Raid 5 question

nightrider1470 · 8 Oct 2013 at 13:25

I have just bought a 5 bay hard drive enclosure and plan to use Raid 5. My question is can I install 2 drives say then just keep adding drives when I want? or will I need to install all 5 hard drives at once?

Thanks!

rpstewart · 8 Oct 2013 at 13:30

Raid5 needs 3 disk as a minimum. Whether you can do an online expansion will be down to your controller, some can do it some can't

nightrider1470 · 8 Oct 2013 at 13:54

Can you mix the drives? This is the enclosure here http://www.sharkoon.com/?q=en/node/1809

cyber69 · 8 Oct 2013 at 19:20

You may be able to mix the drive manufacturers but not the size of the drive's unless they are to be in different raid groups.

Make sure you've got a backup plan for a 5 disk raid5 set. I've had a couple of instances whereby one drive fails and when replaced the raid does not rebuild properly.

Raid 6 is better as it allows a 2 drive failure but at a loss of space.

I bought a 4 bay Synology unit and installed 3 x 3TB drives in it but I do have a 4th 3TB spare to either expand the storage or as an emergency swap out drive.

I back this up to a Lacie Quadra 3TB esata unit which is excellent.

nightrider1470 · 9 Oct 2013 at 15:24

On the back of my raid enclosure it has raid options. Am confused to what the combine switch does? - Bottom right on pick!

is it possible to have it setup with 4 x 4TB drives 2 drives mirroring each other?

cyber69 · 10 Oct 2013 at 14:59

I'd suggest the combine might be classed as JBOD or where each disk is seperate?

A solution whereby you are mirroring a pair of disk would be classed as raid 0 + 1, where a pair of striped disks are mirrored to a second pair.

I'd go for a 4 disk raid 5 but back it up regulary using the esata port onto a pair of 4TB disks for total data security. You can do incremental backups to those drives to minimise backup time.