Hi all, I was running low on space so I picked up a new 3TB drive and decided to replace it with an existing 1TB drive in the array (disk 3). I cleanly stopped the array and shut the server down. I physically removed the old 1TB drive and installed the new 3TB drive. Once the server booted up I went ahead and added the new drive to the same slot as the old drive and started the array. Once the array started it started to perform a parity rebuild but I also happened to notice that it was telling me I should format this new drive. I ignored this and waited for the parity build to finish which took several hours.

 

I figured after the parity rebuild it would then recover the old data from the 1TB drive and restore it to this new 3TB drive and at the same time I would now have an extra 2TB of space. But now that the parity rebuild is complete the drive is still showing up as unmountable and it still wants me to format this new drive.

 

Why is this happening and what should I do now? I don't want to format it cause I assume I will lose all the data and the parity disk will also be overwritten as well.

 

I still have the old 1TB drive with the data still on it in case I need to reinstall it.

 

What is the correct procedure for replacing as existing smaller drive with a larger drive in the same slot?

 

Old array layout:

Parity: 3TB

Disk 1: 3TB

Disk 2: 3TB

Disk 3: 1TB <-- this is the disk that I intended to replace with a new 3TB disk

Disk 4: 3TB

 

I don't know what you did but I think you will have to start over. New Config with the old disk and all other data disks in their original slots. Don't assign parity. Don't assign the new drive. Start the array and check that you can read files on the old disk.

 

If everything looks OK, stop and assign parity. Don't assign the new drive. Start and let parity build. After parity has finished do a parity check.

 

If everything looks OK, stop and assign the new disk in place of the old disk. The old disk should not be assigned to any slot. Start and unRAID will rebuild onto the new disk.

 

Not sure what you did but your description seemed to be saying you were rebuilding parity and then expecting it to copy the data from the old to the new, which is definitely the wrong procedure.

I removed the old 1TB drive and installed a new 3TB drive and assigned it to the same slot. Then I started the array which automatically invoked a parity which I assume was rebuilding the data from the old 1TB drive onto the new 3TB drive. After that process completed (a few hours), the new drive still shows up as unmountable.

 

I thought that was the correct procedure for replacing a smaller drive with a larger one in the same slot!

... Then I started the array which automatically invoked a parity ...

I don't really understand what you mean by this. Do you mean it automatically started a correcting parity check? What version of unRAID are you running? Before you start the array it should say that starting the array will rebuild the data disk.

Running v6.1.6

 

I'm prob just using the wrong terminology. After starting the array with the 3TB drive in the same slot as the old 1TB drive, it ran "something" which took a few hours to complete. I assume it was restoring the data on to this new drive.

I'm starting over again as you suggested. I reinstalled the old 1TB drive and took the 3TB out. Created a new config and assigned all the drives back to their original slots but left out the parity drive. I started the array and confirmed that all my data was still intact on the 1TB drive. I stopped the array, assigned the parity drive again and started the array. Now it's rebuilding parity from scratch. I'll let this run now for the next few hours then perform a parity check to make sure it's all good.

 

After this is all done, I'll shut the server down again, remove the 1TB drive, re-install the 3TB drive, power-up the server, assign the 3TB drive to the same slot as the old 1TB drive and start the array. This time hopefully it will restore the data back from parity.

It looks like you did the correct procedure, had you run a parity check recently before the upgrade?

Yeah, I have a schedule set to check parity on the first day of every month. Prob best to do another parity check right before making any hard drive changes.

Note that the disk replacement procedure requires that you stop and then start the array between removing the old disk and replacing it with the new disk.

 

Yeah, that's what I did. I had to stop the array and even shut down the server to physically remove the old drive and install a new drive. Not really sure what went wrong but I'm pretty certain I did the right procedure. Oh well, good thing I still kept the old drive handy.

Having removed the old disk you must start the array with the disk missing so that the system thinks the disk has failed.

 

Then stop the array (shutting down if you don't have hot swap drive cages).

 

Now add the replacement disk and restart the array.    It will now rebuild the "failed" drive onto the new replacement.

 

As you didn't do this originally, the new disk was added to the array with the old drive being emulated, rather than replacing the old drive.

Having removed the old disk you must start the array with the disk missing so that the system thinks the disk has failed.

 

Then stop the array (shutting down if you don't have hot swap drive cages).

 

Now add the replacement disk and restart the array.    It will now rebuild the "failed" drive onto the new replacement.

 

As you didn't do this originally, the new disk was added to the array with the old drive being emulated, rather than replacing the old drive.

 

That step is not needed, you just have to shutdown server, replace disk, assign new disk to old slot and start array, rebuild will start.

Da man ... You are correct.  I was getting confused with the procedure to force a rebuild onto the same data disk.