Raid Questions

Tbid · 20 Sep 2011 at 22:47

I'm interested on attempting to have some safeguard on my data so I'm looking into Raiding some of my drives.

My drives 3 x http://www.overclockers.co.uk/showproduct.php?prodid=HD-366-WD&groupid=701&catid=14&subcat=1279

1 x Hitachi Deskstar 7K3000 2TB

I've identified 2 potential options I could either put the 3 WD drives into RAID 5 or RAID 0+1 With 2 WD drives and the Hitachi drive, I've looked into it and in terms of keeping my data safe Raid 0+1 seems the better option?

Mainly because I have 2 separate types of Drive so the same mechanical failure is very unlikely to affect the whole array.

Which would be the best option to go for performance wise?

Surveyor · 20 Sep 2011 at 23:13

RAID of any description isn't a back up solution.

If the RAID array failed, your PC was stolen or damaged in a fire etc. where's your "back up"?

Answer, it's gone.

Use an external drive to back up your data and keep it stored away from your PC.

Tbid · 20 Sep 2011 at 23:16

Surveyor said:
RAID of any description isn't a back up solution.

If the RAID array failed, your PC was stolen or damaged in a fire etc. where's your "back up"?

Answer, it's gone.

Use an external drive to back up your data and keep it stored away from your PC.

I already have an external backup of my important data but I wish to RAID my data in the event of any of my internal drives failing.

Surveyor · 20 Sep 2011 at 23:26

Tbid said:
I already have an external backup of my important data but I wish to RAID my data in the event of any of my internal drives failing.

Then you're looking for a redundancy solution.

RAID 5 will require a minimum of 3 drives. You'll get a boost in read speed but write speeds take a hit due to the parity calculations. If one drive fails you can replace it and the array can be re-built.

RAID 0+1 (10) requires a minimum of 4 drives. A striped pair mirrored onto another striped pair. You should get a boost in read and write performance. If one drive fails you can replace it and the array can be re-built. In theory the array could survive the failure of 2 drives as long as the remaining 2 drives have all the data.

Some more information here.

Tbid · 20 Sep 2011 at 23:37

Thanks for the info, The thing I'm mainly wondering though is if it'll be possible to RAID 1+0 with 3 Drives, My reasoning is that I can stripe the data across 2 of my 1TB drives then mirror this data with my 2TB drive, is this a viable option?

Surveyor · 20 Sep 2011 at 23:42

Tbid said:
Thanks for the info, The thing I'm mainly wondering though is if it'll be possible to RAID 1+0 with 3 Drives, My reasoning is that I can stripe the data across 2 of my 1TB drives then mirror this data with my 2TB drive, is this a viable option?

Short answer, no.

You can't stripe two 1TB drives and then mirror them on to a 2TB drive.

You need 4 drives for RAID 0+1 (10).

Tbid · 20 Sep 2011 at 23:47

In that case I think I'll RAID 0 - 2 x 1TB drives then back up to my external disk and copy to my internal 2TB drive, would this be the best solution??

Surveyor · 20 Sep 2011 at 23:50

Tbid said:
In that case I think I'll RAID 0 - 2 x 1TB drives then back up to my external disk and copy to my internal 2TB drive, would this be the best solution??

If you set up a RAID 0 with 2x1TB drives, and back them up to an external drive, then also copying the data to the internal 2TB drive seems superfluous.