chrism at imntv.com wrote: > Joshua Baker-LePain wrote: >> >> You know, the whole "disk is cheap, so why use RAID5?" argument just >> doesn't wash with me. Sure, disk *is* cheap. But some of us need >> every GB we can get for our money (well, given I'm spending grant >> money, it's actually *your* money too (if you live in the US)). >> >> To demonstrate, let's look at a 24 drive system (3ware has a 24 port >> 9650 board). Newegg has 500GB WD RE2 drives for $160. So for $3840 >> in drives I can get: >> >> a) 6TB RAID10 => $0.64/GB >> >> or >> >> b) 10.5TB RAID6 w/ hot spare => $0.37/GB >> >> Umm, I'll take 75% more space for the same money, TYVM. >> did those prices factor in the drive bay infrastructure for 24 drives with cabling, redundant power supplies, etc? > c) 12TB RAID0 w/no redundancy => $0.32/GB > > When my scratch data increases in importance, I'll have to investigate > that new fangled RAID 6 thang. :) Does RAID6 suffer from this > performance degradation bogey man when used with ext3? Isn't RAID6 > just RAID5 with a redundant parity stripe across the drives? btw, I would NOT build a 20-something raid5/6 set. the rebuild times would be massively slow, opening a large window for double drive failure. Before you say 'nah, would never happen', check out phpbb.com, they lost their web server and forums to a double failure last month, and yes, they had a hotspare so the rebuild started immediately. The large SAN vendors usually don't recommend building raid5 sets larger than 6-8 disks, and will stripe or concatenate multiple of those on the typical SAN with 100s of spindles. Myself, I'll stick with RAID10 for anything critical.