ncdnode.5 (2010 09)

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ncdnode(5) ncdnode(5)
(Tunable Kernel Parameters)
NAME
ncdnode - maximum number of open CDFS files (system-wide)
VALUES
Failsafe
150
Default
150
Allowed values
The minimum value allowed is 25. The maximum value allowed is memory limited.
Specify a positive integer value.
DESCRIPTION
ncdnode defines the number of slots in the inode table for in the CD-ROM file systems (CDFS). This
number limits the number of open nodes that can be in memory for CDFS file systems at any given time.
It is functionally similar to ninode but applies only to CD-ROM file systems.
Who Is Expected to Change This Tunable?
This tunable may need to be modified on systems that run applications requiring access to CD-ROM file
systems.
Restrictions on Changing
The
cdfs kernel module, which provides the file system type specific support for CD-ROM file systems, is
now a dynamically loadable kernel module (DLKM). Any changes to the value of the tunable ncdnode
will take effect after the cdfs kernel module is unloaded and re-loaded (see kcmodule (1M)), or after sys-
tem reboot.
When Should the Value of This Tunable Be Raised?
The value may need to be raised when running applications which require large numbers of simultane-
ously open CDFS files.
What are the Side Effects of Raising the Value?
More system memory will be consumed for the CDFS nodes. A larger static inode table for CDFS will be
created based on the value of
ncdnode upon cdfs kernel module load or system reboot
When Should the Value of This Tunable Be Lowered?
The value can be lowered to limit the number of CDFS open files on the system and reduce memory con-
sumption.
What are the Side Effects of Lowering the Value?
Less system memory will be consumed for the CDFS inodes upon
cdfs kernel module load or system
reboot.
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 parame-
ter 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://www.hp.com/go/hpux-core-docs.
AUTHOR
ncdnode was developed by HP.
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1