I have a couple of Buffalo Terrastations and I want to take the one with 4 x 500Mb drives in a RAID 5 and replace them with 2Tb drives. Since I'm accessing this NAS over my network, would I be okay sticking in 5400 drives or should I go with 7200? Will I see an I/O speed difference since, again, I'm accessing these NAS devices over an ethernet cable via my network rather than a faster route, like eSATA?
With a single 1 Gb NIC you would be safe to use 5400 disks, but with teamed NIC's or higher speed backbones, no.
Harm (or anyone) one more question: I mostly use these NASs for backup, so I don't need the discs spinning 24/7. What are your thoughts on drives that will spin down after a timeout? I know it can be annoying to wait for all 4 of them to spool up again, but I'm thinking it's probably better not to leave them spinning 24/7. Your thoughts? And I'm open to those Hitachi's that you seem to favor if that's your answer!