Managing NFS and KRPC Kernel Configurations in HP-UX 11i v2 (Oct 2008)

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. You 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
results in increased throughput. However, if the server response is delayed or the network is
overloaded, the number of timeouts can increase.
HP recommends leaving this tunable enabled because it helps the system minimize NFS packet loss
on congested networks.
2.1.17 nfs3_hacc_size
Description
There are two algorithms to search for entries in the access cache: linear and hashed. The default
search algorithm is linear. To use a hashed search, enable the nfs3_new_acache tunable. The speed
of the hashed search is controlled by the number of hash buckets. The nfs3_hacc_size tunable enables
you to specify the number of hash buckets to be used by the NFSv3 access cache.
Tested Values
Default: 32
Min: 2
Max: 4000
Restrictions on Changing
The nfs3_hacc_size tunable is dynamic. System reboot is not required to activate a change made to
this tunable. Only NFSv3 mount points are affected when you change the value of this tunable.
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