| FSCK_EXT2FS(8) | System Manager's Manual | FSCK_EXT2FS(8) | 
fsck_ext2fs —
| fsck_ext2fs | [ -dfnpUy] [-bblock#] [-mmode] filesystem ... | 
fsck_ext2fs performs interactive filesystem consistency
  checks and repair for each of the filesystems specified on the command line.
  It is normally invoked from
  fsck(8).
The kernel takes care that only a restricted class of innocuous filesystem inconsistencies can happen unless hardware or software failures intervene. These are limited to the following:
These are the only inconsistencies that
    fsck_ext2fs in “preen” mode (with the
    -p option) will correct; if it encounters other
    inconsistencies, it exits with an abnormal return status. For each corrected
    inconsistency one or more lines will be printed identifying the filesystem
    on which the correction will take place, and the nature of the correction.
    After successfully correcting a filesystem,
    fsck_ext2fs will print the number of files on that
    filesystem and the number of used and free blocks.
If sent a QUIT signal,
    fsck_ext2fs will finish the filesystem checks, then
    exit with an abnormal return status.
Without the -p option,
    fsck_ext2fs audits and interactively repairs
    inconsistent conditions for filesystems. If the filesystem is inconsistent
    the operator is prompted for concurrence before each correction is
    attempted. It should be noted that some of the corrective actions which are
    not correctable under the -p option will result in
    some loss of data. The amount and severity of data lost may be determined
    from the diagnostic output. The default action for each consistency
    correction is to wait for the operator to respond
    yes or no. If the operator
    does not have write permission on the filesystem
    fsck_ext2fs will default to a
    -n action.
The following flags are interpreted by
    fsck_ext2fs.
-b-d-ffsck_ext2fs will not check
      the file system. This option forces fsck_ext2fs to
      check the file system, regardless of the state of the clean flag.-m-nfsck_ext2fs except for
      ‘CONTINUE?’, which is assumed to be
      affirmative; do not open the filesystem for writing.-p-U-yfsck_ext2fs; this should be used with great
      caution as this is a free license to continue after essentially unlimited
      trouble has been encountered.Inconsistencies checked are as follows:
Orphaned files and directories (allocated but unreferenced) are, with the operator's concurrence, reconnected by placing them in the lost+found directory. The name assigned is the inode number. If the lost+found directory does not exist, it is created. If there is insufficient space its size is increased.
Because of inconsistencies between the block device and the buffer cache, the raw device should always be used.
fsck_ext2fs are fully
  enumerated and explained in Appendix A of
  Fsck - The UNIX File System Check
  Program.
fsck_ext2fs utility appeared in
  NetBSD 1.3.
fsck_ext2fs was written by Manuel
  Bouyer
  <bouyer@NetBSD.org>.
| August 27, 2018 | NetBSD 9.4 |