ext4magic

ext4magic(8) Administrations Tool ext4magic(8)

NAME

   ext4magic - recover deleted files on ext3/4 filesystems

SYNOPSIS

   ext4magic {-M|-m} [-j <journal_file>] [-d <target_dir>] <filesystem>

   ext4magic [-S|-J|-H|-V|-T] [-x] [-j <journal_file>] [-B n|-I n|-f <file_name>|-i <input_list>] [-t n|[[-a n][-b n]]] [-d <target_dir>] [-R|-r|-L|-l] [-Q] <filesystem>

DESCRIPTION

   The  deletion  of  files  in ext3/4 filesystems can not be easily reversed.  Zero out of the block references in the Inodes makes that impossible.  Experience with other programs have
   proved, it is often possible, to restore sufficient information for a recover of many data files, directly from the filesystem Journal. ext4magic can extract the information from  the
   Journal, and can restore files in entire directory trees, provided that the information in the Journal are sufficient. This tool can recover the most file types, can recover large and
   sparse files, recovered files with original filename, with the original owner an group, the original file mode bits, and also the old atime/mtime stamp.

   The  filesystem  Journal  has a very different purpose, and it will not be possible to recover any file at any time. Many factors affects which data and how long the data store in the
   Journal. Read the ext4magic documentation for more extensive information about the filesystem Journal.

OPTIONS

   Magic Options: These options are for a mulit-stage recover especially for file restore after a recursiv deletion of parts or the whole file system.  (third  step  currently  available
   for ext3 by versions 0.2.x ; a for ext4 is included in version 0.3.x )

   Umount  the  file system directly after an accidentally destroy and use these options with the umount file system or with a copy of this file system.  The program automatically deter
   mines the correct time options if the deletion has only worked a short time (< 5 min) .  For very large deletions, you must use the " after time "

   In the first and second step files restored by copies of inodes.  The third step is trying to restore the remaining files without inode copies. This may take a long time

   -M     Try to recover all files. This option should be used if the entire Filesystem was deleted.

   -m     Try to recover only all deleted files. Use this option with a partially deleted Filesystem.

   Information Options: These options generate generic status information from the filesystem and the Journal.

   -S     Print the filesystem superblock, the option.  -x allows the additional display of content of the group descriptor table.

   -J     Print the content of the Journal superblock.  This option also can used to force loading the Journal. This has a flow control effect in ext4magic with some other options.

   -H     Output a histogram of time stamps from all filesystem Inodes. Allows you to determine the exact time of changes in the filesystem. In connection with a directory name or a  di
          rectory  Inode,  only  the time stamps of this directory tree will be displayed. There are not evaluated any changes, only one per Inode. either the last change or the deletion
          time per Inode arrives to display. If present (ext4), it also create a histogram of create time stamps.

          The optional option -x allows additional a better resolution of the time intervals.

   -V     Print the version of ext4magic and libext2fs

   -T     Display the entire transaction list of all copies of data blocks in the Journal. In conjunction with the -B ; -I and -f , only display the corresponding data  blocks  for  this
          data  . The optional option -x allows an additional transmission time of the transactions, but only if the block is a Inode block. The print is in the same order as the data in
          journal. You can make conclusions from the data received in the Journal.  After the import of backups or after change of timestamps of files, the additional  transmission  time
          will display not always the real transmission time.  If here absolutely incorrect time entries, then check if you using a journal of a read-write open file system.

   -x     controls  optional  the output format and the information content of certain commands. Affects the following options: -S ; -H ; -T ; -B ; -I ; -f ; -L ; -l Detailed description
          see there.

   Selection Options: These options specify the exact files, directories, and data blocks. One hand, they produce specific information, and on the other hand, be used to address the data
   for the Action Options.  ext4magic will accept only one of these options at command.

   -B n   n is the data block number of a filesystem datablock. Without further options it print a "one-byte" hex+ASCII dump from the data block on the filesystem, like the "hexdump  -C"
          command. The optional option -x produced a "four byte" hex+ASCII output.

          With the option -t n it print a copy of the filesystem data block with this transaction number from the Journal.

