[CentOS] Recommendations for a “real RAID" 1 card on Centos box

Mon Mar 10 15:40:45 UTC 2008
nate <centos at linuxpowered.net>

Therese Trudeau wrote:

> Ah great i'll check out the URL thanks.
>  One thing, an earlier poster reccomended RAID 5 instead of RAID 1.
> I guess if one only has 2 drives RAID 1 is the way to go but if I have 4
> drives he said go with
> RAID 5 over RAID 1.  Isn't RAID 1 mirroring a better solution for a 4 drive
> array or am I missing something here?

Depends on your needs, RAID 1 is certainly faster. RAID 1+0 faster
still, but requires more disk(s/space).

Going back to my preferred array vendor, 3PAR, their software/hardware
provides the ability to do online RAID conversions to/from RAID 0, 1+0,
and 5+0 (3+1 parity to 8+1 parity) with no impact to the server. It
also provides the ability to run multiple raid levels on the same
physical disks because the RAID is made up of portions of the disks
(each disk split into 256MB chunks), rather than the full physical disks
themselves. Really flexible/powerful/fast. I love it! On my array I
run RAID 1+0 on the outer regions of the disk(~7% faster than
the inner regions), and RAID 5+0 (8+1) on the inner regions of the

Of course this sort of technology isn't priced for the desktop unless
your doing something like desktop consolidation with virtualization or
remote application hosting/thin client.