Disk rebuild lost data

[naxiand]

So, after I stopped my array my disk 3 red balled. Checked cables all ok. Started again I go to  maintenance mode I run fsck check, it completes without errors, so not corruption.  Start the array normal missing disk 3. Stop start and data rebuild starts also. It finishes OK, all my data are there (look first diagnosis) . The moment I try to write again to disk (I think this was the time) redballed again.

This time since I want to move to xfs filesystem the disk is formatted to xfs and disk rebuild starts again.

When it finishes drive till now seems ok but my data is gone. (look second diagnosis). So almost 8 hours of data rebuild and not data at all on my drive. Any idea what happened?

tower-diagnostics-20160221-1134.zip

tower-diagnostics-20160221-2041.zip

[itimpi]

So, after I stopped my array my disk 3 red balled. Checked cables allow ok. Started again I gotta maintenance mode I run fsck check, it completes without errors, so not corruption? Start the array normal missing disk 3. Stop start and data rebuild starts also. It finishes OK, all my data are there (look first diagnosis) . The moment I try to write again to disk (I think this was the time) redballed again.

This time since I want two move to xfs filesystem the disk is formatted to xfs and disk rebuild starts again.

When it finishes drive till now seems ok but my data is gone. (look second diagnosis). So almost 8 hours of data rebuild and not data at all on my drive. Any idea what happened?

You did not try and change the format of the existing disk 3 did you?  You cannot do that and keep the data on it intact.  If you did try that did you hit the format button (I hope not as doing a format wipes any existing data)?  If not then changing it back might make the original data visible again.

[Squid]

This time since I want two move to xfs filesystem the disk is formatted to xfs and disk rebuild starts again.

The key thing here is  ^^^^^

 

unRaid is no different than any other OS....  You formatted the disk (in this case the emulated drive) and then rebuilt.  This is no different than telling Windows that you want to format your second hard drive and then expecting there to be data still on it.

 

 

 

[naxiand]

I will try this, but yes I have pushed yes to format the drive knowing the data will be lost and knowing that after disk rebuild the data should come back from parity drive or not?

[itimpi]

I will try this, but yes I have pushed yes to format the drive knowing the data will be lost and knowing that after disk rebuild the data should come back from parity drive or not?

No - that is not how parity works (you should read the unRAID wiki on this).  There is no data in the sense you are thinking on the parity drive - just the information required to reconstitute any particular sector on a failed disk by using the combination of the parity disk plus all the other good data disks.  A rebuild never changes the format of a disk - it just puts things back exactly as they were before the disk failed.

 

When you formatted disk3 you also updated parity in line with the format.  At this point your only easy  recourse is to recover the data from a backup.  Having said that reiserfs is quite good at recovering from extreme corruption (which is what doing a format effectively is) and getting back most of the data.

[JorgeB]

Since it was rfs you have a good chance of recovering most of your data.

 

Change fs on disk back to reiser, start array in maintenance mode and type:

 

reiserfsck --rebuild-tree -S /dev/md3

[itimpi]

Since it was rfs you have a good chance of recovering most of your data.

 

Change fs on disk back to reiser, start array in maintenance mode and type:

 

reiserfsck --rebuild-tree -S /dev/md3

Is that sufficient?  Do you have to include the --scan-whole-partition option as well?

[JorgeB]

-S scans the hole partition, if it asks to rebuild the superblock follow the wiki instructions:

 

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

[JorgeB]

Good luck, reiserfsck is very good at doing its thing, I once formatted a disk full of video files on purpose and it recovered all files, only one failed checksum but it was still playable.

[naxiand]

I went back to riserfs but disk is redballed now. https://www.dropbox.com/s/y8c2x3bw83fkmth/Screenshot_2016-02-21-21-13-13.png?dl=0

So how I proceed? (All previous disks that had problems where Samsung also)

I attach new diagnosis after went back to riserfs

 

 

Edit :stopped the array to go to maintenance mode disk 3 is nowhere to be found.. Is reboot an option that might do it reappear and proceed with rebuild? And yes disk 3 has only 300 video files.

tower-diagnostics-20160221-2113.zip

[itimpi]

I went back to riserfs but disk is redballed now. https://www.dropbox.com/s/y8c2x3bw83fkmth/Screenshot_2016-02-21-21-13-13.png?dl=0

So how I proceed? (All previous disks that had problems where Samsung also)

I attended new diagnosis after went back to riserfs

You can remove the physical drive and then run the reiserfsck against the emulated drive

[JorgeB]

If you have a spare you can rebuild first and then run reiserfsck, or you can rebuild after running it on the emulated disk, it will probably take longer on the emulated disk, either way I would not use the original disk, as it has redballed twice.

 

I have many of those Samsung disks working fine on v6, although they are not the most reliable.

[naxiand]

If you have a spare you can rebuild first and then run reiserfsck, or you can rebuild after running it on the emulated disk, it will probably take longer on the emulated disk, either way I would not use the original disk, as it has redballed twice.

 

I have many of those Samsung disks working fine on v6, although they are not the most reliable.

 

 

i will have a spare seagate 5tb in two days. for the moment since the disk wasnt visible anymore i just rebooted server (i have always checked not to start automatically the array). now i cant go in maintance mode because unraid sees disk3(samsung) as new drive and wants to start rebuild.

If i understand correct since last rebuild drive came empty with xfs filesystem and now went back to riserfs hopping to recover with fsck if i start now disk rebuild procedure from parity will lost any chance to recover .

so how i can run  reiserfsck --rebuild-tree -S /dev/md3 if not in maintance mode?

