NAME
vxfs_bc_bufhwm — VxFS buffer cache high water mark(determines the VxFS buffer cache size)
SYNOPSIS
/usr/bin/kctune -s vxfs_bc_bufhwm={maximum size of buffer cache}
VALUE
Specify an integer value.
DESCRIPTION
VxFS maintains a buffer cache in the kernel for frequently accessed file system metadata in addition to the HP-UX kernel buffer cache that caches the file data.
vxfs_bc_bufhwm
tunable parameter determines the size of the VxFS buffer cache (the maximum amount of memory that can be used to cache VxFS metadata).
The default value computed based on the amount of system memory
ensures good system performance across a wide range of applications.
The value of
vxfs_bc_bufhwm
is specified in
kilobytes. To improve performance during application
loads that cause frequent file system metadata changes on the system
(for example, a high rate of file creation or deletion, or accessing
large directories), change the value of
vxfs_bc_bufhwm.
Notes
Use the
vxfsstat
command to monitor buffer cache statistics and inode
cache usage.
EXAMPLES
Set the maximum of size of buffer cache at 300000:
# kctune -s vxfs_bc_bufhwm=300000
WARNINGS
All HP-UX kernel tunable parameters are release specific.
This parameter may be removed or its meaning may change in the
future releases of HP-UX.
Installation of optional kernel software, from HP or other vendors,
may cause changes to tunable parameter values. After installation,
some tunable parameters may no longer be at the default or
recommended values. For information about the effects of
installation on tunable values, consult the documentation
for the kernel software being installed.
For information about optional kernel software that was
factory installed on your system, see
HP-UX Release Notes
at
http://docs.hp.com.
