Scott Reese wrote:
Greetings Hernan: You can, in theory, expand a software array and expand the filesystem one it. We have tried it with Debian Etch, and it worked. However, it took forever. It took almost 40 hours to to go from 1.2TB to 1.8TB. Time required to backup the entire filesystem to tape, verify the backup, delete the old array, add the disks, build a new array, and restore from tape: 18 hours. Since you are going to have to do a full backup before you try to expand array anyway, I can assure you that just deleting the old array, building a new one, and restoring from tape is the way to go.
Well... the problem is, of course, where do I put 1TB of data while I add the new disk :). I was thinking of just take the risk and do it. I was trying to get a tape backup unit. Tapes for 400/800GB are cheap, the problem is getting the tape backup unit. I saw some on ebay but they only sell to the US (and I'm not US-based). A tape backup unit costs US$ 2500 here in Argentina.
Why would I risk to lose all that data? Because I already have all of that on CD and DVD. If everything goes OK, then fine. If not, I'll just have to copy that again. I think a nice RAID array and a Gigabit ethernet LAN connection would not take too much to re-read from DVD (having 2 or 3 DVD units on the fileserver and one on every machine on the network).
And about the hard drive images, well, I can live without them for a few hours (**knocks on wood**). I already am :)
What I don't like is the rebuild time. Are those 40 hours "offline"? I assume that the filesystem needs to be unmounted. Also, I wonder if "consumer grade" hard drives would take a 40 hour long beating (cooling is not an issue). What were the specs on the machine you used?
Cheers, Hernan