1E2UNDO(8)                   System Manager's Manual                  E2UNDO(8)
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NAME

6       e2undo - Replay an undo log for an ext2/ext3/ext4 filesystem
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SYNOPSIS

9       e2undo  [  -f  ]  [  -h  ] [ -n ] [ -o offset ] [ -v ] [ -z undo_file ]
10       undo_log device
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DESCRIPTION

13       e2undo will replay the undo log undo_log for an ext2/ext3/ext4 filesys‐
14       tem found on device.  This can be used to undo a failed operation by an
15       e2fsprogs program.
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OPTIONS

18       -f     Normally, e2undo will check the filesystem  superblock  to  make
19              sure the undo log matches with the filesystem on the device.  If
20              they do not match, e2undo will refuse to apply the undo log as a
21              safety mechanism.  The -f option disables this safety mechanism.
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23       -h     Display a usage message.
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25       -n     Dry-run; do not actually write blocks back to the filesystem.
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27       -o offset
28              Specify the filesystem's offset (in bytes) from the beginning of
29              the device or file.
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31       -v     Report which block we're currently replaying.
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33       -z undo_file
34              Before overwriting a file system block, write the  old  contents
35              of  the  block to an undo file.  This undo file can be used with
36              e2undo(8) to restore the old contents of the file system  should
37              something  go  wrong.   If  the  empty  string  is passed as the
38              undo_file argument, the undo file will  be  written  to  a  file
39              named  e2undo-device.e2undo  in  the directory specified via the
40              E2FSPROGS_UNDO_DIR environment variable.
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42              WARNING: The undo file cannot be used to recover from a power or
43              system crash.
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AUTHOR

46       e2undo       was       written      by      Aneesh      Kumar      K.V.
47       (aneesh.kumar@linux.vnet.ibm.com)
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AVAILABILITY

50       e2undo  is  part  of  the  e2fsprogs  package  and  is  available  from
51       http://e2fsprogs.sourceforge.net.
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SEE ALSO

54       mke2fs(8), tune2fs(8)
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59E2fsprogs version 1.44.6          March 2019                         E2UNDO(8)