Drive expansion gone wrong

[gustovier]

Hello All,

 

I'm using Unraid 6.5.3  and its where I store all my movies/tv shows.  I recently attempted to upgrade my "Device  7"  from a 5TB Toshiba drive to a 10TB WD.  I've done this operation countless times over the years and this is the first time something has gone wrong.   I shutdown the server, replaced the 5TB toshiba with the 10tb WD and booted up.  Under Main->Array Devices I then selected the 10tb WD to replace the 5TB drive and started the array and let the rebuild process begin.  This is where trouble started and I notice the rebuild running extremely slow <1mb/s and would have taken 1 year to complete.  So I stopped the parity/rebuild, shut down the machine and made sure everything was connected securely thinking it might be a loose sata cable somewhere.  I started back up the machine, For Device 7, selected again the 10tb WD in place of the 5TB drive and started the array to the let the rebuild process begin again. This time I was seeing normal speeds, I let the rebuild process complete over the next 1.75 days.  Once complete the array was up and running but now my Device 7 10tb WD has an "unmountable No File System" message on the main page. Unraid said the filesystem is XFS on this new 10tb WD drive, and I couldn't remember if the original 5tb Toshiba was Reisfs or if it was XFS.   I thought this might be the problem so I stopped the array, tried changing the filesystem to Reisfer and Auto and started the array with no luck. Now, It's almost like the array believes that having disk 7 with "unmountable No File system" is the normal state of things now.    I still have the original 5tb Toshiba drive (which is healthy) and I tried putting that back instead of this new 10tb WD, but now unsaid doesn't recognize it as the original Device 7 in the array and I elected to NOT even start the array in fear that a rebuild/parity process would mess up the contents and I would loose the data.   So now I'm stuck and not sure what to do.  Since I have no idea what was actually on 5TB drive I can't tell if my array with the 10tb drive that's in an "unmountable No File System" state is actually missing the original data that was on the Toshiba 5TB drive.  I guess if I could some how mount it outside the array and check I could find out, but I don't know how to do that.    I'm thinking the best thing right now is to get the array back into a state where device 7 is back to that original Toshiba 5TB drive..but need advice on what the best strategy is here.

 

Thanks everyone for their help!

[Vr2Io]

16 minutes ago, gustovier said:

elected to NOT even start the array in fear that a rebuild/parity process would mess up the contents and I would loose the data.  

Sure don't start the array, otherwise it will rebuild it.

 

18 minutes ago, gustovier said:

I don't know how to do that.

Use unassigned device plugin and mount the disk outside array.

[itimpi]

As well as mounting the original drive via the UD plugin to check it’s file contents (and file system type),:

• check that the file system type for disk7 agrees with what the UD plugin says it was for the 5TB drive.
• start the array in Maintenance mode
• click on drive 7 to bring up the dialog that allows you to check the file system
• run the check and see what it says.   If the drive was XFS this should be relatively quick (minutes) but reiserfs takes much longer (hours).
• if the check above said run without -n try that to start a repair. If prompted to add -L try again with that option
• stop array and then restart in normal mode

ideally after the file system check & repair the disk will be mountable and you can see it’s contents.    You can compare this with what was on the 5TB drive to make sure everything is there.

[gustovier]

Ok, I used the UD plugin and see that all the original Device 7 5TB Toshiba drive contents (I think, I just did a quick check to see if a few of the directories are present) are still part of the array, even though the new 10TB that replaced it is still not mountable.  

 

I also determined The original 5TB drive was XFS.  So I took back out the 5TB and put back in the 10TB and proceeded to correct the filesystem so I ran the xfs_repair -v and I did need to use the -L option.  Once completed the new 10TB disk did mount correctly when I started the array.

 

But now unraid is saying Device 7 with the new 10tb drive(i see an extra 5TB free now)  is being emulated and Parity-Sync/Data-Rebuild process has started over again. Is this normal and I just have to wait for it to complete before the emulation stops?

Edited October 26, 2019 by gustovier

[itimpi]

This is normal in this scenario as you have been swapping drivesaround.  The file system repair has run against the emulated drive as the real drive7 was disabled at this point (I think) or was already needing a rebuild   If you had run the file system repair when the drive is not being emulated then a rebuild would not have been necessary.

[gustovier]

Ok, Also, i do have a few things I want to download using apps hosted on docker in my unraid server and write them to my array shares.  Can I start up my docker apps and do this now or should I really just wait the 2 days its going to take for the rebuild to complete?

[itimpi]

5 minutes ago, gustovier said:

Ok, Also, i do have a few things I want to download using apps hosted on docker in my unraid server and write them to my array shares.  Can I start up my docker apps and do this now or should I really just wait the 2 days its going to take for the rebuild to complete?

The array is usable while a rebuild is going on and any downloads should be reflected in the rebuilt disk if that was where they were sent.   Parity (including the emulated drive) is always updated in real time.   The thing to remember is that any array access is contending for access to the drives with the rebuild process (which is using all array drives) so can have performance impacts.
 

A problem could occur if for any reason things went wrong during the rebuild and you were writing to the array and you lost more drives than you have parity drives.   In such a case it would not be possible to recover without (potentially) losing some of the recent data written to the array.  You need to determine for yourself if this is an acceptable risk.