FSCK_EXT2FS(8) OpenBSD System Manager's Manual FSCK_EXT2FS(8)NAMEfsck_ext2fs - Second Extended File System consistency check and
interactive repair
SYNOPSISfsck_ext2fs [-dfnpy] [-b block#] [-m mode] filesystem ...
DESCRIPTIONfsck_ext2fs performs interactive file system consistency checks and
repairs for each of the file systems specified. It is normally invoked
from fsck(8).
The kernel takes care that only a restricted class of innocuous file
system inconsistencies can happen unless hardware or software failures
intervene. These are limited to the following:
Unreferenced inodes
Link counts in inodes too large
Missing blocks in the free map
Blocks in the free map also in files
Counts in the super-block wrong
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
file system on which the correction will take place, and the nature of
the correction. After successfully correcting a file system, fsck_ext2fs
will print the number of files on that file system and the number of used
and free blocks.
If sent a QUIT signal, fsck_ext2fs will finish the file system checks,
then exit with an abnormal return status.
Without the -p option, fsck_ext2fs audits and interactively repairs
inconsistent conditions for file systems. If the file system 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 file system,
fsck_ext2fs will default to a -n action.
The following flags are interpreted by fsck_ext2fs:
-b block#
Use the block specified immediately after the flag as the super
block for the file system. Block 8193 is usually an alternate
super block.
-d Print debugging output.
-f Force checking of file systems. Normally, if a file system is
cleanly unmounted, the kernel will set a ``clean flag'' in the
file system superblock and fsck_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 mode
Use the mode specified in octal as the permission bits to use
when creating the lost+found directory rather than the default
1777. In particular, systems that do not wish to have lost files
accessible by all users on the system should use a more
restrictive set of permissions such as 700.
-n Assume a ``no'' response to all questions asked by fsck_ext2fs
except for ``CONTINUE?'', which is assumed to be affirmative.
File systems will not be opened for writing. This is the default
for file systems to be checked that are concurrently mounted
writable.
-p Specify ``preen'' mode, described above.
-y Assume a ``yes'' response to all questions asked by fsck_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:
1. Blocks claimed more than once by inodes or the free map.
2. Blocks claimed by an inode outside the range of the file system.
3. Incorrect link counts.
4. Size checks:
Directory size not a multiple of file system block size.
Partially truncated file.
5. Bad inode format.
6. Blocks not accounted for anywhere.
7. Directory checks:
File pointing to unallocated inode.
Inode number out of range.
Dot or dot-dot not the first two entries of a directory or
having the wrong inode number.
8. Super Block checks:
More blocks for inodes than there are in the file system.
Bad free block map format.
Total free block and/or free inode count incorrect.
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.
DIAGNOSTICS
The diagnostics produced by fsck_ext2fs are fully enumerated and
explained in Appendix A of Fsck_ffs - The UNIX File System Check Program.
SEE ALSOfs(5), fstab(5), fsck(8), mount_ext2fs(8), rc(8)OpenBSD 4.9 January 10, 2010 OpenBSD 4.9
