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

Expanding the window size in some applications (such as, dtfile – CDE file manager)

shows the first component of the host name. The CDE login window cannot be resized.

Core Files

The application core file format on HP-UX 11i v3 has been updated so that it can

accommodate the maximum node-name length.

This updated format was introduced as an option with HP-UX 11i v2 (and likely used only on

systems with the optional NodeHostNameXpnd product bundle installed). Core files

generated with the prior format contain only up to the first 8 bytes of the node name.

Debuggers do not have the whole node name when accessing such core files.

File Names

File names in the default HP-UX file system configurations have a maximum length of 255

bytes. This maximum cannot accommodate names created by applications that include the

host name with a short prefix or suffix, when the total length of the host name, prefix, and

suffix exceeds 255. Host names generally do not get sufficiently long to make this a

problem.

Note also that the maximum length of a full path name equals the value of the PATH_MAX

parameter (usually 1024 bytes). In a small number of cases (CDE is one example), the host

name is used in a directory name superior to a file name that also contains the host name.

While this path does not exceed the PATH_MAX value, the value can be exceeded if the host

name appears multiple times in the path of some application file.

Some file system configurations support file names only up to 14 bytes. These systems

should not be assigned host or node names longer than 8 bytes so that the node or host

name can be used in the formation of file names within some applications.

Ignite-UX

Ignite-UX supports node and host names up to 63 bytes (plus null terminator).

Internet Services

The /etc/gated.conf(4) and /etc/dhcpv6tab(4) configuration files (used by

gated(1m) and dhcpv6d, respectively) support tokens up to 200 bytes (including null

terminator). Setting a fully qualified host name for the system could run into this limitation.

However, this is unlikely because fully qualified host names generally do not get that long. A

future version of HP-UX might remove this limitation.

The mail ID size supported by sendmail(1m) has been increased from 255 to 511 bytes to

accommodate maximum-size host names. However, mail being routed through systems not

capable of handling these sizes (such as systems prior to HP-UX 11i v2 September 2004

Update) might result in delivery failures. This is very unlikely, because fully qualified host