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Raid Striping + Mirroring
Posted: Wed Feb 08, 2006 2:28 pm
by DMB2000uk
Ok, so as I understand it you need identical drives* to stripe**. But do you need identical drives to mirror?
What I really mean is, do they both have to be the same spindle speed? So for example if i have a 7200rpm main 'array' and my mirrored 'array' only runs at 5400rpm will i see a performance loss because of this?
If not this would allow me to have cheaper drives mirroring and say... oh... raptors being used in the array***
I realise the other option is have one raptor for OS and then a second slower big drive for files. But the first option is cooler!
Dan
*OK, identical capacity
**2 drives acting as one, lol, correct me on anything im wrong on
***Im saving up so i can dream right

Posted: Wed Feb 08, 2006 2:47 pm
by Bwall
With most raid controllers you don't need identical drives to stripe. You will just be limited to double the size of the smallest drive in your system. So if you had a 36GB Raptor and a 74GB Raptor your striped array would be 74GB. If you had a 74Gb and a 500GB drive you'd have a 150GB array.
I don't think you need identical drives for mirroring either but again the total disk size will be limited to your smallest drive size. So if you had a pair of 300GB's and a 250GB all the drives in the array would be 250GB.
It's just better use identical drives so you aren't wasting money. I would go with the Raptor as the main drive and then a bigger drive for storage.
Posted: Wed Feb 08, 2006 4:30 pm
by infinitevalence
to do RAID 1+0 you need 4 drives they need to all be the same size.
Honestly if your thinking to do this on your desktop just dont bother, its not much better than just a single drive. and it quadrouples your cost.
Posted: Thu Feb 09, 2006 12:29 am
by pointreyes
The slower spindle drive will slow down the RAID 1.
It's true about drive size, weeellll to a point. My RAID controller breaks that rule. :D I can use various drives sizes and still utilize all the drive space.
e.g. I have had in the past the following setup for the system/program files drives.
Drive 1: 120 GB
Drive 2: 160 GB
Made D1 and D2 be RAID 1 at 120 GB and then took the remaining 40GB on D2 to be a single drive.
Posted: Thu Feb 09, 2006 8:09 am
by DMB2000uk
Ok, so you guys have talked me out of having Raid
Probably to my wallets benifit too!
Though at some point I'm going to have to have a dable, preferably when im earning loads
Dan
Posted: Thu Feb 16, 2006 8:35 pm
by chakhay2000
If ur not committed to AMD, u should give matrix raid of 915 fame a try. It's a great concept that gives u everything from a Raid 1+0 setup but with two drives less...
Posted: Thu Feb 16, 2006 9:06 pm
by FZ1
Do some research on the web before setting up a RAID 0. Unless you use apps that access data from the HDD frequently, it's really not worth it. You are doubling your risk for data loss and seeing only small efficiency gains a small percentage of the time. It's overrated IMHO.