vxfs_bc_bufhwm(5) vxfs_bc_bufhwm(5)
Tunable Kernel Parameters
NAME [Toc] [Back]
vxfs_bc_bufhwm - VxFS buffer cache high water mark(determines the VxFS
buffer cache size)
SYNOPSIS [Toc] [Back]
/usr/bin/kctune -s vxfs_bc_bufhwm={maximum size of buffer cache}
VALUE [Toc] [Back]
Specify an integer value.
Minimum [Toc] [Back]
6144 KB
Maximum [Toc] [Back]
None
Default [Toc] [Back]
0
DESCRIPTION [Toc] [Back]
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 [Toc] [Back]
Use the vxfsstat command to monitor buffer cache statistics and inode
cache usage.
EXAMPLES [Toc] [Back]
Set the maximum of size of buffer cache at 300000:
# kctune -s vxfs_bc_bufhwm=300000
WARNINGS [Toc] [Back]
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,
Hewlett-Packard Company - 1 - HP-UX 11i Version 2: Sep 2004
vxfs_bc_bufhwm(5) vxfs_bc_bufhwm(5)
Tunable Kernel Parameters
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.
SEE ALSO [Toc] [Back]
kctune(1M), vxfsstat(1M), vx_maxlink(5), vx_ninode(5),
vxfs_ifree_timelag(5).
Hewlett-Packard Company - 2 - HP-UX 11i Version 2: Sep 2004 [ Back ] |
