[CentOS] Re: Copying user accounts (passwords) to another server

[Walt Reed]

On Wed, Nov 29, 2006 at 12:46:13PM -0800, Kevan Benson said:
> On Wednesday 29 November 2006 05:43, Walt Reed wrote:
> > On Wed, Nov 29, 2006 at 01:31:48PM -0000, Nigel Kendrick said:
> > > I am doing a server swap out tomorrow and wondered if there was a utility
> > > that will copy user account details and their current passwords from one
> > > server to another (both CentOS 4) - there's only about 15 to do so it's
> > > not a major issue.
> >
> > Rsync and scp are your friend.
> >
> > You can either cut and paste the user info from the /etc/passwd, shadow,
> > and group files manually, or copy the entire files which wiill also copy
> > over all the system accounts (root password and such):
> >
> > cd /etc
> > scp -p passwd shadow group newserver:/etc
> >
> > Then of course you will probably need to copy the user home directories
> > over:
> >
> > cd /home
> > rsync -aze ssh * newserver:/home
> 
> It's worth noting that if you use external packages (rpmforge, kbsingh), that 
> some packages may create users without a set UID (as the core packages seem 
> to have), and if already installed on the new system, it might be using a 
> different UID.  In these cases, you should either copy regular user portions 
> of the files only, or take a careful look at a diff between the old and new 
> files to ensure there are no problems.
> 
> This caused me a few minutes of confusion with clamav/clamd (specifically the 
> milter socket) which had an incorrect owner after passwd sync on a mail 
> server migration.

Ya, that is annoying.

When building the "replacement" server, it can help to sync / add
accounts before all the third-party crap goes on. We do it as part of
the kickstart %post scripts. Kickstart from pxe-boot is awesome -
especially on HP servers... :-) Once a machine is installed in the rack
and powered up for the first time, it's online and usable with all the
packages we need, preconfigured, in about 15 minutes.