"RAID" one disk to a partition on another?

[LosOjos]

I think I just got confused reading this thread!

RAID works at the disk level. The disks do not need to be the same size, but the extra space on larger disks is wasted as only the size of the smallest disk can be used. After the disks have been setup in RAID they can then be partitioned as, as far as the OS is concerned, it is now viewed and treated as 1 physical disk.

What you can't do is set up a RAID with a partition on a non RAID disk, which I think was the OP's original question.

Personally I think the solution to the OP's problem is the /MIR switch using Robocopy.

You got it! That's the problem with trying to express thoughts in terms of actual technologies that don't apply - my fault!

I'll take a look at the /MIR switch, I'm guessing it achieves the same thing as the program Rawns mentioned as in it adds missing files and updates changed ones from one source to a destination? Does it also delete files if you have deleted them from the original location?

[tmcd35]

@LosOjos, The /MIR switch in Robocopy effectively setups the kind of backup/RAID-1 solution you are after. All files on the existing drive are mirrored to the backup drive (whatever size that dive is, can be bigger). When you make changes to files on the original drive they are automatically (so long as the Robocopy is kept running in the background) copied to the backup drive.

[LosOjos]

@LosOjos, The /MIR switch in Robocopy effectively setups the kind of backup/RAID-1 solution you are after. All files on the existing drive are mirrored to the backup drive (whatever size that dive is, can be bigger). When you make changes to files on the original drive they are automatically (so long as the Robocopy is kept running in the background) copied to the backup drive.

Sounds perfect! Thanks

[LosOjos]

Happy to update, I was fortunate enough to receive a small lump of money as a gift this weekend and just now saw Scan had a "Today Only" deal on 2x1TB Seagate Barracuda's (the 64MB cache version) for £98 - ordered them and will be setting them up in RAID, next task is to finally build my NAS using the R-Pi and an external HDD, whenever the money for that materialises in to my life! Thanks for the help all

Though I must say I was quite concerned the order went through at all - they had my old address on file which I didn't realise until I'd placed the order so I had to call them. I didn't actually think Visa payments could be authorised with the wrong address? You learn something new every day!