System Administration Guide: Network Services

lockd Daemon

This daemon supports record-locking operations on NFS files. The lockd daemon manages RPC connections between the client and the server for the Network Lock Manager (NLM) protocol. The daemon is normally started without any options. You can use three options with this command. See the lockd(1M) man page. These options can either be used from the command line or by editing the appropriate string in /etc/default/nfs. The following are descriptions of keywords that can be set in the /etc/default/nfs file.

Note –

Starting in the Solaris 10 release, the LOCKD_GRACE_PERIOD keyword and the -g option have been deprecated. The deprecated keyword is replaced with the new keyword GRACE_PERIOD. If both keywords are set, the value for GRACE_PERIOD overrides the value for LOCKD_GRACE_PERIOD. See the description of GRACE_PERIOD that follows.

Like LOCKD_GRACE_PERIOD, GRACE_PERIOD=graceperiod in /etc/default/nfs sets the number of seconds after a server reboot that the clients have to reclaim both NFS version 3 locks, provided by NLM, and version 4 locks. Thus, the value for GRACE_PERIOD controls the length of the grace period for lock recovery, for both NFS version 3 and NFS version 4.

The LOCKD_RETRANSMIT_TIMEOUT=timeout parameter in /etc/default/nfs selects the number of seconds to wait before retransmitting a lock request to the remote server. This option affects the NFS client-side service. The default value for timeout is 15 seconds. Decreasing the timeout value can improve response time for NFS clients on a “noisy” network. However, this change can cause additional server load by increasing the frequency of lock requests. The same parameter can be used from the command line by starting the daemon with the -t timeout option.

The LOCKD_SERVERS=nthreads parameter in /etc/default/nfs specifies the maximum number of concurrent threads that the server handles per connection. Base the value for nthreads on the load that is expected on the NFS server. The default value is 20. Each NFS client that uses TCP uses a single connection with the NFS server. Therefore, each client can use a maximum of 20 concurrent threads on the server.

All NFS clients that use UDP share a single connection with the NFS server. Under these conditions, you might have to increase the number of threads that are available for the UDP connection. A minimum calculation would be to allow two threads for each UDP client. However, this number is specific to the workload on the client, so two threads per client might not be sufficient. The disadvantage to using more threads is that when the threads are used, more memory is used on the NFS server. If the threads are never used, however, increasing nthreads has no effect. The same parameter can be used from the command line by starting the daemon with the nthreads option.