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

2.2 NFS Server Tunables
Table 2.2-1 lists the NFS server tunables. The last column specifies which NFS patch first introduced
the tunable.
Table 2.2-1 NFS Server Tunables
Kctune Tunable Name Range Default Value Units Patch ID
nfs_portmon 0 or 1 0 Boolean PHNE_33982
nfs_exportfs_rwlock* 0 or 1 0 Boolean PHNE_34550
nfs_srv_read_copy_avoid 0 or 1 0 Boolean PHNE_35118
nfs3_do_readdirplus 0 or 1 1 Boolean PHNE_33982
* This tunable is obsolete after the HP-UX 11i v2 release.
2.2.1 nfs_portmon
Description
The nfs_portmon tunable verifies whether the source port from which a client request originates 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 a change 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.
2.2.2 nfs_exports_rwlock
Description
In an NFS multi-processor server, if the number of NFS client requests handled is high NFS
performance may degrade due to excessive contention for the lock protecting the list of exported
filesystems. Enable the nfs_exportfs_rwlock tunable to replace the exportfs (hashed exclusive) locks
with the hashed reader/writer spinlocks and potentially improve NFS throughput.
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