[JorgeB]

i will have a spare seagate 5tb in two days. for the moment since the disk wasnt visible anymore i just rebooted server (i have always checked not to start automatically the array). now i cant go in maintance mode because unraid sees disk3(samsung) as new drive and wants to start rebuild.

If i understand correct since last rebuild drive came empty with xfs filesystem and now went back to riserfs hopping to recover with fsck if i start now disk rebuild procedure from parity will lost any chance to recover .

so how i can run  reiserfsck --rebuild-tree -S /dev/md3 if not in maintance mode?

 

Select no device for disk3 on the drop down menu, and start in maintenance mode.

[JorgeB]

Also, you could rebuild again, the chance of recovery is the same, but since you don't have a spare I believe it's not a good idea to re-use old disk.

[naxiand]

i will have a spare seagate 5tb in two days. for the moment since the disk wasnt visible anymore i just rebooted server (i have always checked not to start automatically the array). now i cant go in maintance mode because unraid sees disk3(samsung) as new drive and wants to start rebuild.

If i understand correct since last rebuild drive came empty with xfs filesystem and now went back to riserfs hopping to recover with fsck if i start now disk rebuild procedure from parity will lost any chance to recover .

so how i can run  reiserfsck --rebuild-tree -S /dev/md3 if not in maintance mode?

 

Select no device for disk3 on the drop down menu, and start in maintenance mode.

 

where is current pending sector ,value , worst when is reiserfs is 100 but when i was with xfs was 250 all or at least one of those values and wasnt colored

thank you so now the command will be reiserfsck --rebuild-tree -S /dev/Sdn  ?

https://www.dropbox.com/s/rb0gms71gu479p6/1.JPG?dl=0

https://www.dropbox.com/s/l01dc0po0e0daz7/2.JPG?dl=0

[JorgeB]

 

thank you so now the command will be reiserfsck --rebuild-tree -S /dev/Sdn  ?

 

reiserfsck --rebuild-tree -S /dev/md3

[naxiand]

 

thank you so now the command will be reiserfsck --rebuild-tree -S /dev/Sdn  ?

 

reiserfsck --rebuild-tree -S /dev/md3

 

 

Sure? have you seen the screenshots drive 3 is labeled as no device . Just want to recover files if any and i will replace drive in 2 days with new one

 

[JorgeB]

Sure? have you seen the screenshots drive 3 is labeled as no device

(just want to recover files and in 2 days that i will have a spare i will copy the recovered files-if any to new drive and then take out the samsung)

 

You'll be running reiserfsck on the "emulated" disk3, unraid will use all other disks + parity to do it.

 

 

[naxiand]

Sure? have you seen the screenshots drive 3 is labeled as no device

(just want to recover files and in 2 days that i will have a spare i will copy the recovered files-if any to new drive and then take out the samsung)

 

You'll be running reiserfsck on the "emulated" disk3, unraid will use all other disks + parity to do it.

 

 

ok supossed when finished on emulate recovers everything then what?When rebuild has started and drive was with xfs filesytem came with no data. so there is no hope to run reiserfsck on the physical drive where changes seems better since i havent made any writes to drive after the format.

[JorgeB]

Whatever you recover on the emulated disk will be rebuilt on the spare, when you get it, it will always be rebuilt as reiserfs.

 

You could also try it on the old disk and then copy data to a new one, but since that disk has pending sectors there's less chance of recovering everything.

[naxiand]

Whatever you recover on the emulated disk will be rebuilt on the spare, when you get it, it will always be rebuilt as reiserfs.

 

 

Thanks I am an old unraid user i have read the wiki more than once but propably not enough for version 6. If i want to migrate to xfs slowly my option is that i add new drive to array in xfs filesystem copy over all files from disk with resierfs filesystem, then stop array press new config and take out the drive with reiserfs, assign again the rest of the drives , start array again. Is this the way ?

[JorgeB]

Thanks I am an old unraid user i have read the wiki more than once but propably not enough for version 6. If i want to migrate to xfs slowly my option is that i add new drive to array in xfs filesystem copy over all files from disk with resierfs filesystem, then stop array press new config and take out the drive with reiserfs, assign again the rest of the drives , start array again. Is this the way ?

 

Format XFS on replacement drive / Convert from RFS to XFS

[trurl]

Just thought I would chime in with a better way to think about "formatting" in case it helps you better understand what you did wrong, or helps others who may read this thread.

 

Format means write an empty filesystem to this disk. That is what it has always meant in every operating system you have ever used. unRAID treats this write just like any other and updates parity, so a rebuild after that will just rebuild the empty filesystem, as you experienced.

[naxiand]

Just thought I would chime in with a better way to think about "formatting" in case it helps you better understand what you did wrong, or helps others who may read this thread.

 

Format means write an empty filesystem to this disk. That is what it has always meant in every operating system you have ever used. unRAID treats this write just like any other and updates parity, so a rebuild after that will just rebuild the empty filesystem, as you experienced.

 

 

Yes i understand this completely. What was wrong from my side was that after i formatted the disk to xfs and i have been informed that parity dont care about filesystem, that my disk will be rebuild from parity. This was my mistake...

 

 

Just an update after i have format disk3 to xfs data rebuild ,since this was a mistake i have formatted back to reiserfs and runned(at the moment is at pass3 and i see that starts to recover my files one by one.finger crossed i will inform about result and how to proceed )  reiserfsck --rebuild-tree -S /dev/md3