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

Max: 36000 seconds (10 hours)
Note: If the tunable is set to a value greater than 36000
seconds, an informational warning is issued at runtime. Any
value greater than 36000 is outside the tested limits.
Restrictions on Changing
The nfs_exi_cache_time tunable is dynamic. System reboot is not required to activate changes made
to this tunable.
Modifying the Value
The size of the NFS authentication cache can be modified by changing the duration of time a cache
entry is held before purging. To decrease the load on the rpc.mountd daemon, increase the value of
this tunable. Be aware that increasing the value also increases the amount of system resources used to
maintain the cache. Conversely, a small cache increases the load on rpc.mountd and could
potentially result in reduced NFS performance.
2.2.2 nfs_portmon
Description
The nfs_portmon tunable checks whether the source port from which a client request was sent is a
reserved port.
The NFS server performs a number of integrity checks against client requests prior to servicing them.
In BSD-based systems, ports in the range of 1-1024 are reserved for processes that are run by root.
When enabled, the NFS server prevents users from writing their own RPC-based applications to
defeat the access-checking that the NFS client performs.
Tested Values
Default: 0 (Server does not check if source port is in reserved port range)
Min: 0
Max: 1 (Server checks if the source port is in reserved port range)
Restrictions on Changing
The nfs_portmon tunable is dynamic. System reboot is not required to activate changes made to this
tunable.
Modifying the Value
Enable this tunable to force the server to verify that each client request originated from a reserved
port.
2.2.3 nfs2_srv_read_copyavoid
Description
When servicing read requests from NFS clients, the server will make separate copies of the read data
in kernel memory multiple times as part of processing each request. HP recently identified one of these
in-memory copies as being unnecessary, and by eliminating this additional copy the performance of
servicing read requests increases. The nfs2_srv_read_copyavoid tunable controls whether the NFSv2
server will avoid this unnecessary in-memory copy or continue using the standard read logic.