2001-01-08-13:23:12 Brian Tao:
Both of those use 50GB and 72GB SCSI JBOD... probably about US$15K per terabyte, but still very fast and very reliable.
Hmm. JBOD can be "very reliable", it all depends on you getting lucky and getting a good batch of drives. But if all you want is fast and as reliable as your luck-of-the-drive-pick can get you, $15K/TB is kinda high; with the $250/80GB EIDE drives, on $50/4-channel RAID 0/1/0+1 controllers, run in pure striping for JBOD, a TB would be just 3 controllers full, $3000 for the drives, plus $150 for the controllers, plus however much you need to spend for the boxes to hold 12 drives. It's easy to find systems that will hold 4 drives comfortably for really cheap, so perhaps that's 3 boxes/TB, easy to assemble for $2k/ea, $6k/TB. And if you decide you want better reliability, go to RAID 0+1 for $12k/TB.
I'd rather not have any IDE drives in my servers if I can help it (and Sun is foiling that plan with their IDE CD-ROM's!) ;-)
I dunno, I've long built systems with nothing but SCSI, but I think these new drives re-open the question anyway for cases where performance is simply not a concern. Sure, they'll be slow, but if speed doesn't matter, and you can do RAID 0+1 with hardware raid controllers for less than the cost of JBOD using SCSI, I think I'd probably build the boxes with EIDE.
Please everyone, before you climb all over me and pound me to a pulp, note that I'm not advocating such homebrew hacks as an alternative to the Netapp. The discussion seems to me to be marginally relevant on the toasters list just because it's good to periodically stick your head up and peer around at the whole surrounding landscape, to see where you lie on it. But there's little overlap between Netapps (medium expensive, but breathtakingly fast, reliable, and effortless to administer, maintain, and back up) and this sort of homebrew disk farm (really really cheap, not especially fast, more or less reliable depending on whether you mirror and the quality of pieces you get, very very manual and systems admin intensive to set up and maintain).
Of course, the downsides to the cheap solution, which define Netapp's singular franchize, aren't guaranteed to remain in place forever, but they certainly apply today.
-Bennett