dual disk mdadm Ubuntu 10.04 LTS

[GeX]

Hi all. I'm restructuring my NAS. It's an HP N36L. Currently has a pair of 1TB Spinpoints in there, and they're getting on a bit so want to setup something more resilient before they start expiring.

It runs Ubuntu server 10.04 LTS. The OS has it's own drive, and the two 1TB drives are just data stores. My original intention was to replace the F1s with 3TB WD Reds and run them mirrored. This prompted me to look into software RAID solutions for Ubuntu (the onboard RAID on the N36L isn't much to write home about).

I found mdadm and have seen that it can create a RAID 5 array using only two disks. This appeals to me as it gives me the option of adding disks to the array at a later date; without having to convert from 1 to 5 (and find interim storage whilst doing so).

Does anyone use mdadm like this. Is it hassle? Is there any risk to my data. What would you do?

 

[GeX]

That's the main reason I want to start the array like this. Can't afford to buy 3 drives, but want the option to grow it if required. What would those usual cautions be?

 

[GeX]

Thanks for the replies guys.

I'm well aware that RAID isn't a backup; I'm not sure I even implied that anywhere in this thread, but people like to chip that in whenever RAID is mentioned it seems!

The NAS' primary purpose is to hold onto backups from other systems, ie Apple TimeMachine backups, mirrors of 'My Documents' on Windows systems etc.

What I may just do is run a pair of 3TB drives mirrored, and the old 1TB mirrored on another array (or connected to something like a pi) and rysnc to that.