nstrpty(5) nstrpty(5)
Tunable Kernel Parameters
NAME [Toc] [Back]
nstrpty - maximum number of STREAMS-based pseudo terminals (pts)
VALUES [Toc] [Back]
Default
nstrpty = 60
Allowed Values [Toc] [Back]
Minimum : 1
Maximum : System memory size
DESCRIPTION [Toc] [Back]
nstrpty is the number of STREAMS-based pseudo terminal (pts) drivers
that a system can support. The pty driver provides support for a
device-pair called a pseudo terminal. A pseudo terminal is a pair of
character devices, a master device, and a slave device. These allow
communication between an application process and a server process.
When sending data to pty devices (such as windows), a pty device must
exist for every window that is open at any given time.
nstrpty should be set to a value that is equal to, or greater than,
the number of pty devices on the system that will be using STREAMSbased
I/O pipes. Using a parameter value significantly larger than
the number of ptys is not recommended. nstrpty is used when creating
data structures in the kernel to support STREAMS-based ptys, and an
excessively large value wastes kernel memory space.
Who Is Expected to Change This Tunable?
Super users. Changes to this tunable take effect at the next reboot.
When Should the Value of This Tunable Be Raised?
This tunable value needs to be raised when the system runs out of
ptys.
What Are the Side Effects of Raising the Value?
More system memory is used.
When Should the Value of This Tunable Be Lowered?
This value should be lowered when a minimal system is being created.
What Are the Side Effects of Lowering the Value?
The system may run out of ptys.
WARNINGS [Toc] [Back]
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,
Hewlett-Packard Company - 1 - HP-UX 11i Version 2: Sep 2004
nstrpty(5) nstrpty(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.
AUTHOR [Toc] [Back]
nstrpty was developed by HP.
SEE ALSO [Toc] [Back]
kctune(1M), pts(7).
Hewlett-Packard Company - 2 - HP-UX 11i Version 2: Sep 2004 [ Back ] |