Table of Contents

SnapRAID - Recover a Lost File

Restore Files

To restore or undelete files to their previous state using the -f, –filter option : 

snapraid fix -f FILE

WARNING: The “fix” command does not differentiate between errors and intentional modifications.

  • It unconditionally reverts the file state as at the last “sync”.

Restore Directories

snapraid fix -f DIR/

Restore Only Missing Files

To recover only accidentally deleted files inside a directory using the -m, –filter-missing option, that restores only missing files, leaving untouched all the others. 

snapraid fix -m -f DIR/

Restore All Deleted Files in All Drives

To recover all the deleted files in all the drives: 

snapraid fix -m

Restore All Deleted Files on Data Disk d1

To recover all the deleted files in a specific data disk: 

snapraid fix -m -d d1

Restore the contents of any specifically named directory in all drives

snapraid fix -m -f Test/

NOTE: This will recreate the contents of any folder named Test anywhere in the array.

Get the absolute path from the file system perspective of any changes since the last sync

Find the absolute path of the file to be recovered. 

snapraid diff --test-fmt path

returns: 

Loading state from /var/snapraid.content...
Comparing...
add /mnt/disk03/Dir1/Subdir1/TVShow1.mkv
add /mnt/disk02/Dir2/Subdir2/TVShow2.mkv
...
update /mnt/disk03/Dir3/Subdir3/TVShow3.mkv
update /mnt/disk03/Dir3/Subdir3/TVShow4.mkv
...
copy /mnt/disk02/Dir4/Subdir4/TVShow5.mkv -> /mnt/disk03/Dir4/Subdir4/TVShow5.mkv
copy /mnt/disk02/Dir4/Subdir4/TVShow6.mkv -> /mnt/disk03/Dir4/Subdir4/TVShow6.mkv
...
move /mnt/disk04/Dir5/Subdir5/TVShow7.mkv -> /mnt/disk04/Dir5/Subdir5x/TVShow7.mkv
move /mnt/disk04/Dir5/Subdir5/TVShow8.mkv -> /mnt/disk04/Dir5/Subdir5x/TVShow8.mkv
...
remove /mnt/disk01/Dir6/Subdir6/TVShow9.mkv
remove /mnt/disk01/Dir6/Subdir6/TVShow10.mkv
...
  550112 equal
     294 added
    1571 removed
       5 updated
       7 moved
    1432 copied
       0 restored
There are differences!

NOTE: The –test-fmt path option returns the absolute file paths instead of relative paths.

Various changes are shown in the example above, including:

  • Add - Some files have been added since the last sync.
  • Update - Some files have been updated since the last sync.
  • Copy - Some files have been copied since the last sync.
  • Move - Some files have been moved since the last sync.
  • Remove - Some files have been removed since the last sync.

Get the data disk from snapraids array perspective of any changes since the last sync

snapraid diff --test-fmt disk

returns: 

Loading state from /var/snapraid.content...
Comparing...
add d3:Dir1/Subdir1/TVShow1.mkv
add d2:Dir2/Subdir2/TVShow2.mkv
...
update d3:Dir3/Subdir3/TVShow3.mkv
update d3:Dir3/Subdir3/TVShow4.mkv
...
copy d2:Dir4/Subdir4/TVShow5.mkv -> d3:Dir4/Subdir4/TVShow5.mkv
copy d2:Dir4/Subdir4/TVShow6.mkv -> d3:Dir4/Subdir4/TVShow6.mkv
...
move d4:Dir5/Subdir5/TVShow7.mkv -> d4:Dir5/Subdir5x/TVShow7.mkv
move d4:Dir5/Subdir5/TVShow8.mkv -> d4:Dir5/Subdir5x/TVShow8.mkv
...
remove d1:Dir6/Subdir6/TVShow9.mkv
remove d1:Dir6/Subdir6/TVShow10.mkv
...
  550112 equal
     294 added
    1571 removed
       5 updated
       7 moved
    1432 copied
       0 restored
There are differences!

NOTE: This returns the actual data disk where some change has occurred since the last sync.

Various changes are shown in the example above, including:

  • Add - Some files have been added since the last sync.
  • Update - Some files have been updated since the last sync.
  • Copy - Some files have been copied since the last sync.
  • Move - Some files have been moved since the last sync.
  • Remove - Some files have been removed since the last sync.

Check if a fix will work

snapraid check -v -m -f "/Dir1/Subdir1/"

returns: 

Self test...
Loading state from /var/snapraid.content...
  551695 files
       0 hardlinks
       0 symlinks
     970 empty dirs
Searching disk d1...
Excluding content '/mnt/disk01/.snapraid.content'
Excluding directory '/mnt/disk01/lost+found' for rule 'exclude /lost+found/'
Searching disk d2...
Excluding directory '/mnt/disk02/lost+found' for rule 'exclude /lost+found/'
Excluding content '/mnt/disk02/.snapraid.content'
...
Selecting...
	/Dir1/Subdir1/
	<missing>
Scanning disk d1...
Scanning disk d2...
...
Using 8981 MiB of memory for the file-system.
Initializing...
Selecting...
Checking...
recoverable Dir1/Subdir1/File1.mkv
recoverable Dir1/Subdir1/File2.mkv
recoverable Dir1/Subdir1/File3.mkv
...
100% completed, 86580 MB accessed in 0:06    

   37633 errors
       0 unrecoverable errors
WARNING! There are errors!

NOTE: This shows that these file are recoverable.

  • Notice that the command used does not use the absolute path, something like /mnt/disk01/Dir1/Subdir1/, but only the relevant path, /Dir1/Subdir1/.
    • Snapraid does not expect you to provide the absolute file system path when fixing files.

Restore the contents of a directory

snapraid fix -m -f "/Dir1/Subdir1/"

returns: 

Self test...
Loading state from /var/snapraid.content...
Searching disk d1...
Searching disk d2...
...
Selecting...
Scanning disk d1...
Scanning disk d2...
...
Using 8981 MiB of memory for the file-system.
Initializing...
Selecting...
Fixing...
recovered Dir1/Subdir1/File1.mkv
recovered Dir1/Subdir1/File2.mkv
recovered Dir1/Subdir1/File3.mkv
100% completed, 86580 MB accessed in 0:06    

   37633 errors
   37633 recovered errors
       0 unrecoverable errors
Everything OK

NOTE: This should recover the directory and files.

  • Notice that the command used does not use the absolute path, something like /mnt/disk01/Dir1/Subdir1/, but only the relevant path, /Dir1/Subdir1/.
    • Snapraid does not expect you to provide the absolute file system path when fixing files.