fs-nfs3

NFS 3 client filesystem (QNX Neutrino)

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You must be root to start this manager.

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Syntax:

fs-nfs3 [-b num] [-B size] [-D] [-e] [-h] 
        [-i nodes] [-r] [-s] [-S] [-t] 
        [-u] [-v[v]...] [-w delay=sec] 
        [-w number=num] [-w size=num] [-T threads] [-Z n]
        [-w sync=hard] [-Z n] [server:export] [mountpoint]
        [[-erStu] [-Z n] server:export mountpoint ...]

Runs on:

Neutrino

Options:

server

The name of the NFS server.

export

The directory to be exported from the server.

mountpoint

The name under which the exported directory is to be mounted.

The following options apply to all mountpoints:

-b num

Use num buffers (default: 200).

-B size

Set the buffer size to size bytes. The default is set by the first server, and is usually 8K.

-D

Run in the foreground.

-h

Display usage information.

-i nodes

Set the number of inodes to nodes.

-v[v]...

Verbose output; add more v characters for more verbosity. In order to capture the log messages, you need to have syslogd running.

The following options apply only to the next mountpoint specified on the command line:

-e

Set the NO EXEC flag for the mounted filesystem.

-r

Set the READ ONLY flag for the mounted filesystem.

-S

Don't cache symlinks.

-s

Use a soft mount.

-t

Use TCP instead of UDP. If this fails, fs-nfs3 uses UDP.

-T num

Set the number of threads. The default is 5.

-u

Use UDP (which is the default). If this fails, fs-nfs3 fails.

-w delay=sec

Indicate the time, in seconds, after which the data will be flushed to the server. The default is 2 seconds.

-w number=num

Number of buffers (default is 10.) Each buffer manages content for one file. The default value indicates 10 files can be buffered simultaneously.

-w size=num

Size of the buffer, in units of 1K (default is 8.)

-w sync=hard

Turn off write caching.

-Z n

The value of n indicates how to attach to the path:

• B or b — attach before other managers.
• A or a — attach after other managers.
• O or o — make the attachment opaque; don't resolve to mountpoints with shorter pathname matches. The pathname resolver tries to find the longest match against all pathnames attached.

The default is none of these. For more information, see “Ordering mountpoints” in the Process Manager chapter of the System Architecture guide.

Description:

The fs-nfs3 filesystem manager is an NFS 3 client operating over TCP/IP. To use it, you must have an NFS server.

When you use fs-nfs3 with write caching (the default), you benefit from enhanced filesystem performance. However, there can be interoperability issues if more than one NFS client accesses the same file on the NFS server. If fs-nfs3's cached data hasn't been written to the NFS server, another NFS client attempting to read the same file won't see the changes to the file until they're written to the server at a later point. If you want fs-nfs3 to write file modifications immediately to the NFS server, use the -w sync=hard option to turn off write caching.

This filesystem manager requires a TCP/IP transport layer, such as the one provided by io-pkt*. It also needs socket.so and libc.so.

By default, this utility does not set any upper limit for number of inodes.

You can also create mountpoints with the mount command by specifying nfs for the type and -o ver3 as an option. You must start fs-nfs3 before creating mountpoints in this manner. If you start fs-nfs3 without any arguments, it runs in the background so you can use mount. The options that you can use with mount include the following:

tcp

Use TCP instead of UDP. If this fails, mount uses UDP.

udp

Use UDP (which is the default). If this fails, mount fails.

nocachesymlink

Don't cache symlinks.

ver3

Use fs-nfs3 instead of fs-nfs2.

soft

Use a soft mount (i.e. break the connection if unable to reach the server).

Examples:

Mount the qnx_bin export as /bin from an NFS server named server_node:

fs-nfs3 server_node:/qnx_bin /bin &

Mount /nfs1 using TCP, and /nfs3 using UDP:

fs-nfs3 -t host1:/ /nfs1 host2:/ /nfs3

Mount both using TCP:

fs-nfs3 -t host1:/ /nfs1 -t host2:/ /nfs3

Mount an NFS filesystem (fs-nfs3 must be running first):

mount -t nfs -o ver3 server_node:/qnx_bin /bin

Mount an NFS filesystem, using TCP (fs-nfs3 must be running first):

mount -t nfs -o tcp,ver3 server:/tmp /mnt

Caveats:

If possible, you should use fs-nfs3 instead of fs-nfs2.

See also:

fs-cifs, fs-nfs2, io-pkt*, mount, syslogd, umount

Filesystems chapter of System Architecture

QNX Neutrino User's Guide:

• “NFS filesystem” in the Working With Filesystems chapter
• “Filesystem limits” in the Understanding System Limits chapter