          # ext4magic /dir/filesystem.iso -B 97 -t 22

          print  a hexdump of the copy from filesystem block number 97, which has been writing to the Journal with the transaction number 22. All copies of a particular data block in the
          Journal and the associated transaction numbers you can find with the optional Option -T

          # ext4magic /dir/filesystem.iso -B 97  -T

          will print a list with all copies of filesystem block number 97 with the transaction numbers. If this data block is a Inode block, print out the exact time for the  transaction
          with the optional option -x

   -I n   n  is  the Inode number. Without any other option, the output is the content of the real filesystem Inode. With a optional -x additional output of a list of all data blocks ad
          dressed by this Inode. If Inode is a directory Inode, the content of the directory entries also printed.

          Together with one of the following option -T ; -J the output is not the content from the real filesystem Inode. The content of all differend Inode copies found in  the  Journal
          are printed.

          with the option -t n only the content of the Inode from transaction " n " are printed.

          the option -I n can also be used in conjunction with the options -L ; -l ; -r or -R (show there)

   -f <filename>
          the  function  is  the same as -I n only here is the <filename> given instead the Inode number. ext4magic search the filesystem to find the Inode number.  The filename can be a
          directory or a filename and must be specified here from the root directory of this filesystem, and not from the root directory of the LINUX system.

          An example: the mount point for this filesystem is " /home " an the filename for Linux is " /home/usr1/Document " you can use now
           # ext4magic /dev/sda3 -f usr1/Document

          The root directory of the filesystem you can use

          -f /
           or

          -f ""
           for ext4magic this is the same.

          you should specify no leading "/" for all other filename. And directory names you should specify without final "/" .

   Expert Options: (new 0.2.1) The optional Expert-Mode must be enabled with the option "--enable-expert-mode" by configure. This makes it possible to open and  recover  front  corrupted
   file  systems.  In the current version it is possible to address backup superblocks and the attempt to recover of the Journal address from the data of the super block, and recover all
   undamaged files after the filesystem was partially damaged or overwritten.

   -s blocksize -n blocknumber
          with this options you can select the backup superblock.  blocksize can be 1024, 2048 or 4096.  blocknumber is the block number of the backup  superblock  this  depends  on  the
          block size. Use the same values as with "fsck" or "debugfs" or use the output of "mkfs -n .."  to determine the correct value.

          Use the options necessarily in the order "-s ... -n ..."

   -c     This will attempt to find the journal using the data of the superblock.  Can help if the first inode blocks of the file system are damaged.

   -D     trying a restore of all files from a badly damaged file system. The combination of all these Expert Options try a file system restore if the superblock broken and the beginning
          of the file system is corrupted or overwritten.  This can only work if e2fsck has not yet changed the faulty file system.

          Example : the first few megabytes of the file system are overwritten. The following tries a copy of all undamaged files of the filesystem. Target directory is "/tmp/recoverdir"

          # ext4magic /dev/sda1 -s 4096 -n 32768 -c -D -d /tmp/recoverdir

   -Q     This  is  a  optional high quality Option for recover and only impact with " -r " and " -R ". Without this option, any valid file name restored from the directories and you can
          set the " before " time stamp to a time in which all files are deleted. So you will find the maximum possible number of files.  It need not necessarily be found  old  directory
          data  blocks  in  the Journal.  However, there are some files found too much. In this mode, re-used file name and reused Inode can not be noticed. As a result some file will be
          created with the extension " "#" or some files created with wrong content. You have to check the files and find bad files and delete itself.

          With option " -Q " works ext4magic more accurately, and can avoid such false and duplicate files. This requires old data blocks of the directories in the Journal. You will  not
          find  of all directories those old blocks in the Journal. Only directories in which files have been previously created or deleted, but not of directories in which no change has
          been a long time. You should set the time stamp " before " immediately before destruction time of the files. Are not sufficient directory  data  available,  may  be,  ext4magic
          can't found deleted files or entire directory content. This option should be used very carefully and will achieve good results only in a few directories.

   Time  Options: With this options you specify a time window at which the program searches for matching time stamps in the Journal data.  ext4magic required for most internaly functions
   two times. A time "after" and a time "before".

   Found Inode only accepted, if not deleted and there time stamp less than "before". If the delete time is less then "after", the Inode are also not used. ext4magic is still  trying  to
   find  for  valid  directory  Inode also a time-matching directory data. For a recover action "before" set to a value at which the data deleted, and "after" set to a value at which the
   data available. Inodes and directory data with other timestamps will be skipped and not used.

