The configuration would look like this:

System Center 2012 R2 Datacenter Server (this is where most of the data resides)
v
SAN (this is going to allow the primary data source above to back up quickly)
v
System Center 2012 R2 Server with tape drive (this is a DC, and we want the data to go to tape quickly, making gigabit Ethernet an unacceptable alternative to SAN access)

Ideally, the "System Center Server with tape drive" would back itself up directly to the SAN, but it could back up to the SAN over gigabit Ethernet through the "System Center Datacenter Server" if that was safer.  Regardless, it would still need to access the same LUN as the System Center Datacenter Server in order to back up the disk data to tape.

I did a bit of searching, but wasn't able to find anything to confirm or deny the sanity of this configuration.  Can anyone confirm if and/or how this could work?

Hi,

You cannot have two windows servers access the same SAN LUN unless it's in a cluster.  DPM does not support using clustered disks in the storage pool, so the quick answer is that will not work.

<snip>
we learned the hard way that restoring from tape to a re-installed operating system is not supported or stable
>snip<

It should restore ok if you recover the machine using a BMR backup, or restore system state so it maintains it's original active directory machine account and ideally the same volume GUIDS.   So I would make system state backups a part of your backup strategy.

To be clear, backup directly to tape does not support BMR backup in DPM 2012R2, System State does not include applications and profiles, and restoring system volume data separately (even in the same session as the system state recovery, before or after the system state restore) leads to a multitude of issues.  Hence the need for a disk-based storage in case of future incidents.  That having been said, I was afraid that would be the answer, but I should be able to come up with an alternative or two (to the SAN plan).  Thank you.