npty(5)npty(5)NAMEnpty - maximum number of BSD pseudo terminals (ptys)
VALUES
Default
Allowed Values
DESCRIPTION
is the number of pseudo terminal (pty) drivers that a system can sup‐
port. 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.
Using a parameter value significantly larger than the number of ptys is
not recommended. An excessively large value wastes kernel memory
space.
Who Is Expected to Change This Tunable?
Users with the privilege. See privileges(5) for more information about
privileged access on systems that support fine-grained privileges.
Restrictions on Changing
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
All HP-UX kernel tunable parameters are release specific. This parame‐
ter 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 val‐
ues. For information about the effects of installation on tunable val‐
ues, consult the documentation for the kernel software being installed.
For information about optional kernel software that was factory
installed on your system, see at
AUTHOR
was developed by HP.
SEE ALSOkctune(1M), privileges(5), pty(7).
Tunable Kernel Parameters npty(5)