NFS tunable parameters

To maximize your system resources, the following NFS tunable parameters can be modified within in the /etc/conf/cf.d/stune file. Do not edit the stune file directly. To change the value of a parameter in the stune file, use the idtune(ADM) command. For information about using idtune to modify parameters in the stune file, see ``Tunable parameters''. You may also want to refer to the idtune(ADM) and stune(DSP) manual pages.

NRNODE

Specifies the maximum number of rnode structures to be allocated for NFS. An rnode is a node specific to the NFS filesystem type. The default is 300 nodes.

NFS_ASYNC_MAX

Specifies the maximum number of Light Weight Processes (LWPs) which can be created for asynchronous I/O over NFS. The default value of 8 LWPs is expected to be sufficient for most systems.

NFS_ASYNC_TIMEOUT

Specifies, in seconds, the time-to-live of the LWPs which do asynchronous I/O over NFS. If an asynchronous request is not generated in the system in NFS_ASYNC_TIMEOUT seconds, the LWPs exit. The default is 4 seconds.

NFS_MMAP_TIMEOUT

Specifies, in seconds, the interval between the time the NFS mmap LWP wakes up and the time the NFS mmap LWP updates file attributes for all mmaped files. The default is 30 seconds. Given the large amount of CPU time the mmap LWP can potentially consume, in cases where a significant number of files have been mmaped over NFS, this value should not be made too small.

NFS_MAXCLIENTS

Specifies the number of active RPC client handles which NFS can cache. The default is 6 clients. Increase this number only when more memory is added to the system.

NFSD_TIMEOUT

Specifies, in seconds, the time-to-live of the LWPs which service NFS requests from clients. If an NFS request is not received by the system in NFSD_TIMEOUT seconds, the LWPs exit. The default is 8 seconds.

NFSD_MAX

Specifies the maximum number of LWPs which can be created for servicing NFS requests from clients. The default is 8 LWPs. Increase this value for dedicated NFS servers.

NFSD_MIN

Specifies the minimum number of LWPs which should always exist in the system for servicing NFS requests from NFS clients. The default is 2 LWPs. Increase this value for dedicated NFS servers.

NFS_RETRIES

Specifies the maximum number of NFS retries before failing the NFS operation for a soft mount. The default is 5 retries. Typically, this value should not be changed.

NFS_TIMEO

Specifies, in seconds, the maximum initial time to wait for an NFS server to respond to a client request. The default is 10 seconds. On machines connected to ``lossy'' networks (networks where packets tend to get lost), this value should be changed. On some ``lossy'' networks you will have greater success getting the packet if you retry earlier; on other networks, you will have greater success if you wait longer.

NFS_NRA

Specifies the number of pages to read ahead for each read operation, if possible. The default is 1 page. Read-ahead over NFS may be turned off by changing this value to 0.