[SOLVED] Help, How Do I Get Unraid to Rebuilt onto the same disk

[ednigma]

Hello,

 

I am running version 4.7pro with 6 data drives and a parity drive.  I had a disk that SMART was reporting pending sectors.  I copied the data to some free space on another Windows machine and precleared the drive, which cleared the pending sectors (strangely, the reallocated sectors count remained 0).  I put the drive back into the array and booted the server, the array started and showed an unformatted disk.  I thought to myself that unraid just saw the same sonfig, so I stopped the array and unassigned the disk and reassigned the disk, started the array.  The status page still showed the disk as unformatted, so I formatted it and when finished, the array showed the disk as having all its space free, no rebuild.

 

I guess I made a mistake in unassigning the disk and reassigning the disk.

 

Is there as way to force unRaid to rebuild the disk?  I was intending to rebuild the disk and compare it to the data I saved before I precleared it.

 

If not, I can copy the data back, but will the shares just automatically connect?  For example, I noticed that in a DVD share directory, some DVDs seemed split over different disks.  Can i just use for example Teracopy to copy all of the data saved on my Win machine to the Disk 5 share?  For example, do I copy the DVD subdirectory to Disk5, followed by the TV subdirectory, etc?  Will the DVD share directory link back up?  Will the TV share?  I hope I'm making sense.

 

Of course, I'd rather rebuild the data, I hope theres a way to get UnRaid to do it

 

Thanks

[itimpi]

Hello,

 

I am running version 4.7pro with 6 data drives and a parity drive.  I had a disk that SMART was reporting pending sectors.  I copied the data to some free space on another Windows machine and precleared the drive, which cleared the pending sectors (strangely, the reallocated sectors count remained 0).  I put the drive back into the array and booted the server, the array started and showed an unformatted disk.  I thought to myself that unraid just saw the same sonfig, so I stopped the array and unassigned the disk and reassigned the disk, started the array.  The status page still showed the disk as unformatted, so I formatted it and when finished, the array showed the disk as having all its space free, no rebuild.

 

I guess I made a mistake in unassigning the disk and reassigning the disk.

 

Is there as way to force unRaid to rebuild the disk?  I was intending to rebuild the disk and compare it to the data I saved before I precleared it.

 

If not, I can copy the data back, but will the shares just automatically connect?  For example, I noticed that in a DVD share directory, some DVDs seemed split over different disks.  Can i just use for example Teracopy to copy all of the data saved on my Win machine to the Disk 5 share?  For example, do I copy the DVD subdirectory to Disk5, followed by the TV subdirectory, etc?  Will the DVD share directory link back up?  Will the TV share?  I hope I'm making sense.

 

Of course, I'd rather rebuild the data, I hope theres a way to get UnRaid to do it

simply copying the data back to the drive should put everything back as it was.  As long as the folder names are kept the same as they were before then unRAID will realise what share they are part of.

 

It is not that abnormal for a preclear to set pending sectors back to 0, but you want to keep an eye on that drive as any non-zero value for pending sectors can mean that if another disk fails a rebuild of it may not be completely successful. 

 

You do not mention what hardware you have, but if it is up to it I would recommend upgrading to v6 of unRAID (your key remains valid for v6 - in fact the limit for the number of drives increases).  One of the many nice new features of v6 is a notification system that would pro-actively tell you if the important SMART values (e.g. Pending sectors) for any drive change so that the drive should be examined more carefully.  There is a wiki article covering all aspects of upgrading to v6.

[JorgeB]

The mistake you made was formatting the disk, this updated parity so a rebuild won’t work.

 

You could try a rebuild from parity, it would restore all precleared data but disk would still appear formatted, then you'd have to run reiserfsck to try and recover data, but since you have a backup this seams unnecessary.

 

[ednigma]

Thanks for the replies,

 

I should not have been tinkering with the array so early in the AM, but the preclear had just finished and I was hoping the rebuild would finish overnight.

 

@johnnie.black

I see your point that formatting the disk was where I screwed up and a rebuild won't work, but then you go on to say I could try a rebuild from parity that would restore all precleared data.  Could you clarify?  How do I force a rebuild to occur?  I would like to go thru the exercise of running reiserfsck to learn about using it since I've never had to before.

 

Thanks Again..

[JorgeB]

Preclearing writes zeros to all sectors, so all the data in the actual disk is gone, but when you formatted the disk parity was updated with that info only, parity still reflects almost all the data that was on the disk.

 

To force a rebuild you have to stop the array, unassign that disk, start the array, stop again, reassign the disk and start array to begin rebuild.

 

Disk will still rebuild as formatted, but running reiserfsck when the rebuild is complete should get some or with some luck almost all data.

 

https://lime-technology.com/wiki/index.php/Check_Disk_Filesystems#Drives_formatted_with_ReiserFS_using_unRAID_v5_or_later

[ednigma]

Thanks johnnie.black

 

I'll do this and see how much I can recover and compare to my backup, and then mark as solved.

 

Thanks again

[JorgeB]

I'll do this and see how much I can recover and compare to my backup, and then mark as solved.

 

Forgot to say that since the disk has a valid filesystem you should run reiserfsck with --rebuild-tree and -S options, to force fs rebuild and to scan the whole partition, it will take some time.

[ednigma]

@johnnie.black

 

reiserfsck prompted me to rebuild the superblock, so I carefully followed the unRaid FAQ instructions and in the end there were enough data loss, that I decided to shrink the array and rebuild parity in order to upgrade to v6 and then add disk5 back in and restore from backup.

 

Thanks for your help