I do about 3.9TB for my full backup and around 650GB for my differentials.
When I stream to tape it takes 7 LTO3's.
Our SAN is all RAID-5, two LUNs are 2TB (8 drives, each) and one is 600GB (3 drives). Two fibre cabinets, one is full (13 active 300GB Fibre Channel drives, 1 hot spare), the...