VERITAS Storage Foundation 4.1 Oracle Administrator's Guide

Tuning HP-UX Prerelease 8 September 2005, 8:55am
416 VERITAS Storage Foundation for Oracle Administrator’s Guide
Tuning HP-UX
To achieve optimal performance using Quick I/O, certain HP-UX parameters need to be tuned.
Changing these parameters requires modifying the HP-UX kernel settings, rebuilding the kernel,
and rebooting the system. See the HP-UX System Administration Tasks manual for the detailed
procedure on how to reconfigure the HP-UX kernel. If you use SAM, the HP-UX system
administration utility, to rebuild your kernel, make sure the Overwrite /stand/system button on the
Reboot the System dialog menu is selected. The rest of this section describes the important tuning
parameters.
Note The settings for all tunable parameters depend on such factors as the size of your system and
database, the database load, and the number of users. In some cases we make suggestions for
setting the parameters; however, you should always consult the Oracle Installation Guide for
your system and version, and use the settings recommended by Oracle when provided.
max_thread_proc
This parameter sets the maximum number of threads that a process can create. The high
performance of VxFS and the Quick I/O driver depend on the value of this tunable. Set the
max_thread_proc parameter to 1200.
asyncdsk, asyncdsk_included, and max_async_ports
These parameters are used for including and configuring the asynchronous I/O driver in the HP-UX
kernel, resulting in less I/O overhead and higher throughput. The parameter max_async_ports
sets the maximum number of connections between user processes and the asyncdsk driver. See
your Oracle documentation for the recommended value, or set max_async_ports to 1024 if a
value is not recommended.
eqmemsize
The I/O subsystem uses a pool of memory allocated by the eqmemsize parameter for I/O system
memory. The eqmemsize parameter specifies the minimum amount of this equivalently mapped
memory. The exhaustion of this memory pool degrades I/O performance, thus impacting
application performance. See your Oracle documentation for the recommended value, or set
eqmemsize to 512 if a value is not recommended.