lockd.1m (2010 09)

l
lockd(1M) lockd(1M)
NAME
lockd: rpc.lockd - network lock daemon
SYNOPSIS
/usr/sbin/rpc.lockd
[-g graceperiod ][-l
listen_min_backlog][
-t timeout ][nthreads ]
DESCRIPTION
The lockd utility is part of the NFS lock manager, which supports record lock and share lock operations
on NFS files. See fcntl (2) and lockf (2).
lockd provides two functions:
• It forwards
fcntl() locking requests for NFS mounted file systems to the lockd on the NFS
server.
• It generates local file locking operations in response to requests forwarded from
lockd running
on NFS client machines.
State information kept by the lockd about these locking requests can be lost if
lockd is killed or the
operating system is rebooted. Some of this information can be recovered as follows. When a server recov-
ers, it waits for a grace period for all NFS client-site
lockd to submit reclaim requests. Client-site
lockd is notified by the statd
of the server recovery, and promptly resubmits previously granted lock
requests. If a
lockd fails to secure a previously granted lock at the server site, then the
lockd sends a
SIGLOST to the process holding that lock.
Administrators can make changes to the startup parameters for
lockd by logging in as root and editing
the
/etc/default/nfs
file (see nfs (4)). Administrators can also make changes by using the seton-
cenv command.
Options
lockd recognizes the following options and command-line arguments:
-g graceperiod Deprecated in favor of the LOCKD_GRACE_PERIOD
parameter in the NFS
default file, which is equivalent. Specify the number of seconds that all clients
(both NLM and NFSv4) have to reclaim locks after the server reboots. This
option also controls the NFSv4 lease interval. The default value is 90 seconds.
-l listen_min_backlog
Specify the listener backlog, listen_min_backlog, which is the number of connect
requests that are queued and waiting to be processed before new connect
requests begin to get dropped.
-t timeout Specify the number of seconds to wait before retransmitting a lock request to the
remote server. The default value is 5 seconds. Equivalent to the
LOCKD_RETRANSMIT_TIMEOUT
parameter in the NFS default file.
nthreads Specify the maximum number of concurrent threads that the server can handle.
This concurrency is achieved by up to nthreads threads created as needed in the
kernel. nthreads should be based on the load expected on this server. If
nthreads is not specified, the maximum number of concurrent threads will
default to 20. Equivalent to the
LOCKD_SERVERS parameter in the NFS
default file.
Notes
A directory service that provides service name data base support must have the following service entries
in its database:
lockd 4045/udp # NFS lockd daemon/manager for udp
lockd 4045/tcp # NFS lockd daemon/manager for tcp
Kernel Lock Manager logging can be enabled using kctune. By default, the kctune variable
klm_log_level is 0 which disables the Kernel Lock Manager logging feature. The maximum value is
9. The value determines how detailed the log messages are.
AUTHOR
lockd was developed by Sun Microsystems, Inc. and HP.
SEE ALSO
clear_locks(1M), kctune(1M), setoncenv(1M), statd(1M), fcntl(2), lockf(2), signal(2), getservent(3N), nfs(4),
nsswitch.conf(4), services(4).
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1