Managing NFS and KRPC Kernel Configurations in HP-UX 11i v2 (November 2013)

Tested values

Default: 32768

Min: 4096

Max: 32768

Note: If the tunable is set to a value less than 4096 or

greater than 32768, an informational warning is issued at

runtime. These values are outside the tested limits.

Restrictions on changing

The nfs3_max_transfer_size_clts tunable is dynamic. System reboot is not required to activate changes

made to this tunable. However, the transfer size for a filesystem is set when the filesystem is mounted.

In order to affect a specific filesystem, you must unmount and re-mount the filesystem after changing

this tunable. Only NFSv3 mount points are affected by changing the value of this tunable.

Modifying the value

For NFS/UDP Filesystems:

To increase the size of NFSv3 UDP requests, set the nfs3_max_transfer_size and

nfs3_max_transfer_size_clts tunables to the same value. Otherwise, the transfer size defaults to the

smaller value of these two tunables.

To decrease the size of NFSv3 UDP requests, decrease the value of the nfs3_max_transfer_size_clts

tunable. For example, to decrease the size of I/O requests on all NFSv3 UDP filesystems to 8 KB, set

the value of nfs3_max_transfer_size_clts to 8192.

Caution: HP strongly discourages increasing

nfs3_max_transfer_size_clts above the default value of

32768, as this can cause NFS/UDP requests to fail. Also, if

the NFS client is experiencing NFS READ failures and the

system is reporting "NFS read failed for server

<servername>: RPC: Can’t decode result" errors, this is an

indication that the nfs3_max_transfer_size,

nfs3_max_transfer_size_clts, or nfs3_max_transfer_size_cots

tunable value was changed while NFS filesystems were

mounted. You must unmount and re-mount the NFS

filesystem to use the new value.