different drives in a RAID0?

[Shelnutt2]

Can I use a 60gig Wester digital and a 160gig Maxtor if they are both 7200 RPMs in a RAID0 array? It looks liek I might have to format my hdds due to a virus and I was wondering if I could use IDE raid, with my 2 drives on my PC-DL. If I can is there anything special I need to do in order for windows to detect it as raid? Special drivers?

[bchur83]

Well, if you do, you will end up with a 120GB Raid Array, and wont be able to use the rest of the 160GB Drive. I would advise against RAIDing different size drives.

[Enablingwolf]

There is couple of options for RAID actually.

RAID0 - It will be the size times 2, of the smallest drive, the larger drive excess will be wasted.
RAID1- This is the same as above, but will give you redunacy. No speed benifit.

JDOB- All this will do is make all the drives as one and no benifit but for partitions. JBOD is Just A Bunch Of Disks.

IF you go with a type of RAID then you can go past the drivers on floppy for loading into windows. It is the dreaded F6 to load SCSI/RAID/SATA prior to installing windows

[Shelnutt2]

ok so 2 different size drives is not a good idea. But what about partining the drives into the same partitions, like 20gig partitions? Would it then all work together or is it only single partition that works?

[Baowuf]

Not sure I completely understand your question but if you use only 20gb per drive, the array will only be 40gb. Depending on your raid controller you may or may not be able to use the rest of each drive. If I had to guess, you would probably not be able to access the remaining area. You're probably better off getting a matching 60gb if you want to create an array or just use both drives stand alone if you keep your setup.

[Shelnutt2]

Ok I wasn't sure f I couldn't cheat teh system and have 11x20gig partitions in a RAID0 setup. but I understand now only 1 partition per drive.

[Enablingwolf]

RAID is actually very simple.
If you have 2x 60 gig drives. Put them in RAID0 and they act as one drive(both together equal 120). All writes are on both drives at the same time.

Now if you use odd size drives. IT will equal out to the lowest size drive. It will equal the amount of space out to keep the array in balance. JBOD is the only RAID(not really RAID) type that stops this equalibrium sizing.

Now if you pick RAID1 You are in the same boat as RAID0. You have to keep all the drives equal. Since the array has to be balanced.

Think of it like this. If you have a 60 and a 120 is that equal? Not it is lopsided. The logic of RAID will make it the same. So the smaller drive since it cannnot be a 120 will make the 120, 60.

The only way you can get around having all drives as one drive is JBOD. It will mass all storage into one large drive. Your 120 and 60 will become 180. Then you can split it into whatever you like.

Myself I would find a matching drive or leave it on seperate channels and not RAID it. Unless you need smaller partitions for all your storage. Then JBOD the drives. Thats if your controller supports it. If you want the RAID (1+0) get another sized drive. IF you need the drives to 'carry over' and act as one huge drive then JBOD them.

RAIDx is all about balance.

[Shelnutt2]

RAID is actually very simple.
If you have 2x 60 gig drives. Put them in RAID0 and they act as one drive(both together equal 120). All writes are on both drives at the same time.

Now if you use odd size drives. IT will equal out to the lowest size drive. It will equal the amount of space out to keep the array in balance. JBOD is the only RAID(not really RAID) type that stops this equalibrium sizing.

Now if you pick RAID1 You are in the same boat as RAID0. You have to keep all the drives equal. Since the array has to be balanced.

Think of it like this. If you have a 60 and a 120 is that equal? Not it is lopsided. The logic of RAID will make it the same. So the smaller drive since it cannnot be a 120 will make the 120, 60.

The only way you can get around having all drives as one drive is JBOD. It will mass all storage into one large drive. Your 120 and 60 will become 180. Then you can split it into whatever you like.

Myself I would find a matching drive or leave it on seperate channels and not RAID it. Unless you need smaller partitions for all your storage. Then JBOD the drives. Thats if your controller supports it. If you want the RAID (1+0) get another sized drive. IF you need the drives to 'carry over' and act as one huge drive then JBOD them.

RAIDx is all about balance.


Oh ok, thank you.

You've really cleared up RAID for me. I think I'll stick with 2 separate IDE drives, and no RAID/JBOD(controller doesn't support it) setup.

[matttaylor]

Sorry to burst everyones bubble but you can create a software raid array in windows that will encompus different size and speeds of disks. My server is currently running with 3 10k 8.6gig scsi drives and one 60gig 7200rpm ide drive in a raid o array. It is possible to do this and i have seen no change in performance.

[Shelnutt2]

Sorry to burst everyones bubble but you can create a software raid array in windows that will encompus different size and speeds of disks. My server is currently running with 3 10k 8.6gig scsi drives and one 60gig 7200rpm ide drive in a raid o array. It is possible to do this and i have seen no change in performance.


Really? but is there any performance benifit over jsut 2 seperate IDE drives?

[Enablingwolf]

Is not software RAID basically JBOD then converted to the RAID level chosen through software?

I am drooling over your SCSI. :D

[matttaylor]

I drooled for a while, but youd be suprised how quickly 24 gigs on a server gets filled. No problem though, i have 2 18 gig 10k scsi drives on the way! It's possible that it's jbod, but when i set up the server, i was in a rush and didn't want to wait to d/l the controller drivers.

[Enablingwolf]

I had an older Promise controller and some Quantum Fireballs. It had an odd sized drive and at first it was setup for SCSI and the IDE was doing its own thing. I then went software and it converted everything to JBOD. I was still rather happy though. I took the millisecond, in access times hit for the extra storage.

No matter how fast the drives are, it will only read/write and the slowest drive in the array. 10k drives are darn speedy, but the newer sleek 15k scream! TBH the speedy 7200RPM drives may be slowing your array up.

On a personal note, I am curious on how your access times are hit with the 7200 on the array.

[matttaylor]

Well im sure the fact that the server is an old dell with 288 megs of ram and an old 450 p3 processor running xp pro is holding me back more than the access speed of the drives!
But if needed i can run a test on them. I can't run the scsi's alone right now until i back up the data, but i'd be happy to sandra the suckers if anyone wants me to.