topic Re: Length of hostname in Operating System - HP-UX

Length of hostname

Juan Gonzalez_2 — Tue, 10 Dec 2002 00:08:52 GMT

How many characters long can the name of a unix server be? I have read 16 characters long. I have found different answers.

Re: Length of hostname

Christopher Caldwell — Tue, 10 Dec 2002 00:11:48 GMT

64:

The sethostname() system call sets the name of the host processor to
name, which has a length of namelen characters. At system boot time
sethostname() is normally executed by the hostname command (see
hostname(1)) in the /sbin/init.d/hostname script. Host names are
limited to MAXHOSTNAMELEN characters, as defined in .

$ grep MAXHOSTNAMELEN /usr/include/sys/param.h
#define MAXHOSTNAMELEN 64 /* max length of hostname */

Re: Length of hostname

Ian Kidd_1 — Tue, 10 Dec 2002 01:34:12 GMT

While the maximum allowable length of the hostname is 64 characters long, it is recommended that you shouldn't exceed 8.

For example, you want the `uname` command to be able to display the entire hostname. uname uses utsname which is defined in usr/include/sys/utsname.h as: #define UTSLEN 9
this is a 9 character null-terminated string (per the man pages). I've read (but am not positive) that the maximum is 8 because of 8 characters + null.

There's other issues I've read about (UUCP, etc.) for having a hostname longer than 8 characters, so it might be best sticking with the recommended length if you can.

Re: Length of hostname

harry d brown jr — Tue, 10 Dec 2002 01:38:31 GMT

I would never bless any system name over 8 characters, as a matter of just being stubborn.

You actually COULD have code that might fail if you exceed 8 characters, but like the limit says (64), if you wish to go beyond 8 characters, that's your choice :-)

live free or die
harry

Re: Length of hostname

Scott Van Kalken — Tue, 10 Dec 2002 02:26:43 GMT

I tried this for fun once on a 10.20 box a while ago. Gave it a 30 character hostname.

GSP was only half working.

SDUX nearly had a heart attack, and some other things didn't work (like uname).

The biggest show stopper I found was SDUX though.

Re: Length of hostname

Ravi_8 — Tue, 10 Dec 2002 05:21:14 GMT

Hi,

you can have any length for hostname, but while displaying it shows only first 8 characters,

Re: Length of hostname

Jean-Louis Phelix — Tue, 10 Dec 2002 07:14:41 GMT

hi,

It's definitly 8 if you don't want to go in big troubles ... Consider MAXHOSTNAMELEN (64)as the maximum length for fully qualified hostnames (host.domain.com) and UTSLEN (8+1) for real hostnames displayed by uname -n command.

Regards.

Re: Length of hostname

donne007 — Tue, 10 Dec 2002 10:00:07 GMT

HI
The system Takes character's up to infinity but while displaying it shows only 8 characters. since Unmae displays only 8 chars ..
Cheers
Asif

Re: Length of hostname

Ravi_8 — Tue, 10 Dec 2002 10:57:11 GMT

Hi, again

The Software Distributor tools (swinstall, etc.) use the system's hostname, and uname value interchangeably, and since the uname value is restricted to 8 characters, the SD tools would fail if the hostname is longer than 8.

Re: Length of hostname

Steven E. Protter — Tue, 10 Dec 2002 13:59:13 GMT

Re: Length of hostname

Steven E. Protter — Tue, 10 Dec 2002 14:00:13 GMT

This is one area where Linux is ahead of HP-UX.

My web server for my web hosting biz at home runs Linux. The main server host name is jerusalem, my favorite city. That's nine characters btw

I tried that with an HP-UX box and had issues with swinstall and Ignite. That server is now called Moriah (the Temple Mount).

8 character limit is the way to go with HP-UX and thats 11.11 btw.

Yes, it was stupid to try and name two servers I work with the same thing, but that's not how it happened. The jerusalem box at home went in after I figured out I couldn't use it at work.

Steve

Re: Length of hostname

Paul Sperry — Tue, 10 Dec 2002 16:43:18 GMT

I'd stick with 8 characters.

Re: Length of hostname

MANOJ SRIVASTAVA — Tue, 10 Dec 2002 17:03:23 GMT

Hi

you can take help from this thread

http://bizforums.itrc.hp.com/cm/QuestionAnswer/1,,0xe90957bd90a9d611abdb0090277a778c,00.html
"The answer for your question can be found from:
# man hostname
The max. limit will be defined in /usr/include/sys/param.h with the parameter - MAXHOSTNAMELEN. This is 64.

However, It is strongly recommended to keep your hostname up to 8 characters. Because the UUCP nodename is restricted to 8 characters and it automatically accepts the value from the set hostname. "

Manoj Srivastava

Re: Length of hostname

Shannon Petry — Tue, 10 Dec 2002 17:28:48 GMT

For compatability sake with other systems, no matter how long the OS states the hostname can be you do not want to exceed 8 characters.

Even some of the newer systems coming out have hard limite built in to help the windows people conform to the standards, instead of defining their own. again........

if you need long names, setup DNS and make good domain/sub-domain names. This way legacy systems and systems that support only 8 characters can still function.
Here are a few systems not supporting more than 8 characters.
OS/400, MVS, WinNT3.5, Windows 3.1, DOS, MacOS less than 9, SCO Unix, Most Unices older than 4 years.

Regards,
Shannon

Re: Length of hostname

Juan Gonzalez_2 — Tue, 10 Dec 2002 17:48:24 GMT

Thanks to everyone information for all the good feed back.