About to take the plunge

[james25182]

Hi,

 

I'm on the verge of jumping into unRAID but need some help from somebody who has "been there, seen that".

 

I've currently got an Ubuntu server with 3 x 3TB disks using Greyhole on ext4 to keep my media collection. I want to move the data to a new unRAID setup using BTRFS with 1 parity device and the other two devices holding data. I have about 3.5TB of actual media and I'd like to move the drives over somehow. Any suggestions of how to do it?

 

Cheers,

 

James

[jonp]

Do you have new hardware or are you looking to repurpose what you already have?

 

[james25182]

I've got two HP microservers (of different generations) but I've got to reuse the disks.

 

[trurl]

You will have to reformat in unRAID, so you will have to move the data somewhere. Not familiar with greyhole, so don't know how much trouble it will be to free up a drive at a time. You can do unRAID one data disk at a time and do parity last.

[jonp]

Looked up greyhole. So do you have enough capacity between your existing disks to clear one of all its data by moving the files from the disk with the least amount of data to the other two?  If so, you would do that and then add the empty disk to your unRAID server, assign it to disk1 (not parity), let it format, then start copying files from the greyhole server to disk1 on unraid (can do this over network).

 

Then when you've cleared a second disk of all its data and over to disk1 on unRAID, you can add the second disk from greyhole to be your disk2 on unRAID.  Next and final step would be to copy the contents of disk3 on greyhole to disk2 on unRAID.  Then remove disk3 from greyhole and make it the parity disk on unRAID.

 

Make sense?

 

 

[james25182]

Makes perfect sense thanks. I didn't know you could add a parity disk at the end of the process so I now see how this works.

 

Thanks again.

[jonp]

Yup, keep in mind, none of your data will be protected until after the initial parity sync completes. It would be better to start with a new parity disk in the new server, then move this disks over one at a time to keep parity protecting your data throughout the entire process, but if you have backups of your data or are willing to roll the dice, then its really your call.

[garycase]

Agree with JonP => it's far better to do this in a manner that never leaves you with only a single unprotected/un-backed-up copy of your data.

 

With only 3.5GB of actual data, I'd do the following ...

 

(a)  Buy ONE new drive >= 4TB

(b)  Copy ALL of your data to this new drive

©  Now do the process JonP outlined earlier to get all of your data transitioned to UnRAID

(d)  <Optional> Compare the data on your new UnRAID system against the data you backed up to be CERTAIN all went well

(e)  Install the new drive as your UnRAID parity drive ... this will wipe out the data on it; but your server will then be fault-tolerant

[garycase]

After posting that, I realized there's an even better way ...

 

(1)  Generate MD5's for all of your current files  [using either a Linux utility or do it from a Windows box using the excellent Corz checksum utility]

 

(2)  Do steps (a), (b), © above

 

(3)  Validate the MD5's of all the files on the new UnRAID array

 

(4)  Do step (e) above

 

This not only gets all your data moved to a new fault-tolerant server; but you also end up with a complete set of MD5's so you can always validate your data.