How to set long host names
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How to set long host names

System node and host names on HP-UX have default length limits of 8 and 64 bytes, respectively. The system administrator can configure the system to expand both these limits to 255 bytes.

Some customers who have thousands of systems use a naming convention to clearly identify the physical location and purpose of each machine. For instance, the convention might encode: the geographical location, the computer room name, the purpose (such as application), and an index. Allocating 2 bytes for each field fills the default HP-UX limit of 8 bytes. But two bytes might be too restrictive for some customers (such as when there are more than 100 systems for a particular purpose in one computer room, the index must be 3 bytes).

The expanded_node_host_names 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 names.

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.

On HP-UX 11i v2, the NodeHostNameXpnd product bundle must be installed and the appropriate configuration options enabled to allow up to 255 bytes.

However, on HP-UX 11i v3 this is available by default.

The latest version of this software componente can be obtained at:

Setting up long names

If using HPUX 11i v2, check that the NodeHostXpndEnbl bundle is installed. HP-UX 11i v3 includes de funtionality.

# swlist -l fileset NodeHostXpndEnbl
# Initializing...
# Contacting target "XXXXXXX"...
# Target:  XXXXXXX:/

# NodeHostXpndEnbl                                      B.11.23.01     NodeHostXpndEnbl
  NodeHostXpndEnbl.NODEHOSTXP-KRN                       B.11.23.01     NodeHostXpndEnbl.NODEHOSTXP-KRN
  NodeHostXpndEnbl.NODEHOSTXP-MAN                       B.11.23.01     NodeHostXpndEnbl.NODEHOSTXP-MAN

"Turn on" the setting the tuneable expanded_node_host_names to 1

# kctune -s expanded_node_host_names=1
     ==> Update the automatic 'backup' configuration first? y
       * The automatic 'backup' configuration has been updated.
       * Future operations will update the backup without prompting.
WARNING: Setting the expanded_node_host_names parameter to 1 will allow
         administrators to set node and host names larger than 8 and 64
         characters/bytes, respectively.  It is strongly recommended
         that all related manpages and documentation be understood
         before setting larger names. Larger names can cause some
         applications which use those names to behave incorrectly or
       * The requested changes have been applied to the currently
         running configuration.
Tunable                             Value  Expression  Changes
expanded_node_host_names  (before)      0  Default     Immed
                          (now)         1  1

After this procedure, system commands allows to set long names to the server.

# setuname -t -n XXXXXXX123456
# hostname XXXXXXX123456
# uname -a
HP-UX XXXXXXX123456 B.11.23 U ia64 2027290439 unlimited-user license


  • Node and Host Name Sizes on HP-UX - Using the Expanded Capabilities of HP-UX local

  • 11i v2 long hostname, uname and setuname

  • 11i v3 long hostname, uname and setuname

This page was last modified on 29 April 2008, at 18:55. This page has been accessed 1,756 times.