How to RAID?! i have no clue :(

torN · 20 Mar 2007 at 12:52

Hey guys, I've finally got my dream computer ages ago and everything has been excellent. However im a massive gamer and games nowadays take 1gb to 6gb!

about a week back i noticed that my 120GB WD SATAII drive was getting pretty full and decided it was time to buy another drive. I've bought a WD 160gb SATAII from OcUK and looking to get it running with my 120gb.

However, im really uncertain on how to set up RAID. I understand that raid 0 is fast? And raid 1 is safe? is that right?

I think RAID 0 may be best for me but im unsure. Can you guys help me out with me decision and setup?

thanks

Fr0dders · 20 Mar 2007 at 13:13

RAID works by combining 2 disks together. But they work best with identical capacity.

there are 2 popular forms of RAID. RAID 1 and RAID 0

RAID 1 takes 2 drives (say 2 x 160gb drives) And everything that is written on the first drive, the RAID array copies onto the second. Thus if one of the drive fails, you have an identical copy of the drive to replace it with and loose no data

RAID 0 is faster, and again takes 2 drives (say 2 x 160gb drives) and puts them together to make 320gb. Whenever a file is written, a bit of it is written to one drive, the rest of it to the other. Then, when you have to acces that file, the workload is shared between 2 disks, so its quicker. But if one of the drives fail, they both fail as every file has half of it missing, and no way of recovering the lost information. its less safe, but faster.

The problem comes with the identical drives bit. If you combine a 160gb disk and 120gb disk in a RAID array, the RAID controller can only use the part of the 160gb that matches with the other, ie 120gb. So the other 40gb of your 160gb disk will go unused.

I ideally would think about buying another 160gb Drive. Having a pair of those in RAID, and then having the 120gb Drive to backup important information. So that if the worst does happen and your RAID array breaks, you've still got your important stuff

stu4691 · 20 Mar 2007 at 13:14

Well, you stuffed right from the start. For RAID 0, you need 2 drives that are identical in size (ideally the same model). You can use RAID 1 though, with the second drive as a backup to the first, but your useable diskspace will still be 120GB.

You're right though that RAID 0 is 'fast' and Raid 1 is 'safe'.

torN · 20 Mar 2007 at 14:03

stu4691 said:
Well, you stuffed right from the start. For RAID 0, you need 2 drives that are identical in size (ideally the same model). You can use RAID 1 though, with the second drive as a backup to the first, but your useable diskspace will still be 120GB.

You're right though that RAID 0 is 'fast' and Raid 1 is 'safe'.

****

Dr_Evil · 20 Mar 2007 at 14:06

If you get 2 reliable drives, raid0 is quite safe as well, providing you perform a weekly drive backup.

rpstewart · 20 Mar 2007 at 14:41

stu4691 said:
For RAID 0, you need 2 drives that are identical in size

Not necessarily. The ideal situation is 2 identical drives but you can put two mismatched drives into RAID0.

On a lot of controllers the array will end up as twice the size of the smallest disk but with the Intel Matrix RAID controllers you can RAID partitions rather than just whole drives and therefore the rest of the larger disk becomes available as a separate disk. In all cases mismatched drives will lead to less than optimal performance since the controller will continually have to wait for the slower disk to provide its data before moving on.

crang2k said:
****

No need for that, I'd edit the post before someone takes offence.

torN · 20 Mar 2007 at 15:43

oops sorry.

Ok, so do i have to RAID. Can i not put the new drive in and just use it as storage?

ByteJuggler · 20 Mar 2007 at 16:02

crang2k said:
oops sorry.

Ok, so do i have to RAID. Can i not put the new drive in and just use it as storage?

Of course you don't *have* to RAID. There's nothing stopping your from adding the drive to your PC and having another drive pop up. ;-)

(Of course, if it's not formatted it'd need to be formatted as well.)

stu4691 · 20 Mar 2007 at 17:09

rpstewart said:
Not necessarily. The ideal situation is 2 identical drives but you can put two mismatched drives into RAID0.

My bad. I was under the impression that you always needed 2 drives the same size. Learnt something today