   Default, without any time option, ext4magic will search with "now" for the internal time "before", and "now -24 hour" for the internal time "after". If you try to recover without  any
   time option, so you search only over the last 24 hours. If you wait a couple of days before you try to recover deleted data, you must always use time options, or you find nothing

   -a n   with this option you can set the " after " time

   -b n   with this option you can set the " before " time

          n is the number of seconds since 1970-01-01 00:00:00 UTC. This time information can you find in many prints of ext4magic, and you can it produce on the console with the command
          "date" and also insert directly in the ext4magic command line.

          -a $(date -d "-3day" +%s) -b $(date -d "-2day" +%s)

          this example set "after=now-36h" and "before=now-24h"

   -t n   is  an  indirect time option. you can use it with the options -B ; -I ; -f The value n is the transaction number. With this option you can print, list, or recover the data from
          this transaction number.  you can find the transaction numbers with the option -T or in the print of the Inode content.

   File-, IN- and OUT-Options: With these options group, you select the filesystem, and other optional file input and output for control of ext4magic.

   <filesystem>
          selects the filesystem and must always be set.  <filesystem> can be a blockdevice with ext3/4 filesystem, it can also be a uncompressed file image of such a partition.

   -j <journal_file>
          optional you can select a external copy of the Journal file. Without this option, automatically the internal Journal or, if configured, the external Journal on a  block  device
          will used.

   -d <target_dir>
          select  the  output  directory.  There,  the  recovered files were written. If it does not exist, it is created. By default, created files are written to the subdirectory " RE‐
          COVERDIR " in the workpath of the actual shell. This output directory can not be on the same filesystem to be tested filesystem, and should have sufficient space to  write  the
          recovered  files.  The filesystem on this directory should be also ext3/4, otherwise, not LINUX like filesystems generate some errors while writing the file properties.  Either
          you must first changed with the shell in such a suitable filesystem, or you must specify the -d with a target to such a directory

   -i <input_list>
          input_list is a input file. Must contain a list with double-quoted filenames. The files from the list will be restored with option -r or -R

          Blank lines, not cleanly double quoted filenames and all areas before and after " will be ignored.  Such a double-quoted list of file names can create with options -l -x or  -L
          -x by ext4magic and edited by script or by hand.

   Action  Options:  This  option group includes list and recover options. All functions together, they work recursiv controlled by the time options through directory trees. The starting
   point for search is determined by a directory name or a directory Inode number. Default is root of this Filesystem. Matching the time options, the filesystem data, inclusive directory
   data, taken from the Journal. If good data from the file system sections available in Journal, it is possible to see or recover the state of the filesystem at different times.

   -L     Prints the list of all filenames and Inode number of the selected directory tree. Included here also are deleted files and deleted directory trees.  With the additional option.
          -x the file names are printed double-quoted. You can use it for a "Input list" with option -i

   -l     Prints a list of all filenames which have not allocated data blocks. At the beginning of the line are the percentage of unallocated data blocks.  After deletion you  find  here
          all  the  file names you can recover with the Journal data. If you use a very old value for the "before" time, it is possible there are files whose data blocks reused and these
          files in the interim also been deleted. Also included in the list all files without data blocks, symbolic links, empty and other special files.

          Likewise double-quoted file names with optional -x

   -r     applied to directories, all files without conflicts with the occupied blocks will recovered. This are all you can sea with the option -l and be 100% unallocated.  This  options
          only recover deleted files and files without data blocks, in example: symbolic links or empty files.

          The recovered files written to the RECOVERDIR/ This can also set to an alternate <target_dir> with the option -d

          All  files  become the old filename and if possible, also the old file properties. A subdirectory tree can set with "-f dirname" oder "-I inodenumber" If use with a given Inode
          number, the directory name is set to <inodenumber>

          The Time options affect the search. If a file name already exists, or you recover again, it not overwrite files, and a new filename by added a final "#" will created. The maxi‐
          mum ist the extension " ##### " for a filename.

          single files also can recovered, possible search with time-stamps or transaction number.

          (new 0.2.1): Starts this function from the root directory the first stage of the magic functions will follow.

          This starts "lost directory search" and "lost file search" and recovers all the deleted inode that can not be assigned to a file name.  These files you can find in the directo‐
          ries MAGIC-1 and MAGIC-2

   -R     recovers directory tree, is the same as -r

          But two very important differences: Recover of all matched Inodes, even if the blocks allocated, and recover if possible the old directory properties.  Also  empty  directories
          will be restored.  This recovers all deleted and all undeleted files, and it's possible to recover older file versions or directory versions.

          In completely deleted directories the behavior " -R " and " -r " is identical. The difference is there only the complete recover of all directories with option " -R ".  You can
          also restore individual files with time options or a transaction number.

