[
.B \-t
.I fstype
-] [\-\-] [
+]
+.I filesys [ ... ]
+[\-\-] [
.B fsck-options
]
-.I filesys [ ... ]
.SH DESCRIPTION
.B fsck
is used to check and optionally repair a one or more Linux file systems.
.B \-n
option if you do not.)
.TP
-.BI \-t " fstype"
-Specifies the type of file system to be checked. When the
+.BI \-t " fslist"
+Specifies the type(s) of file system to be checked. When the
.B \-A
flag is specified, only filesystems that match
-.I fstype
-are checked. If
-.I fstype
-is prefixed with
-.I no
-then only filesystems whose type does not match
-.I fstype
-are checked.
+.I fslist
+are checked. The
+.I fslist
+parameter is a comma-separated list of filesystems and options
+specifiers. All of the filesystems in this comma-separated list may be
+prefixed by a negation operator
+.RB ' no '
+or
+.RB ' ! ',
+which requests that only those filesystems not listed in
+.I fslist
+will be checked. If all of the filesystems in
+.I fslist
+are not prefixed by a negation operator, then only those filesystems
+listed
+in
+.I fslist
+will be checked.
+.sp
+Options specifiers may be included in the comma separated
+.IR fslist .
+They must have the format
+.BI opts= fs-option\fR,
+and may be prefixed by a negation operator. If an options specifier is
+present, then only filesystems whose
+.B /etc/fstab
+entry do (or do not, if the options specifier was prefixed by a negation
+operator) contain
+.I fs-option
+in their options field of the
+.B /etc/fstab
+file will be checked.
+.sp
+For compatibility with Mandrake distributions whose boot scripts
+depend upon an unauthorized UI change to the
+.B fsck
+program, if a filesystem type of
+.B loop
+is found in
+.IR fslist ,
+it is treated as if
+.B opts=loop
+were specified as an argument to the
+.B \-t
+option.
.sp
Normally, the filesystem type is deduced by searching for
.I filesys
in the
.I /etc/fstab
file and using the corresponding entry.
-If the type can not be deduced,
+If the type can not be deduced, and there is only a single filesystem
+given as an argument to the
+.B \-t
+option,
.B fsck
-will use the type specified by the
-.B \-t
-option if it specifies a unique filesystem type. If this type is not
+will use the specified filesystem type. If this type is not
available, then the default file system type (currently ext2) is used.
.TP
.B \-A
.I fs_passno
(the sixth) field in the
.I /etc/fstab
-file. If there are multiple filesystems with the same pass number,
-e2fsck will attempt to check them in parallel, although it will avoid running
-multiple filesystem checks on the same physical disk. Hence,
-a very common configuration in
+file.
+Filesystems with a
+.I fs_passno
+value of 0 are skipped and are not checked at all. Filesystems with a
+.I fs_passno
+value of greater than zero will be checked in order, with filesystems
+with filesystems with the lowest
+.I fs_passno
+number being checked first.
+If there are multiple filesystems with the same pass number,
+fsck will attempt to check them in parallel, although it will avoid running
+multiple filesystem checks on the same physical disk.
+.sp
+Hence, a very common configuration in
.I /etc/fstab
files is to set the root filesystem to have a
.I fs_passno
.B fsck
to automatically run filesystem checkers in parallel if it is advantageous
to do so. System administrators might choose
-not to use this configuration if they need to avoid multiple filesystem
+not to use this configuration if they need to avoid multiple filesystem
checks running in parallel for some reason --- for example, if the
machine in question is short on memory so that
excessive paging is a concern.
that are executed.
.TP
.B fsck-options
-Any options which are not understood by
-.BR fsck ,
-or which follow the
+Options which which are not understood by
+.B fsck
+are passed to the filesystem-specific checker. These arguments
+.B must
+not take arguments, as there is no
+way for
+.B fsck
+to be able to properly guess which arguments take options and which
+don't.
+.IP
+Options and arguments which follow the
.B \-\-
-option are treated as file system-specific options to be passed to the
+are treated as file system-specific options to be passed to the
file system-specific checker.
+.IP
+Please note that fsck is not
+designed to pass arbitrarily complicated options to filesystem-specific
+checkers. If you're doing something complicated, please just
+execute the filesystem-specific checker directly. If you pass
+.B fsck
+some horribly complicated option and arguments, and it doesn't do
+what you expect,
+.B don't bother reporting it as a bug.
+You're almost certainly doing something that you shouldn't be doing
+with
+.BR fsck.
.PP
Currently, standardized file system-specific options are somewhat in
flux. Although not guaranteed, the following options are supported
reasons only.
.SH AUTHOR
Theodore Ts'o (tytso@mit.edu)
-.PP
-The manual page was shamelessly adapted from David Engel and Fred van
-Kempen's generic
-.B fsck
-front end program, which was in turn shamelessly
-adapted from Remy Card's version for the ext2 file system.
.SH FILES
.IR /etc/fstab .
+.SH ENVIRONMENT VARIABLES
+The
+.B fsck
+program's behavior is affected by the following environment variables:
+.TP
+.B FSCK_FORCE_ALL_PARALLEL
+If this environment variable is set,
+.B fsck
+will attempt to run all of the specified filesystems in parallel,
+regardless of whether the filesystems appear to be on the same
+device. (This is useful for RAID systems or high-end storage systems
+such as those sold by companies such as IBM or EMC.)
+.TP
+.B FSCK_MAX_INST
+This environment variable will limit the maximum number of file system
+checkers that can be running at one time. This allows configurations
+which have a large number of disks to avoid
+.B fsck
+starting too many file system checkers at once, which might overload
+CPU and memory resources available on the system. If this value is
+zero, then an unlimited number of processes can be spawned. This is
+currently the default, but future versions of
+.B fsck
+may attempt to automatically determine how many file system checks can
+be run based on gathering accounting data from the operating system.
+.TP
+.B PATH
+The
+.B PATH
+environment variable is used to find file system checkers. A set of
+system directories are searched first:
+.BR /sbin ,
+.BR /sbin/fs.d ,
+.BR /sbin/fs ,
+.BR /etc/fs ,
+and
+.BR /etc .
+Then the set of directories found in the
+.B PATH
+environment are searched.
+.TP
+.B FSTAB_FILE
+This environment variable allows the system administrator
+to override the standard location of the
+.B /etc/fstab
+file. It is also use for developers who are testing
+.BR fsck .
.SH SEE ALSO
.BR fstab (5),
.BR mkfs (8),
git://git.whamcloud.com / tools / e2fsprogs.git / blobdiff