NAME
memfs_bufcache_swappct — percentage of buffer cache at which MemFS data buffers start swapping
VALUES
Allowed values
Integral values:
0 - 100
DESCRIPTION
The
memfs_bufcache_swappct
tunable defines the percentage of the maximum memory that can be used by
buffer cache (specified by
dbc_max_pct)
at which
MemFS data buffers begin to get swapped out from the buffer cache.
A lower
percentage allows a lesser portion of the buffer cache to be used by
MemFS data buffers and a higher value allows a higher portion of the buffer
cache to be used by MemFS data buffers.
Restrictions on Changing
The tunable should not be kept at a very high value as the performance
of applications that use the buffer cache might be impacted
when there is high activity on MemFS filesystems.
The tunable is dynamic.
When Should the Value of This Tunable Be Raised?
The value of
memfs_bufcache_swappct
may need to be raised on systems where there are a significant number of
processes that are using MemFS filesystems and for whom performance
is important.
What Are the Side Effects of Raising the Value?
The performance of applications that use the buffer cache might get reduced.
When Should the Value of This Tunable Be Lowered?
The value of
memfs_bufcache_swappct
can be lowered on systems where MemFS activity is less or not needed to be
of high performance.
What Are the Side Effects of Lowering the Value?
This might limit the performance of applications that are using the
MemFS filesystems.
What Other Tunable Values Should Be Changed at the Same Time?
None.
WARNINGS
All HP-UX kernel tunable parameters are release specific.
This parameter may be removed or have its meaning changed in
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.
AUTHOR
memfs_bufcache_swappct
was developed by HP.
