Removing Cache Drive- reboot all unassigned Devices

[Proteus262]

Greetings, I setup an Unraid about a year ago. My use is limited, but its been great, however I was never using the cache drive as I was never in a hurry to transfer files. So I adjusted to just move files directly to the array.  Fast forward. A different system was down so this was a good opportunity to remove the unused cache drive. I followed the steps from a pervious post. Made sure when I did a new config and selected Preserve current assignments Parity and Data. Commited to that and at the main tab the cache drive had been removed. And the Array was there with disk assignments.  Did a shut down and physically removed the drive.  When I booted up, on the main tab all my array devices were Unassigned. Have I lost everything or how can I recover without reformatting the array? I dont remember which drive was assigned to which disk. Any options to recover? Its over 40TB. 

 

I will include them here:

Set EVERY share to Yes. and run the mover. It will take some time. Id recommend shutting any VMs and Dockers down during the process.

When that is done your cache drive should be empty. Set every share to No.

When you are sure the data is off and on the array navigate to Tools > New Config. and you will see a list of hdd's/ssd's with the option to Preserve current assignments: Select everything but your cache drives. (array needs to be stopped to do this)

Web UI should refresh and then you should shutdown if you want to remove the cache drive physically or if not you can now reassign them as you see fit.

4. If you aren't putting in another cache devices then you are good to go if you are you will need to set the shares you want on the cache drive to prefer. That will move the data off the array and back on to the cache drive.

5. When that is done you can change the shares back to what they were originally

 

Thank you for any assistance. 

Proteus

[itimpi]

The instructions you posted left out an important step.    After doing the New Config and making any desired changes you need to start the array at least once to commit the changes.

 

your data will still be intact.    The question to ask at this point is whether you know which drive(s) are parity drives and whether you had 1 or 2.   

[Proteus262]

Face palm.... Son of a... I had one Parity Drive and 5x 10TB drives... But even if I had the disk assignments for the array, it is still wanting to override the data correct? Or does it only overwrite the parity disk?

 

Thank you for the quick response.. 

 

Proteus

[itimpi]

6 minutes ago, Proteus262 said:

Face palm.... Son of a... I had one Parity Drive and 5x 10TB drives... But even if I had the disk assignments for the array, it is still wanting to override the data correct? Or does it only overwrite the parity disk?

 

Thank you for the quick response.. 

 

Proteus

When you assign disks to the array after a New Config then data disks are only over-written if they are not already in Unraid format (and thus the importance of knowing which is the parity drive).   If you are not sure which drive is the parity drive then you can try mounting them in read-only mode from Unassigned Devices.   The parity drive does not have a file system so will not mount, and hopefully all the others mount fine.  With single parity the order of the data disks does not affect parity so after assigning all the disks you can tick the 'parity is valid' option (although I would still run a parity check to make sure).

[Proteus262]

Hey itmpi, that sounds like a great work around. The other thought I had was to get a new drive and assign it as Parity and the rest as disks.  I would have to wait for the new disk to reach parity but then I could see what the others were.

 

Just making sure I understand how to do this. So under the Main tab assign all the disks 1-5 within the Device array.  Start the array and see which drives have file systems correct? I dont see an option for read only mode. Is that automatic when you first start the array? 

 

Thank you again you are a lifesaver of data....

Proteus

[itimpi]

The read-only Mount option is for Unassigned drives - not array drives.   
 

the other approach is:

• assign ALL drives as data drives.
• start array.  A parity drive will always show as unmountable as it has no file system.   Make a note of its serial number.  All data drives should mount ok.   If this is not the case then more work will be needed to identify the parity drive.
• Go to Tools -> New Config and use the option to retain current drive settings (not mandatory but makes things easier)
• return to Main tab and now that you know which drive is parity correct the assignments to reflect this
• start array to commit changes and build parity.
•  

[Proteus262]

Good news, within the terminal a friend and I were able to individually mount the drives to see the file system. So using your previous suggestion, then once we knew which was the parity disk started the array and its currently rebuilding.  Looks to be about a 14-18hr rebuild so fingers crossed everything works out.  But I'm positive its working as it should.

 

Thank you for your help, glad it worked out without any data loss.

 

Proteus.