>From: David Travis <address@hidden>
>Organization: University of Wisconsin-Whitewater
>Keywords: 199901182209.PAA24587 Linux fsck single user
David,
>Thanks for the reply.
>Unfortunately, I can't seem to get past the "fsck" command. When I type
>"fsck" nothing happens. I think I am in single user mode and am putting in
>the password for 'root' but am not getting a response. How can I tell for
>sure if I am in 'root' and/or single user mode? I don't get any list of
>"options" upon reboot as you imply above.
On Linux, you need to give 'fsck' a target file system. Here is the
beginning of the 'fsck' man page on RedHat 5.2 Linux:
FSCK(8) FSCK(8)
NAME
fsck - check and repair a Linux file system
SYNOPSIS
fsck [ -AVRTNP ] [ -s ] [ -t fstype ] [ fs-options ]
filesys [ ... ]
DESCRIPTION
fsck is used to check and optionally repair a Linux file
system. filesys is either the device name (e.g.
/dev/hda1, /dev/sdb2) or the mount point (e.g. /, /usr,
/home) for the file system. If this invocation of fsck
has several filesystems on different physical disk drives
to check, then fsck will try to run them in parallel.
This reduces the total amount time it takes to check all
of the filesystems, since fsck takes advantage of the par-
allelism of multiple disk spindles.
The exit code returned by fsck is the sum of the following
conditions:
0 - No errors
1 - File system errors corrected
2 - System should be rebooted
4 - File system errors left uncorrected
8 - Operational error
16 - Usage or syntax error
128 - Shared library error
The exit code returned when all file systems are checked
using the -A option is the bit-wise OR of the exit codes
for each file system that is checked.
In actuality, fsck is simply a front-end for the various
file system checkers (fsck.fstype) available under Linux.
The file system-specific checker is searched for in /sbin
first, then in /etc/fs and /etc, and finally in the direc-
tories listed in the PATH environment variable. Please
see the file system-specific checker manual pages for fur-
ther details.
OPTIONS
-A Walk through the /etc/fstab file and try to check
all file systems in one run. This option is typi-
cally used from the /etc/rc system initalization
file, instead of multiple commands for checking a
single file system.
-R When checking all file systems with the -A flag,
skip the root file system (in case it's already
mounted read-write).
-T Don't show the title on startup.
-N Don't execute, just show what would be done.
-P When the -A flag is set, check the root filesystem
in parallel with the other filesystems. This is
not the safest thing in the world to do, since if
the root filesystem is in doubt things like the
e2fsck(8) executable might be corrupted! This
option is mainly provided for those sysadmins who
don't want to repartition the root filesystem to be
small and compact (which is really the right solu-
tion).
-s Serialize fsck operations. This is a good idea if
you checking multiple filesystems and the checkers
are in an interactive mode. (Note: e2fsck(8) runs
in an interactive mode by default. To make
e2fsck(8) run in a non-interactive mode, you must
either specify the -p or -a option, if you wish for
errors to be corrected automatically, or the -n
option if you do not.)
-V Produce verbose output, including all file system-
specific commands that are executed.
-t fstype
Specifies the type of file system to be checked.
When the -A flag is specified, only filesystems
that match fstype are checked. If fstype is pre-
fixed with no then only filesystems whose type does
not match fstype are checked.
Normally, the filesystem type is deduced by search-
ing for filesys in the /etc/fstab file and using
the corresponding entry. If the type can not be
deduced, fsck will use the type specified by the -t
option if it specifies a unique filesystem type.
If this type is not available, then the default
file system type (currently ext2) is used.
fs-options
Any options which are not understood by fsck, or
which follow the -- option are treated as file sys-
tem-specific options to be passed to the file sys-
tem-specific checker.
Currently, standardized file system-specific options are
somewhat in flux. Although not guaranteed, the following
options are supported by most file system checkers:
-a Automatically repair the file system without any
questions (use this option with caution). Note
that e2fsck(8) supports -a for backwards compati-
bility only. This option is mapped to e2fsck's -p
option which is safe to use, unlike the -a option
that most file system checkers support.
-r Interactively repair the filesystem (ask for con-
firmations). Note: It is generally a bad idea to
use this option if multiple fsck's are being run in
parallel. Also note that this is e2fsck's default
behavior; it supports this option for backwards
compatibility reasons only.
...
We recommend that you first try:
fsck -A -r
This will go through the file systems listed in /etc/fstab and will ask
you if you want to make repairs when something is found to be bad.
Given that we don't know what is damaged, I would suggest that you
answer 'yes' when asked if you want to make a repair.
>Please forgive me since I'm just a novice at Linux.
No problem.
>By the way, our machine crashed when we had a power outage over New Year's.
>Upon rebooting it came up once and then after a second reboot (and proper
>shutdown) we had this 'fsck' problem. Probably unavoidable...but we are
>planning to buy a backup battery generator pack in case this happens again.
OK. This sounds like the fix will be pretty simple. If you run into
problems you can't figure out, then give Don or I a call:
Tom: 303-497-8642
Don: 303-497-8628
Tom Yoksas
NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publicly available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us.