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

Note: Before you enable this tunable, you should install the
Virtual Memory fix (SR: 8606472738) included in patch
PHKL_36457.
Restrictions on Changing
The nfs2_srv_read_copyavoid tunable is dynamic. System reboot is not required to activate changes
made to this tunable. Only NFSv2 mount points are affected by changing the value of this tunable.
Modifying the Value
Enable this tunable to potentially improve the performance of applications that issue read requests in
NFSv2 filesystems.
Warning: Under certain circumstances, enabling the
nfs2_srv_read_copyavoid/nfs3_srv_read_copyavoid tunable
may cause the following problems:
– Memory corruption with the message block getting
corrupted (QXCR1000879579)
– Data corruption during READ, when the nfs2_bsize/
nfs3_bsize tunable value is greater than 64 KB
(QXCR1000855994)
HP recommends disabling the
nfs2_srv_read_copyavoid/nfs3_srv_read_copyavoid
tunables until these problems have been fixed. Fixes for
these problems are planned for a future ONCplus release.
2.2.4 nfs3_do_readdirplus
Description
The nfs3_do_readdirplus tunable controls the NFSv3 READDIRPLUS functionality on the NFS server. In
NFS-mounted filesystems, performance of some applications that read huge directories suffers if they
use READDIRPLUS instead of READDIR. These applications do not require the extended attribute
information returned by READDIRPLUS. Usage of READDIR by these applications can result in a
performance improvement.
Tested Values
Default: 1 (READDIRPLUS functionality is enabled)
Min: 0 (READDIRPLUS functionality is disabled)
Max: 1
Restrictions on Changing
The nfs3_do_readdirplus tunable is dynamic. System reboot is not required to activate changes made
to this tunable. Only NFSv3 mount points are affected by changing the value of this tunable.