FSCK_FFS(8) | System Manager's Manual | FSCK_FFS(8) |
fsck_ffs
— Fast
File System consistency check and interactive repair
fsck_ffs |
[-fnpy ] [-b
block#] [-c
level] [-m
mode] filesystem |
fsck_ffs
performs interactive file system
consistency checks and repairs the file system 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:
These are the only inconsistencies that
fsck_ffs
with the -p
option
will correct; if it encounters other inconsistencies, it exits with an
abnormal return status and an automatic reboot will then fail. For each
corrected inconsistency, one or more lines will be printed identifying the
file system on which the correction will take place along with the nature of
the correction. After successfully correcting a file system,
fsck_ffs
will print the number of files on that file
system, the number of used and free blocks, and the percentage of
fragmentation.
If sent a QUIT
signal,
fsck_ffs
will finish the file system checks, then
exit with an abnormal return status that causes an automatic reboot to fail.
This is useful when you want to finish the file system checks during an
automatic reboot, but do not want the machine to come up multiuser after the
checks complete.
If sent an INFO
signal,
fsck_ffs
will print a line to standard error
indicating the name of the device currently being checked, the current phase
number, and phase-specific progress information.
Without the -p
option,
fsck_ffs
audits and interactively repairs
inconsistent conditions for the filesystem. 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_ffs
will
default to a -n
action.
fsck
has more consistency
checks than its predecessors
check,
dcheck,
fcheck,
and
icheck
combined.
The following flags are interpreted by
fsck_ffs
:
-b
block#fsck_ffs
tries to find a valid alternate
superblock based on the information in the disklabel. If that fails, a
number printed by newfs
(using
-N
combined with the original flags used to create
the filesystem) can be used as a value to this argument.-c
level-f
fsck_ffs
will not check the
file system. This option forces fsck_ffs
to check
the file system, regardless of the state of the clean flag.-m
mode-n
fsck_ffs
except for “CONTINUE?”,
which is assumed to be affirmative. The filesystem will not be opened for
writing. This is the default for file systems to be checked that are
concurrently mounted writable.-p
fsck_ffs
will check the
filesystem on the special (raw) device listed on the command line and will
make minor repairs without human intervention. Any major problems will
cause fsck_ffs
to exit with a non-zero exit code,
so as to alert any invoking program or script that human intervention is
required.-y
fsck_ffs
; this should be used with great caution
as this is a free license to continue after essentially unlimited trouble
has been encountered.If neither of the -y
or
-n
options are specified, the user may force
fsck_ffs
to assume an answer of “yes”
to all the remaining questions by replying to a question with a value of
“F”.
In interactive mode, fsck_ffs
will list
the conversion to be made and ask whether the conversion should be done. If
a negative answer is given, no further operations are done on the file
system. In preen mode, the conversion is listed and done if possible without
user interaction. Conversion in preen mode is best used when all the file
systems are being converted at once. The format of a file system can be
determined from the first line of output from
dumpfs(8).
Inconsistencies checked are as follows:
DIRBLKSIZ
.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.
The diagnostics produced by fsck_ffs
are
fully enumerated and explained in Appendix A of
Fsck_ffs - The UNIX File System Check
Program.
fs(5), fstab(5), fsck(8), fsdb(8), growfs(8), mount_ffs(8), newfs(8), rc(8), scan_ffs(8)
September 1, 2016 | OpenBSD-6.8 |