Managing NFS and KRPC Kernel Configurations in HP-UX 11i v3 (762807-001, March 2014)

The nfs2_do_symlink_cache tunable caches the contents of symbolic links in NFSv2 mounted
filesystems. The nfs4_do_symlink_cache tunable caches the contents of symbolic links in NFSv4
mounted filesystems. For more information on these tunables, see:
• nfs2_do_symlink_cache
• nfs4_do_symlink_cache
Tested Values
Default: 1 (Symbolic link cache is enabled)
Min: 0 (Symbolic link cache is disabled)
Max: 1
Restrictions on Changing
The nfs3_do_symlink_cache tunable is dynamic. System reboot is not required to activate changes
made to this tunable. Only NFSv3 mount points are affected by changing the value of the
nfs3_do_symlink_cache tunable.
Modifying the Value
Enable this tunable to cache the contents of symbolic links. Because the client uses the cached version,
changes made to the contents of the symbolic link file are not immediately visible to applications
running on the client.
To make the changes made to the symbolic link file immediately visible to applications on the client,
disable this tunable. Disabling the tunable can result in more over-the-wire requests from the client if
filesystems are mounted with NFSv3 and contain symbolic links.
2.1.21 nfs3_dynamic
Description
The nfs3_dynamic tunable controls the dynamic retransmission feature for NFSv3 mounted filesystems.
The dynamic retransmission feature is designed to reduce NFS retransmissions by monitoring server
response time and adjusting read and write transfer sizes on NFSv3 mounted filesystems using
connectionless transports such as UDP.
The nfs2_dynamic tunable controls the dynamic retransmission feature for NFSv2 mounted filesystems.
For more information on the tunable, see nfs2_dynamic.
Tested Values
Default: 0 (Dynamic retransmission is disabled)
Min: 0
Max: 1 (Dynamic retransmission is enabled)
Restrictions on Changing
The nfs3_dynamic tunable is dynamic. System reboot is not required to activate changes made to this
tunable. However, the dynamic retransmission feature is set per filesystem at mount time. The system
administrator must unmount and re-mount each filesystem after changing this tunable. Only NFSv3
mount points are affected when you change the value of this tunable.
Modifying the Value
In congested networks, sending smaller sized NFS data packets can help if the network is dropping
larger data packets. Enabling this tunable enables you to adjust the read and write transfer sizes for
successful NFS I/O. If packets are not being dropped in the network, disabling this functionality