System information

lo o ku p cach e= mode

Specifies how the kernel should manage its cache of directory entries for a given mount

point. Valid arguments for mode are al l , no ne, or po s/po si ti ve.

n f svers= version

Specifies which version of the NFS protocol to use, where version is 2, 3, or 4. This is useful

for hosts that run multiple NFS servers. If no version is specified, NFS uses the highest

version supported by the kernel and mo unt command.

The option vers is identical to nfsvers, and is included in this release for compatibility

reasons.

n o acl

Turns off all ACL processing. This may be needed when interfacing with older versions of

Red Hat Enterprise Linux, Red Hat Linux, or Solaris, since the most recent ACL technology

is not compatible with older systems.

n o lock

Disables file locking. This setting is occasionally required when connecting to older NFS

servers.

n o exec

Prevents execution of binaries on mounted file systems. This is useful if the system is

mounting a non-Linux file system containing incompatible binaries.

n o su id

Disables set-user-i d enti fi er or set-g ro up-i d enti fi er bits. This prevents remote

users from gaining higher privileges by running a setui d program.

p o rt = num

po rt= num — Specifies the numeric value of the NFS server port. If num is 0 (the default),

then mo unt queries the remote host's rpcbi nd service for the port number to use. If the

remote host's NFS daemon is not registered with its rpcbi nd service, the standard NFS

port number of TCP 2049 is used instead.

rsiz e= num an d wsiz e= num

These settings speed up NFS communication for reads (rsi ze) and writes (wsi ze) by

setting a larger data block size (num, in bytes), to be transferred at one time. Be careful

when changing these values; some older Linux kernels and network cards do not work well

with larger block sizes.

Note

If an rsize value is not specified, or if the specified value is larger than the maximum

that either client or server can support, then the client and server negotiate the

largest resize value they can both support.

sec= mode

Specifies the type of security to utilize when authenticating an NFS connection. Its default

setting is sec= sys, which uses local UNIX UID s and GIDs by using AUT H_SY S to

⁠Chapt er 9 . Net work File Syst em (NFS)