lockfs(1M) System Administration Commands lockfs(1M)NAMElockfs - change or report file system locks
SYNOPSIS
/usr/sbin/lockfs [-adefhnuw] [-c string] [file-system]...
DESCRIPTIONlockfs is used to change and report the status of file system locks.
lockfs reports the lock status and unlocks the file systems that were
improperly left locked.
Using lockfs to lock a file system is discouraged because this requires
extensive knowledge of SunOS internals to be used effectively and cor‐
rectly.
When invoked with no arguments, lockfs lists the UFS file systems that
are locked. If file-system is not specified, and -a is specified,
lockfs is run on all mounted, UFS type file systems.
OPTIONS
The options are mutually exclusive: wndheuf. If you do specify more
than one of these options on a lockfs command line, the utility does
not protest and invokes only the last option specified. In particular,
you cannot specify a flush (-f) and a lock (for example, -w) on the
same command line. However, all locking operations implicitly perform a
flush, so the -f is superfluous when specifying a lock.
You must be super-user to use any of the following options, with the
exception of -a, -f and -v.
The following options are supported.
-a
Apply command to all mounted, UFS type file systems. file-system is
ignored when -a is specified.
-c string
Accept a string that is passed as the comment field. The -c only
takes affect when the lock is being set using the -d, -h, -n, -u,
or -w options.
-d
Delete-lock (dlock) the specified file-system. dlock suspends
access that could remove directory entries.
-e
Error-lock (elock) the specified file-system. elock blocks all
local access to the locked file system and returns EWOULDBLOCK on
all remote access. File systems are elocked by UFS on detection of
internal inconsistency. They may only be unlocked after successful
repair by fsck, which is usually done automatically (see
mount_ufs(1M)). elocked file systems can be unmounted.
-f
Force a synchronous flush of all data that is dirty at the time
fsflush is run to its backing store for the named file system (or
for all file systems.)
It is a more reliable method than using sync(1M) because it does
not return until all possible data has been pushed. In the case of
UFS filesystems with logging enabled, the log is also rolled before
returning. Additional data can be modified by the time fsflush
exits, so using one of the locking options is more likely to be of
general use.
-h
Hard-lock (hlock) the specified file-system. hlock returns an error
on every access to the locked file system, and cannot be unlocked.
hlocked file systems can be unmounted.
-n
Name-lock (nlock) the specified file-system. nlock suspends
accesses that could change or remove existing directories entries.
-u
Unlock (ulock) the specified file-system. ulock awakens suspended
accesses.
-v
Enable verbose output.
-w
Write-lock (wlock) the specified file-system. wlock suspends writes
that would modify the file system. Access times are not kept while
a file system is write-locked.
OPERANDS
The following operands are supported.
file-system
A list of path names separated by whitespace. Note that file-system
can be a directory rather than the specific name of a file system,
such as / or /usr. For example, if you specify /export/home as an
argument to a lockfs command and /export/home is mounted on the
root (/) file system, the lockfs command will take effect on the
root file system.
USAGE
See largefile(5) for the description of the behavior of lockfs when
encountering files greater than or equal to 2 Gbyte ( 2^31 bytes).
EXAMPLES
Example 1 Using lockfs-a
In the following examples, filesystem is the pathname of the mounted-on
directory (mount point). Locktype is one of "write," "name," "delete,"
"hard," or "unlock". When enclosed in parenthesis, the lock is being
set. Comment is a string set by the process that last issued a lock
command.
The following example shows the lockfs output when only the -a option
is specified.
example# /usr/sbin/lockfs -a
Filesystem Locktype Comment
/ unlock
/var unlock
example#
Example 2 Using lockfs-w
The following example shows the lockfs output when the -w option is
used to write lock the /var file system and the comment string is set
using the -c option. The -a option is then specified on a separate
command line.
example# /usr/sbin/lockfs -w -c "lockfs: write lock example" /var
example# /usr/sbin/lockfs -a
Filesystem Locktype Comment
/ unlock
/var write lockfs: write lock example
example#
Example 3 Using lockfs-u
The following example shows the lockfs output when the -u option is
used to unlock the /var file system and the comment string is set using
the -c option.
example# /usr/sbin/lockfs -uc "lockfs: unlock example" /var
example# /usr/sbin/lockfs /var
Filesystem Locktype Comment
/var unlock lockfs: unlock example
example#
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Availability │SUNWcsu │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOkill(1), mount_ufs(1M), sync(1M), attributes(5), largefile(5),
ufs(7FS),
DIAGNOSTICS
file system: Not owner
You must be root to use this command.
file system :Deadlock condition detected/avoided
A file is enabled for accounting or swapping, on file system.
file system: Device busy
Another process is setting the lock on file system.
SunOS 5.10 2 Jan 2008 lockfs(1M)