[CentOS] RAID5 or RAID50 for database?

Thu May 22 16:01:36 UTC 2008
Warren Young <warren at etr-usa.com>

John R Pierce wrote:
> raid50 requires 2 or more raid 5 volumes.
> with 4 disks, thats just not an option.
> for file storage (including backup files from a database), raid5 is
> probably fine... for primary database tablespace storage, I'd only use
> raid1 or raid10.

RAID-10 has only one perfect application, and that's with exactly four 
disks.  It can't use fewer, and the next larger step is 8, where other 
flavors of RAID usually make more sense.  But, for the 4-disk 
configuration, it's unbeatable unless you need capacity more than speed 
and redundancy.  (In that case, you go with RAID-5.)

RAID-10 gives the same redundancy as RAID-50: guaranteed tolerance of a 
single disk lost, and will tolerate a second disk lost at the same time 
if it's in the other half of the RAID.  RAID-10 may also give better 
performance than RAID-50.  I'm not sure because you're trading off more 
spindles against more parity calculation with the RAID-50.  At any rate, 
RAID-10 shouldn't be *slower*.