Length of hostname

[Juan Gonzalez_2]

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

[Christopher Caldwell]

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 */

[Ian Kidd_1]

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.

[harry d brown jr]

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

[Scott Van Kalken · Accepted solution]

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.

[Ravi_8]

Hi,

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

[Jean-Louis Phelix]

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.

[donne007]

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

[Ravi_8]

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.

[Steven E. Protter]

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.

Steve

[Steven E. Protter]

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

[Paul Sperry]

I'd stick with 8 characters.

[MANOJ SRIVASTAVA]

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

[Shannon Petry]

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

[Juan Gonzalez_2]

Thanks to everyone information for all the good feed back.