NAME
memfs_bufcache_metapct — maximum percentage of buffer cache which can accommodate MemFS metadata
VALUES
Allowed values
Integral values:
10 - 50
DESCRIPTION
The metadata of all the MemFS filesystems configured in the system
is stored in the buffer cache.
The
memfs_bufcache_metapct
tunable defines the maximum percentage of buffer cache which
can accommodate MemFS metadata.
Metadata buffers of a MemFS filesystem are never swapped out of the buffer
cache or reused, unless the MemFS filesystem is unmounted.
Restrictions on Changing
The tunable should not be kept at a very high value as it may
impact the performance of applications that use the buffer cache.
The tunable is dynamic.
When Should the Value of This Tunable Be Raised?
The value of
memfs_bufcache_metapct
may need to be raised on systems where there are a large number of files
and directories in MemFS filesystems.
What Are the Side Effects of Raising the Value?
The performance of applications that perform I/O on filesystems that use the
buffer cache, other than MemFS, might get reduced.
When Should the Value of This Tunable Be Lowered?
The value of
memfs_bufcache_metapct
can be lowered on systems with small or no mounted MemFS filesystems.
What Are the Side Effects of Lowering the Value?
This limits the number of files and directories that can be created
in 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_metapct
was developed by HP.
