On 11/16/10 8:31 AM, Benjamin Franz wrote: > In these days of multi-terabyte drives you should be looking at RAID6 > instead. The chances of a 'double failure' during degraded > operation/resync is too high to ignore. These days of cheap drives, I use raid10 almost exclusively. and if its at all mission critical, I like to have 1-2 hotspares. if I was deploying a new server, and its workload was at all database-centric, I'd want to use use 2.5" SAS rather than 3.5" SATA With RAID10, the rebuild time is how long it takes to copy the one drive. if you have 6 drives in a raid10 and one fails, leaving 5, and another fails, there's only a 1 in 5 chance of that other failure being the mirror of the dead drive. If you have a hot spare, that rebuild starts immediately, reducing the window for that dreaded double failure to a minimum.