On 04/11/2013 11:36 AM, m.roth at 5-cent.us wrote: > I'm setting up this huge RAID 6 box. I've always thought of hot spares, > but I'm reading things that are comparing RAID 5 with a hot spare to RAID > 6, implying that the latter doesn't need one. I *certainly* have enough > drives to spare in this RAID box: 42 of 'em, so two questions: should I > assign one or more hot spares, and, if so, how many? > > mark I was building a home NAS over the holidays and had the same question (well, not hot spare, but 5 vs. 6). A good friend on mine pointed me to the following article; http://www.zdnet.com/blog/storage/why-raid-5-stops-working-in-2009/162 I was using 6x 3 TB drives, so I decided to opt for RAID 6. About a month ago, a drive cacked out and I was *very* relieved to know that I was covered until I replaced the disk and it finished rebuilding. If you have 42 disks, I'd not even think twice and I would use RAID level 6. If fact, with such a large number, I'd almost be tempted to break it into two separate RAID level 6 arrays and use something like LVM to pool their space, just to hedge my bets. -- Digimer Papers and Projects: https://alteeve.ca/w/ What if the cure for cancer is trapped in the mind of a person without access to education?