Need some raid opinions

[Mellman]

Cliffs: Keep $400 worth of hard drives for a raid 5 array? Or mix and match drives of diff brands you already have?


I recently aquired a Promise SX4000 lite 4 channel IDE raid controller card. My intentions were to use this and run a raid 5 array, using 4 250GB maxtor 16MB cache IDE drives.

I have the 4 drives already, new in box leftover from a client. I also have 6 other 250GB drives, all 8mb cache some maxtor some WD. In the past when i've setup raid arrays i've never mixed and matched drive models in an array. Other then performance is there any other reason to not mix and match drive brands?

Should I sell the 4 new in box maxtors for ~400 on fleabay or use them in a 4 disk raid 5 array?

Feel like this is a stupid question, but looking for a "What would you do" here

 

[Ipno]

Well considering I don't have enough crap to need 750GB of storage... I'd sell them and buy a new video card, but that's me. I guess if you need that much space, go for it.

 

[Matthias99]

I have the 4 drives already, new in box leftover from a client. I also have 6 other 250GB drives, all 8mb cache some maxtor some WD. In the past when i've setup raid arrays i've never mixed and matched drive models in an array. Other then performance is there any other reason to not mix and match drive brands?

Not really. I'm unclear on why it would even be a performance problem (unless you just mean comparing the new 16MB cache drives to the older 8MB cache drives). As long as they're the same size, it should work fine. My only concern would be if some of the drives were heavily used, they could crap out earlier than newer ones.

 

[Mellman]

Originally posted by: Matthias99

I have the 4 drives already, new in box leftover from a client. I also have 6 other 250GB drives, all 8mb cache some maxtor some WD. In the past when i've setup raid arrays i've never mixed and matched drive models in an array. Other then performance is there any other reason to not mix and match drive brands?

Not really. I'm unclear on why it would even be a performance problem (unless you just mean comparing the new 16MB cache drives to the older 8MB cache drives). As long as they're the same size, it should work fine. My only concern would be if some of the drives were heavily used, they could crap out earlier than newer ones.

the 16mb vs 8mb was less of a concern than different read/write speeds on the drives.

And yes i have more than enough need for 750GB, probably am going to need to go back up to my old 3TB amount. I dont throw anything away. So with my old sd camcorder this was less of a problem, now with my HD camcorder its more of an issue. I also have TV series that ive recorded archived (yes, ive gone back and watched them again)

maybe i'll just bite the bullet and setup the new drives - the older drives could crap out sooner, which could be a pain.

now to find me some dinner!

 

[Matthias99]

Originally posted by: Mellman
the 16mb vs 8mb was less of a concern than different read/write speeds on the drives.

There's no guarantee even with the 'same' drives that they'll run in lockstep (seek times, etc. will be different depending on which exact blocks are being accessed). Hell, half the performance benefit of a RAID array is being able to service different read/writes on different drives at the same time. The drives operate completely independently; obviously, if one disk is far slower than the others, it will constrain the speed of the array to some extent, but it should still work as long as the controller/software isn't total crap.

 

[jdkick]

I'm under the impression that arrays should be built with identical drives. I can't offer any technical reasons as to why, but it seems reasonable... equal performance accross the disks, etc. I'd keep the four Maxtor's that are new and sell the other six drives.

As for the controller, will it do the parity calculations for RAID-5 in hardware or does it require a software component still?

 

[Matthias99]

Originally posted by: jdkick
I'm under the impression that arrays should be built with identical drives.

Really, it doesn't matter.

I can't offer any technical reasons as to why, but it seems reasonable...

It's not.

equal performance accross the disks, etc.

As long as they're pretty close in performance, it won't matter. I wouldn't want to mix, say, a 7200RPM drive with 10KRPM ones (or a 5400RPM drive with 7200RPM ones, etc.), but that's only because then it *would* be a performance bottleneck.

As for the controller, will it do the parity calculations for RAID-5 in hardware or does it require a software component still?

The SX4000 is a hardware RAID5 controller. It still requires drivers for Windows to talk to it, but it handles the XOR calculations internally.