Though I don’t work with it directly, we are using a 7 TB (usable) SAN that replicates to a more simplified SAN off site.
You sure you don’t have a SAN?
I don’t know how you get that much storage on a C3000…
Yep, we use DAS and multiple nodes in a cluster for a few reasons
-built in high availability(one node in the cluster goes down, apps are still up and automatically revives itself when the node comes back)
-less expensive
-MPP, add machines and it gets faster (6 nodes are exactly 2x faster than 3 nodes).
A SAN would work, but there is no real advantage to having it. With the C3000 we generally have about 5TB of local disc but can store ~10TB.
Are you looking to replace tape backup solutions with disk based and replicate offsite? If so I would actually advise against NAS options and look at Virtual Tape Library’s with the data de-duplication.
Vendor choice is wide open however Data Domain by far one of the best company’s in this area. However if you are on a budget restriction look at Overland Storage Reo line.
For offsite replication many NAS, VTL’s and SAN’s have built in replication support the biggest thing here is a big enough pipe to send data down.
What backup software are you using?