nfs4cl Command

Purpose

Displays or modifies current NFSv4 statistics and properties.

Syntax

/usr/sbin/nfs4cl [subcommand] [path] [argument]

Description

Use the nfs4cl command to display all the fsid information on the client or modify filesystem options of an fsid.

Note: The nfs4cl updates affect newly accessed files in the filesystem. An unmount and remount are required to affect all previously accessed files.

Subcommands

resetfsoptions Subcommand

This subcommand resets all the options for the fsid back to the default options.

Note: The cio and dio options can be reset with the resetfsoptions subcommand, but the cio and dio behavior is not actually turned off until the NFS filesystem is unmounted and then remounted.

setfsoptions Subcommand

This subcommand will take a path and an argument. The path specifies the target fsid structure and the argument is the file system options. It will set the internal fsid to use the options specified by the argument. Here is the list of possible arguments:

Item	Description
rw	Specifies that the files or directories that bind to this path (fsid) are readable and writable.
ro	Specifies that the files or directories that bind to this path (fsid) are read only.
acdirmax	Specifies the upper limit for the directory attribute cache time out value.
acdirmin	Specifies the lower limit for the directory attribute cache time out value.
acregmax	Specifies the upper limit for the file attribute cache time out value.
acregmin	Specifies the lower limit for the file attribute cache time out value.
cio	Specifies the filesystem to be mounted for concurrent readers and writers. I/O on files in this filesystem behave as if the file was opened with O_CIO specified in the open() system call.
cior	Specifies to allow read-only files to open in the file system. I/O on files in this filesystem will behave as if they had been opened with O_CIO \| O_CIOR specified in the open() system call.
dio	Specifies that I/O on the filesystem behaves as if all of the files were opened with O_DIRECT specified in the open() system call.
hard	Specifies that this fsid will use hard mount semantics.
intr	Specifies that the fsid operations are interruptible.
maxpout=value	Specifies the pageout level for files on this filesystem at which threads should be slept. If maxpout is specified, minpout must also be specified. This value must be non-negative and greater than minpout. The default is the kernel maxpout level.
minpout=value	Specifies the pageout level for files on this filesystem at which threads should be readied. If minpout is specified, maxpout must also be specified. This value must be non-negative. The default is the kernel minpout level.
noac	Does not use attribute cache.
nocto	Specifies no close-to-open consistency.
nointr	Specifies that the fsid is non-interruptible.
prefer=servername	Administratively sets the preferred server to use when data exists at multiple server locations. The server name can be in short name, long name, IPv4, or IPv6 format, but the client must be able to resolve the server name when the nfs4cl command is run.
rbr	Utilizes the release-behind-when-reading capability. When sequential reading of a file in this filesystem is detected, the real memory pages used by the file will be released once the pages are copied to internal buffers.
rsize	Specifies the read size for the RPC calls to the server.
retrans	Specifies the number of RPC retransmits to attempt with soft semantics.
soft	Specifies the fsid operation that will use soft mount semantics.
timeo	Specifies the time out value for the RPC calls to the server.
wsize	Specifies the write size for the RPC calls to the server.
nodircache	Does not use directory cache.

showfs Subcommand

This subcommand displays filesystem specific information on the server that is currently accessed by the client. The information includes server address, remote path, fsid, and local path. If path is provided, additional information, such as fs_locations and fsid options, are displayed.

showstat Subcommand

This subcommand shows information similar to what the df command prints out for each fsid that exists on the client. The information includes fields such as, Filesystem, 512-blocks, Free, %Used, Iused, %Iused, and Mounted on.

delegreturn Subcommand

This subcommand accepts file path as its input argument. This subcommand will allow a system administrator to instruct NFS v4 client to return delegations on the file specified by the input path name.

help Subcommand

This subcommand prints the usage statement.

Exit Status

Item	Description
0	The command completed successfully.
>0	An error occurred.

Examples

To display all the fsid structure on the client, type:
```
nfs4cl showfs
```
To set the file system options of /mnt/usr/sbin to include only retrans=3, type:
```
nfs4cl setfsoptions /mnt/usr/sbin retrns=3
```
To reset the filesystem options for /mnt/use/sbin, type:
```
nfs4cl resetfsoptions /mnt/user/sbin
```
To show df command output for /mnt/usr/sbin, type:
```
nfs4cl showstat /mnt/usr/sbin
```
To make the client failover to server boo when replication occurs in /mnt/usr/sbin, type:
```
nfs4cl setfsoptions /mnt/usr/sbin prefer=boo
```

Location

/usr/sbin/nfs4cl