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

Enable this tunable to ensure the client does not generate a READDIR request for more than 1024
bytes of directory information.
Disable the tunable to allow the client to issue READDIR requests containing up to 8192 bytes of data.
2.1.17 nfs3_async_clusters
Description
The nfs3_async_clusters tunable controls the mix of asynchronous requests that are generated by the
NFSv3 client. There are four types of asynchronous requests:
• read-ahead
• putpage
• pageio
• readdir-ahead.
The client attempts to service these different requests without favoring one type of operation over
another. However some NFSv3 servers can take advantage of clustered requests from NFSv3 clients.
For instance, write gathering is a server function that depends on the NFSv3 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 nfs3_async_clusters
tunable controls the number of outgoing requests for each type before changing types.
The nfs2_async_clusters tunable controls the mix of asynchronous requests generated by NFSv2
clients. The nfs4_async_clusters tunable controls the mix of asynchronous requests generated by
NFSv4 clients. For more information on these tunables, see:
• nfs2_async_clusters
• nfs4_async_clusters
Tested Values
Default: 1
Min: 0
Max: 10