NAME
vx_ncsize — the number of bytes to be reserved for the directory path-name cache used by the VxFS file system
VALUES
Specify an integer value.
DESCRIPTION
The VxFS file system uses a name cache to store directory path name
information related to recently accessed directories in the file system.
Retrieving this information from a name cache allows the system to
access directories and their contents without having to use direct disk
accesses to find its way down a directory tree every time it needs to
find a directory that is used frequently.
Using a name cache in this way can save considerable overhead,
especially in large applications such as databases
where the system is repetitively accessing
a particular directory or directory path.
vx_ncsize
specifies how much space, in bytes, is set aside
for the VxFS file system manager to use for this purpose.
The default value is sufficient for most typical HP-UX systems,
but for larger systems
or systems with applications that use VxFS disk I/O intensively,
some performance enhancement may result from expanding the cache size.
The efficiency gained, however,
depends greatly on the variety of directory paths
used by the application or applications,
and what percentage of total process time is expended
while interacting with the VxFS file system.
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.
AUTHOR
vx_ncsize
was developed by HP.
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