RAID 5 - questions

wesley · 20 Aug 2006 at 13:54

hi guys

i realised i got 2 x SATA 250GB hard drives (spare), i would like to get standalone NAS box but they cost too much and prefer to have 2 in 1 box (winXP for downloading and RAID5 storage)

so i just need 1 x SATA 250GB and RAID 5 controller, this Highpoint Rocket RAID 5 1640 4 port SATA RAID 5 Host Adapter looks good.

got many questions to ask

1. as i understand that RAID 5 need 3 or more hard drives, correct?

2. can those 3 hard drives in different make/model? what about size?

3. this controller card, is it software or hardware? is it important? i'm only use it as storage, that it, not data for 200 PC's at school with AD etc

4. if 3 hard drives, if 1 failed, what happens? cant use access to data till dead hard drive replaced with new one?

5. is it easy to replace dead hard drive? easy to repair RAID 5 array without losing any data?

6. 3 x 250GB RAID 5 = 500GB? can i expand the storage by adding an extra 250GB hard drive to make it 750GB RAID 5? if so, is it possible to keep the data while expanding or lose everything?

7. no build/zero build, what are they?

8. would it's better if winXP in separate hard drive or in the RAID 5 array?

any advice or any tips would be fab

thanks

easyrider · 20 Aug 2006 at 13:58

Here is a thread I started about Raid 5,Should help

wesley · 20 Aug 2006 at 14:06

thanks

so which RAID level did u go for at the end?

wesley · 26 Aug 2006 at 19:24

bump

wesley · 29 Aug 2006 at 09:16

come on!

i really need those questions answered so i can decide to buy RAID 5 contoller or not

thanks

rpstewart · 29 Aug 2006 at 10:39

Sorry, I figured the linked thread would be of use. Anyhoo on with the answers:

1. Yes, it's a 3 drink, I mean drive, minimum

2. Different makes & models are fine, sizes should be but you'll end up with twice the capacity of the smallest one and wasted, inaccessible space on the other(s). Same sizes are best.

3. Not sure, could well be software as there's a link to the 1810 card "for better RAID5 performance" on the Highpoint site. If you can live with 15MB/s write speeds then it'll be fine, if you want more take a look at the 1810.

4. Yeah, you can run quite happily with 1 dead disk but the transfer speeds won't be great as the data has to be rebuilt on the fly.

5. Yeah, remove the duffer and plug in the new disk, the controller will then go away and rebuild the array. You'll be able to continue working but the drives will be heavily utilised so performance will be poor until the array rebuilds.

6. Most cards will support online capacity expansion so you should be able to add another disk without any problems. However this will still leave you with a 500Mb partition in Windows, you'll still need to use Partition Magic to expand the partition into the new space.

7. No idea but I'm guessing it's the ability to build the array on the fly so you don't need to wait 2-3 hours for it to initialise before you can use it.

8. Either is possible, I would be tempted to keep the array just for storage though given the poor write speed.