nfso Command

AIX Version 4.3 Commands Reference, Volume 4

nfso Command

Purpose

Configures Network File System (NFS) network variables.

Syntax

nfso { -a | -d Option | -l HostName | -o Option [ =NewValue ] } [ -c ]

Description

Attention: Be careful when you use this command. The nfso command performs no range checking; therefore, it accepts all values for the variables. If used incorrectly, the nfso command can make your system inoperable.

Flags

-a	Prints a list of all configurable options and their current values.
-c	Changes the output format of the nfso command to colon-delineated format.
-d Option	Sets the Option variable back to its default value.
-l HostName	Allows a system administrator to release NFS file locks on an NFS server. The HostName variable specifies the host name of the NFS client that has file locks held at the NFS server. The nfso -l command makes a remote procedure call to the NFS server's rpc.lockd network lock manager to request the release of the file locks held by the HostName NFS client. If there is an NFS client that has file locks held at the NFS server and this client has been disconnected from the network and cannot be recovered, the nfso -l command can be used to release those locks so that other NFS clients can obtain similar file locks for their purposes. Note: The nfso command can be used to release locks on the local NFS server only.
-o Option[ =NewValue ]	Shows the value of the option specified by the Option variable if the NewValue variable is not specified. If a new value is specified, the Option variable is set to that value. The nfso command sets or displays network options in the kernel. This command operates only on the kernel currently running. Use the nfso command after each system startup or network configuration. The effect of changing any value will be immediate unless noted in the description of the option.

Options

nfs_gather_threshold	Determines when to attempt to gather write requests to a file. If the size of the NFS write request is less than the value of the nfs_gather_threshold option, the NFS server writes the data and immediately responds to the NFS client. If the size of the NFS write request is equal to or greater than the value of this option, the NFS server writes the data and waits for a small amount of time before responding to the NFS client.
nfs_repeat_messages	Checks for duplicate NFS messages. This option is used to avoid displaying duplicate NFS messages. When set to a value of 1, all NFS messages are printed to the screen. If set to a value of 0, duplicate messages appearing one after the other are not printed to the screen. Only the first message of such a sequence is displayed. When a different message appears, a message will be displayed similar to: Last NFS message repeated n times.
nfs_socketsize	Sets the queue size of the NFS server UDP (User Datagram Protocol) socket. This socket is used for receiving the NFS client requests and can be adjusted so that the NFS server is less likely to drop packets under heavy load. The value of the nfs_socketsize variable must be less than the sb_max option, which can be manipulated by the no command. The nfso command sets or displays network options in the kernel. This command operates only on the currently running kernel. The nfso command must be run after each system startup or network reconfiguration. In order for the option values to take effect, you must first stop and restart NFS (Network File System) using the following commands: stopsrc -s nfsd startsrc -s nfsd
portcheck	Checks whether an NFS request originated from a privileged port. The default value of 0 disables the port checking that is done by the NFS server. A value of 1 directs the NFS server to do port checking on the incoming NFS requests.
udpchecksum	Performs the checksum of NFS UDP packets. The default value of 1 directs the NFS server or client to build UDP checksums for the packets that it sends to the NFS clients or servers. A value of 0 disables the checksum on UDP packets from the NFS server or client.
nfs_setattr_error	When set to a value of 1, the NFS server ignores invalid setattr requests. This is provided for certain Personal Computer applications. The default value is 0.
nfs_udp_duplicate_cache_size	Specifies the number of entries to store in the NFS server's duplicate cache for the UDP network transport. This option only applies to AIX Version 4.2.1 or later.
nfs_tcp_duplicate_cache_size	Specifies the number of entries to store in the NFS server's duplicate cache for the TCP network transport. This option only applies to AIX Version 4.2.1 or later.
nfs_max_connections	Specifies the maximum number of TCP connections the NFS server allows to be opened at any one time. If new TCP connections are requested from NFS clients and the new connection increases the total beyond this amount, the existing TCP connection will close because of the new connection. This option only applies to AIX Version 4.2.1 or later.
nfs_max_threads	Specifies the maximum number of NFS server threads that are created to service incoming NFS requests. The maximum number may also be specified as a parameter to the nfsd daemon. This option only applies to AIX Version 4.2.1 or later.
nfs_use_reserve_ports	Specifies using non reserved IP port number. The default value 0 will use non reserved IP port number when the NFS client communicates with the NFS server. This option only applies to AIX Version 4.2.1 or later.

Examples

To set the portcheck kernel extension variable to a value of zero, enter:
```
nfso -o portcheck=0
```
To set the udpchecksum variable to its default value of 1, enter:
```
nfso -d udpchecksum
```
To print, in colon-delimited format, a list of all configurable options and their current values, enter:
```
nfso -a -c
```

Related Information

The netstat command, no command.

Network File System (NFS) Overview for System Management in AIX Version 4.3 System Management Guide: Communications and Networks.

TCP/IP Overview for System Management in AIX Version 4.3 System Management Guide: Communications and Networks.

NFS Tuning in AIX Versions 3.2 and 4 Performance Tuning Guide.

List of NFS Commands.