Sql-server – Which SQL files benefit the most from RAID 10 vs RAID 5

Its a personal choice but I like to use RAID 5 for most of my stuff. Is pretty tried and proven and I've always had good experiences when trying to rebuild or recover from it.

Its going to depend a lot on how much space you need, how much speed you need, etc.

Check out this link for more in depth explanation of various RAID levels, etc:

http://decipherinfosys.wordpress.com/2007/01/30/what-raid-is-best-for-you

This link here might actually be a little better:

Selecting the Best RAID Level

EDIT:

Seem to be a lot of people very passionate about RAID 6 and I agree with all of their comments so I figured I'd update my answer to include the following:

In a production environment with that many drives I would choose RAID 6 over RAID 5.

In a home environment with (assuming) non-critical data I suggested RAID 5. Here was my line of thinking:

RAID 6 requires a second set of parity calculations to be made so that data from two failures can be rebuilt.

This additional parity calculation adversely affects write performance. The question is, how much?

Some benchmarks have shown that a RAID controller can suffer more than a 30% drop in overall write performance in RAID 6 compared to a RAID 5 implementation while read performance remains unaffected.

Don't get me wrong, I actually like RAID 6. I'm just not sure its necessary in the scenario described above.

On the flip side... you have a hand-me-down server and (presumably) want to experiment and play with it as if it was a production server. In that case... let's treat it like one and go with RAID 6.

One other thing I failed to mention in my original answer which I should have addressed is your other two operating system drives. I would recommend you MIRROR those two and put the six drives in either RAID 5 or RAID 6.

The choice is totally up to you as to whether you want the extra parity drive or not.

I hope this satisfies everybody. :-)

Hands down if you needs lots of I/O you need to look at raid 10

RAID 1+0 (or 10) is a mirrored data set (RAID 1) which is then striped (RAID 0), hence the "1+0" name. A RAID 1+0 array requires a minimum of four drives: two mirrored drives to hold half of the striped data, plus another two mirrored for the other half of the data. In Linux MD RAID 10 is a non-nested RAID type like RAID 1, that only requires a minimum of two drives, and may give read performance on the level of RAID 0.