XFSCK(1M) INTERACTIVE UNIX System XFSCK(1M)
NAME
xfsck - check and repair XENIX filesystems
SYNOPSIS
/bin/xfsck [options] [filesystem] ...
DESCRIPTION
The xfsck command audits and interactively repairs incon-
sistent conditions for XENIX System V filesystems. If the
filesystem is consistent, then xfsck reports number of
files, number of blocks used, and number of blocks free. If
the filesystem is inconsistent, the user is prompted whether
or not xfsck should proceed with each correction. It should
be noted that most corrective actions result in some loss of
data. The amount and severity of the loss can be determined
from the diagnostic output. If the user does not have write
permission, xfsck defaults to the action of the -n option.
The xfsck options are:
-y Assumes a response to all questions asked by xfsck.
-n Assumes a response to all questions asked by xfsck.
This option does not open the filesystem for writing.
-s b:c
Ignores the actual free list and unconditionally
reconstructs a new one by rewriting the super-block of
the filesystem. The filesystem must be unmounted while
this is done.
This option allows for creating an optimal free-list
organization. The following forms are supported:
-s
-sBlocks-per-cylinder:Blocks-to-skip (filesystem interleave)
If b:c is not given, then the values that were used
when the filesystem was created are used again. If
these values were not specified, then the default
value is used.
-S Conditionally reconstructs the free list. This option
is similar to -s b:c above, except that the free list
is rebuilt only if there are no discrepancies
discovered in the filesystem. The -S option forces a
``no'' response to all questions asked by xfsck. This
option is useful for forcing free-list reorganization
on uncontaminated filesystems.
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-t Causes xfsck to use the next argument as the scratch
file, if needed. A scratch file is used if xfsck can-
not obtain enough memory to keep its tables. Without
the -t flag, xfsck prompts the user for the name of
the scratch file. The file chosen should not be on the
filesystem being checked. In addition, if the scratch
file is not a special file or did not already exist,
it is removed when xfsck completes. Note that if the
system has a large hard disk, there may not be enough
space on another filesystem for the scratch file. In
such cases, if the system has a floppy disk drive, use
a blank, formatted floppy disk in the floppy disk
drive with (for example) /dev/fd0 specified as the
scratch file.
-q Causes xfsck to perform a quiet check. Does not print
size-check messages in Phase 1. Unreferenced fifo5
files are selectively removed. If xfsck requires it,
counts in the superblock are automatically fixed and
the free list salvaged.
-D Checks directories for bad blocks. Use this option
after the system crashes.
-f Causes xfsck to perform a fast check. xfsck checks
block and sizes (Phase 1) and checks the free list
(Phase 5). The free list is reconstructed (Phase 6),
if necessary.
-rr Recovers the root filesystem. The required filesystem
argument must refer to the root filesystem, and
preferably to the block device (normally /dev/root).
This switch implies -y (yes) and overrides -n (no).
If any modifications to the filesystem are required,
the system will be automatically shutdown to ensure
the integrity of the filesystem.
-c Causes any supported filesystem to be converted to the
current filesystem type. The user is prompted to ver-
ify the conversion of each filesystem, unless the -y
option is specified. It is recommended that every
filesystem be checked with this option while unmounted
if it is to be used with the current version of XENIX.
To update the active root filesystem, check it with
the following command line:
xfsck -c -rr /dev/root
If no filesystems are specified, xfsck reads a list of
default filesystems from the /etc/checklist file.
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The following are some of the inconsistencies xfsck checks
for:
- Blocks claimed by more than one inode or the free list
- Blocks claimed by an inode or the free list outside the
range of the filesystem
- Incorrect link counts
- Size checks:
Incorrect number of blocks
Directory size not 16-byte aligned
- Bad inode format
- Blocks not accounted for anywhere
- Directory checks:
File pointing to unallocated inode
Inode number out of range
- Super block checks:
More than 65536 inodes
More blocks for inodes than there are in the filesys-
tem
- Bad free block list format
- Total free block or free inode count incorrect
With the user's consent, xfsck reconnects orphaned (allo-
cated, but unreferenced) files and directories by placing
them in the lost+found directory. The file's (or
directory's) inode number then becomes its name. Note that
the lost+found directory must already exist in the root of
the filesystem being checked and must have empty slots in
which entries can be made. To create the lost+found direc-
tory, copy a few files to the directory, then remove them
(before executing xfsck).
FILES
/etc/checklistContains default list of filesystems to check
/etc/default/bootContains flags for automatic boot control
SEE ALSO
fsck(1M).
NOTES
xfsck will not run on a mounted non-raw filesystem, unless
the filesystem is the root filesystem, or the -n option is
specified and no writing out of the filesystem will take
place. If any such attempt is made, xfsck displays a
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warning and no further processing of the filesystem is done
for the specified device.
WARNINGS
xfsck does not support filesystems created under XENIX-86
version 3.0 because the word order in type long variables
has changed. However, xfsck is capable of auditing and
repairing XENIX version 3.0 filesystems if the word ordering
is correct.
Run xfsck -rr /dev/root for the root filesystem. Run
xfsck /dev/?? on the unmounted block device for all other
filesystems.
It is not recommended that users use xfsck on raw devices.
Although checking a raw device is almost always faster,
there is no way to tell if the filesystem is mounted. If
the filesystem is mounted, cleaning it will almost certainly
result in an inconsistent superblock.
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