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SunOS man pages : lockfs (1)

Maintenance Commands                                   lockfs(1M)

NAME

lockfs - change or report file system locks

SYNOPSIS

/usr/sbin/lockfs [ -adefhnuw ] [ -c string ] [ file-system ... ]

DESCRIPTION

lockfs is used to change and report the status of file sys- tem locks. lockfs reports the lock status and unlocks the file systems that were improperly left locked by an applica- tion such as ufsdump(1M). This could occur if ufsdump(1M) is killed using kill(1). Using lockfs to lock a file system is discouraged because this requires extensive knowledge of SunOS internals to be used effectively and correctly. 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 following options are supported. You must be super-user to use any of the following options, with the exception of -a. -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 incon- sistency. 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 Flush all transactions out of the log and write the transactions to the master file system. This option is valid only if logging has been enabled on the file system. SunOS 5.8 Last change: 13 Feb 1998 1 Maintenance Commands lockfs(1M) -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 awak- ens suspended accesses. -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 white spaces.

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: lockfs with the -a option. 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: lockfs with the -w option. SunOS 5.8 Last change: 13 Feb 1998 2 Maintenance Commands lockfs(1M) 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: lockfs with the -u option. The following example shows the lockfs output when the -u option is used to unlock the /var file system and the com- ment 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 attri- butes: ____________________________________________________________ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | |_____________________________|_____________________________| | Availability | SUNWcsu | |_____________________________|_____________________________|

SEE ALSO

kill(1), mount_ufs(1M), ufsdump(1M), fs_ufs(4), attributes(5) , largefile(5) System Administration Guide, Volume 1

DIAGNOSTICS

file system: Not owner You must be root to use this command. file system :Deadlock condition detected/avoided SunOS 5.8 Last change: 13 Feb 1998 3 Maintenance Commands lockfs(1M) 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 5.8 Last change: 13 Feb 1998 4