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

The client attempts to service these different requests without favoring one type of operation over
another. However some NFSv2 servers can take advantage of clustered requests from NFSv2 clients.
For instance, write gathering is a server function that depends on the NFSv2 client sending out
multiple WRITE requests in a short time span. If requests are taken out of the queue individually, the
client defeats this server functionality designed to enhance performance. The nfs2_async_clusters
tunable controls the number of outgoing requests for each type before changing types.
The nfs3_async_clusters tunable controls the mix of asynchronous requests generated by NFSv3
clients. The nfs4_async_clusters tunable controls the mix of asynchronous requests generated by
NFSv4 clients. For more information on these tunables, see:
• nfs3_async_clusters
• nfs4_async_clusters
Tested Values
Default: 1
Min: 1
Max: 10
Note: If the tunable is set to a value greater than 10
asynchronous requests, an informational warning is issued
at runtime. Any value greater than 10 is outside the tested
limits.
Restrictions on Changing
The nfs2_async_clusters tunable is dynamic. System reboot is not required to activate changes made
to this tunable. Any change made to the value of the tunable is effective immediately. However, the
cluster setting is set per filesystem at mount time. The system administrator must unmount and re-mount
each filesystem after changing this tunable. Only NFSv2 mount points are affected by changing the
value of the nfs2_async_clusters tunable.
Modifying the Value
If server functionality depends upon clusters of operations coming from the client, increase the value of
this tunable. However, this can impact the operations in other queues because they have to wait until
the current queue is empty or the cluster limit is reached.
Note: Setting the value of nfs2_async_clusters to 0 causes all
queued requests of a particular type to be processed before
moving to the next type.
2.1.9 nfs2_bsize
Description
The nfs2_bsize tunable controls the logical block size used by NFSv2 clients. Block size represents the
amount of data the client reads from or writes to the server.