On Wed, Dec 2, 2009 at 12:59 PM, Christopher G. Stach II <cgs@ldsys.net> wrote:

----- "Ben M." <centos@rivint.com> wrote:

MD RAID. I'd even opt for MD RAID over a lot of hardware implementations. This writeup summarizes a bit of why:

http://jeremy.zawodny.com/blog/archives/008696.html

Hardware RAID's performance is obviously going to be better, but it's only worth it if you *need* it (more than ~8 disks, parity). If you're just doing RAID 0, 1, or 10 in a single box and you're not pushing it to its limits as a DB server or benchmarking and going over it with a magnifying glass, you probably won't notice a difference in performance.

--
Christopher G. Stach II

He had a two drive RAID 1 drives and at least one of them failed but he didn't have any notification software set up to let him know that it had failed. And since that's the case he didn't know if both drives had failed or not. I wonder why he things software RAID would be a) more reliable b) fix itself magically without telling him. He never did say if he was able to use the second disk. I have 75 machines with 3ware controllers and on the very rare occasion that a controller fails you plug in another one and boot up.

I don't use software RAID in any sort of production environment unless it's RAID 0 and I don't care about the data at all. I've also tested the speed between Hardware and Software RAID 5 and no matter how many CPUs you throw at it the hardware will win. Even in the case when a 3ware RAID controller only has one drive plugged in it will beat a single drive plugged into the motherboard if applications are requesting dissimilar data. One stream from an MD0 RAID 0 will be as fast as one stream from a Hardware RAID 0. Multiple streams of dissimilar data will be much faster on the Hardware RAID controller due to controller caching.

Grant McWilliams