On 06/22/2012 03:09 PM, Merrill Oveson wrote: > Building a server: > > one 1 TB - for the OS and programs. > > four 3 TB raid 5 - which should give me 9 TB usable. Correct? > > How reliable are the 3 TB drives these days? Am I taking a big risk here? > > thoughts?
correct, you'd have ~9TB usable. i have a 4 drive raid-5 with hitachi 3TB drives (HDS5C3030ALA630)that have been doing just fine. i just checked SMART data on the drives and there haven't been any errors that it reports and they all have about 5400 hours of power on time. they are in a box that doesn't get a whole lot of i/o traffic but they've been doing good for what they're meant for. i did buy 5 drives when i first build this array and didn't use 1 in the array cause it was making a noise the others weren't but its been in use in a desktop and no problems with it either. the drives i have are 'consumer' 'green' drives but there are 'enterprise' grade 3TB disks out there. so i wouldn't worry too much about the reliability just on the basis of size. as for the debate on the list about what raid level to use, i think it depends on multiple factors. how much activity are the disks going to be seeing? how much space is needed? etc. if you don't anticipate a lot of disk i/o, then you would probably be just fine with a raid 5. the concern expressed in the thread is that you need to rebuild before a second failure and that can take a while with large disks. if the disks are really busy, it could easily take days to weeks to rebuild. but if there isn't, the rebuild can complete in a matter of hours. iirc, a rebuild on my 4 drive raid 5 takes about 7 hours which isn't bad for my case. if you don't need the max amount of space available, i would probably do a raid 10 since it is much less computationally intense than a raid 5 or 6. imo raid 6 with just 4 drives is kind of a waste. so it depends a bit on what the array is going to be used for. mike /* PLUG: http://plug.org, #utah on irc.freenode.net Unsubscribe: http://plug.org/mailman/options/plug Don't fear the penguin. */
