On Solaris 10 the value in the /etc/nodename file is sufficient for setting the hostname of the system.
The hostname of a solaris system needs a change in the following files. So replace the old hostname with the new one in these file. Do not try to comment out as this may lead to some boot time errors.
- /etc/inet/ipnodes (Solaris 10 or later)
In order to change the hostname and nodename for the current session run:
uname -S new_hostname
Next change the savecore-dir (Solaris 7 or later)
dumpadm -s /var/crash/`uname -n`
Finally restart the syslog service to log messages using the new hostname.
Courtsey – http://www.princeton.edu/~unix/Solaris/troubleshoot/hostname-change.html