   For all recover cases ACL, SEL and other extended attribute can not recovered in the current version.

   The  output starts at line with a string "--------" before the recovered file name. This is a sign of successful recover. Are not enough permissions to write the recovered files, then
   you will see there some "x" in the string.

   At the end of the process, possibly an issue comes from the hardlink database. A positive number before a file name means : not found all hardlinks to this  file.  A  negative  number
   means  : it created too many hardlinks to this file (possible are, reused filenames or reused Inodes, and so, too many or wrong old filenames for this hardlink. But also possible, all
   files for this hardlink are correct, the time options was not set correct and because of that, the selected inode for the recover was not up to date.  You should check such reports.)

   Re-used data blocks can't realize and so it's possible, it ends in some corrupted files.  Check in any case, all the recoverd files before you use them.

EXAMPLES

   Print the content of a Inode, there are some possibilities.

           # ext4magic /dev/sda3 -f /

           # ext4magic /dev/sda3 -I 2

          the output is the actual filesystem root Inode. In first example input the pathname, second example Inode 2 is also the root directory

           # ext4magic /tmp/filesystem.iso -f / -T -x

          use filesystem image "/tmp/filesystem.iso", search and print all transactions of the Block which included the root Inode, and print all differend Inode. Inclusiv the  blocklist
          off the data blocks. If it's a directory, then print also for each individual Inode the content of the directory.

           # ext4magic /tmp/filesystem.iso -j /tmp/journal.backup -I 8195 -t 182

          Use filesystem image "/tmp/filesystem.iso" and read from external Journal in file "/tmp/journal.backup" and print the content of the Inode number 8195 from the journal transac‐
          tion number 182

           # ext4magic /dev/sda3 -f user1/Documents -a $(date -d "-3 day" +%s) -b $(date -d "-2 day" +%s)

          print a undeleded Inode for pathname "user1/Documents" two to three days back. If it's a directory, then also the content of this directory.  If can not found the old directory
          blocks in Journal, the directory content would be the actual from filesystem.

   Examples of simple Recover

           # ext4magic /dev/sda3 -r -f user1/picture/cim01234.jpg -d /tmp

          Recover  the  file  "/home/user1/picture/cim01234.jpg" which has just been deleted. The file system is mounted normally under "/home".  Note the file path is specified from the
          root directory of the file system and not from the root of the entire Linux system. Whenever possible, umount the file system for the recover.  The  file  will  be  written  as
          "/tmp/user1/picture/cim01234.jpg"

           # ext4magic /dev/sda3 -r

          try to restore all files deleted last 24 hours. Write to directory "./RECOVERDIR/"

           # ext4magic /dev/sda3 -R -a $(date -d "-5day" +%s)

          Attempts to recover all files, even if they are already partially overwritten, recover also all not deleted files.  The erase time is 4 days ago.

           # ext4magic /dev/sda3 -M -d /home/recover

          try multi-stage recover of all files after the filesystem is deleted with a "rm -rf *" . Write the files to "/home/recover". (on ext4 : in this version skipped the last step.)

           # ext4magic /dev/sda3 -RQ -f user1/Dokuments -a 1274210280 -b 1274211280 -d /mnt/testrecover

          try to restore the directory tree "user1/Dokuments/". The "-b" timestamp you must set just before deleting files, the "-a" timestamp prevents found old file versions. This will
          only  work  well, if you've there created or deleted files bevor the "-b" timestamp. Write to the directory "/mnt/testrecover/". If only a few files recovers, attempts the same
          without the option -Q

           # ext4magic /home/filesystem.iso -Lx  -f user1 | grep "jpg" > ./tmpfile

           # ext4magic /home/filesystem.iso -i ./tmpfile -r -d /mnt/testrecover

          try to restore only all deleted files from directory tree "user1/", and have "jpg" in filename. (last 24 hour) and write to "/mnt/testrecover" - use a  temporary  file  "./tmp‐
          file" for a list of filenames.

BUGS

   Direct  use of the Journal of a currently read-write open filesystem produce reading of bad blocks. Such bad blocks provide program errors and false results. You shall therefore never
   use the Journal of such a read-write open file system directly.  Should it be necessary to use a mounted file system, create a copy of the file system journal and used the option -j

AUTHOR

   Roberto Maar

SEE ALSO

   debugfs (8) , e2fsck (8)

version 0.3.2 Oct 2014 ext4magic(8)