Here's an old fashioned way of keeping passwords synchronized (pre-NIS):
1) Tell users to only change their passwords on one host (or their changes won't work.)
2) Build a SIMPLE script to copy /etc/passwd (and /etc/shadow) to all of the hosts.
3) Build a SIMPLE script to check if the passwd file (and shadow file if necessary) has changed since the last time this script was run.
Pseudo code follows:
if (testfile exists)
diff testfile /etc/passwd
if not identical
run script from line 2
cp /etc/passwd testfile
else
cp /etc/passwd testfile
fi
4) Take script of line 3 and make it a cron job to run every 1 minute.
[ Comment: Yes, a diff running once per minute may be taxing, but geez, telling people to wait two minutes for their changes to take effect will be annoying too. I've tried the "run this script" to change your passwd, and people forget to, or know too much about UNIX and outright ignore you. ]
5) For the ultra accurate, kick off script of line 3 on every boot up of the "passwd host" in line 1.
You could edit all six accounts from one host, and in one minute after you're done - all hosts are being updated for you. Obviously, there is room for improvement, like verifying the files arrived to each host, and so on.
When you get past 40 hosts, keeping tabs on these files gets downright annoying. Consider moving to NIS or LDAP services.
"Any sufficiently advanced technology can be indistinguishable from magic" Arthur C. Clarke. My corollary - "Any advanced technology can be crushed with a sufficently large enough rock."
