I'm in the planning stages right now to move my current server to unRAID, when I do an upcoming server drive expansion in a few weeks. At the moment I'm reading what I can find and watching YouTube guides. However, I had a question I cannot find a clear answer for in these sources; what is least dangerous way to move data from a RAID array into unRAID? I plan to clean and reuse/add the drives to the unRAID pool, once the data has been transfered. However, the CPU/Mobo/Videocard from the current system will be reused on the unRAID machine as well. So I'm unable to have both systems operational at the same time to do a direct transfer.

 

Would this be as simple as mounting all the drives, new and old, into the new system, setting up unRAID using only the new drives, installing a Linux VM in unRAID, and then mounting the old array in madam to setup the transfer? Then I could unmount the old array, prepare the drives, and add them to the unRAID pool? Would this work?

How much data are we talking about in total?

 

Seems obvious, but in order to do what you want to do you have to have space equal to the size of your used space on the RAID array to copy the data to to set up the unRAID. Here are some options that come to mind:

 

1 - You could backup all of the RAID data to the new drives, and then disassemble the RAID array and use the disks to create an unRAID array. And copy the data from the backup drives onto the previously RAID disks that are now forming the unRAID array. (This results in 2 copies of the data, but might be a good option if you are borrowing some drives, or using excess capacity on existing computers you have, to accomplish the exchange but plan to reclaim all that space once the conversion is complete)

 

2 - Setup an unRAID array in parallel with the RAID setup. I would not want to disturb the RAID configuration for fear of screwing it up and losing data. So I would setup the unRAID server with the new disks, and copy the data from the RAID to the unRAID over the network. I know you said you are reusing the motherboard, but perhaps you have an older computer that you could use for this purpose. Once unRAID is setup using an older motherboard, you could exchange the motherboard.

 

3 - Partition and format the new disks using unRAID. (unRAID is a little persnickety, so make sure you know how to do this or risk wasting a lot of time!)  Copy the data from the RAID array to the unRAID formatted disks, until all of the RAID data is backed up. Depending on platform, you might be able to mount the new disks, 1 or more at a time, into the RAID platform to copy the data over. That would be pretty fast. Once all data is copied, form an unRAID array from the disks you created, which contain all your data, and build parity. Once the data is copied over to the disks, you might have enough confidence to disassemble the RAID array, to repurpose the motherboard for unRAID. But you might want it to be "reconstructable" in case of a big problem.

 

After copying the data, I might suggest some sort of validity check to make sure there is no corruption, before proceeding to the next step. I find md5s work pretty well for this purpose.

It's only about 5TB of data. All the disks are 3TB/ea, of which there are currently three and I'm adding four more of the same size. I hadn't considered option 1, but given the resources that seems the most viable. Thanks for the suggestion.

Edited July 17, 20178 yr by Haffella