expanded_node_host_names(5)expanded_node_host_names(5)NAMEexpanded_node_host_names - enable maximum length expansion of the sys‐
tem node and host names
The tunable controls the length of the system node and host names.
When this tunable value is 0, the system utilities used to set node and
host names allow compatible name lengths. That is, 8 and 64 bytes for
node and host name, respectively. When this tunable value is 1, the
utilities allow expanded lengths up to 255 bytes.
Changing this tunable does not affect the current system node and host
Node and host names larger than 8 and 64 bytes, respectively, can cause
anomalous or incorrect behavior in applications using these names. See
the WARNINGS section for more information.
Who Is Expected to Change This Tunable?
The system administrator may change this tunable when it is necessary
to change the maximum allowed length of the system node and/or host
Restrictions on Changing
This tunable is dynamic. Changing its value to 1 immediately allows
the administrator to assign expanded (up to 255 bytes) node or host
names. Changing its value to 0 enforces the compatible maximum of 8
and 64 byte node and host names on any subsequent name setting but does
not affect the current name settings.
When Should the Value of This Tunable Be Raised?
This tunable may be raised to 1 when it is necessary to assign an
expanded node and/or host name.
What are the Side Effects of Raising the Value?
Raising the tunable value to 1 causes the system utilities used to set
node and host names to allow names up to 255 bytes.
When Should the Value of This Tunable Be Lowered?
This tunable should be lowered to 0 when it is determined that expanded
node and host names are not necessary.
What are the Side Effects of Lowering the Value?
Lowering the tunable value to 0 causes the system utilities used to set
node and host names to allow names up to 8 and 64 bytes, respectively.
What Other Tunable Values Should Be Changed at the Same Time?
For more information on usage see the whitepaper
Node and host names in excess of 8 and 64 bytes, respectively, can
cause anomalous behavior or failure in applications using these names.
The administrator should read and understand the issues as described in
the related documentation (see the whitepaper and nodehostnamesize(5)).
Warnings are always issued from the tunable handler when this tunable
When this tunable value is 0 (off), the system interfaces and commands
which set node and host names quietly truncate inputs to 8 or 64 bytes,
respectively. This behavior is consistent with previous versions.
There is no error nor warning provided.
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
All HP-UX kernel tunable parameters are release specific. This parame‐
ter may be removed or have its meaning changed in future releases of
was developed by HP.
SEE ALSOhostname(1), uname(1), setuname(1M), gethostname(2), sethostname(2),
uname(2), hostname(5), nodehostnamesize(5).
whitepaper, available on
Tunable Kernel Parameterexpanded_node_host_names(5)