Hi All,

My first post - try to be kind!

I have two RedHat servers:
Old server: RedHat 8.?, kernel: 2.4.18-26.8.0
New Server: RedHat 9, kernel: 2.4.20-20.9

The new server will be a replacement E-mail server for the old one.
My question: what is the most efficient way to copy all of the user
accounts (there are lots) from the old server to the new one?

TIA,
Geoff

1) rsync the user home directories to new computer.
2) merge in the old /etc/passwd and /etc/shadow into the new

If you have special setup for permissions such as in /etc/group or /etc/sudoers, these too will have to be merged.

Presumably you have not setup any new users on the new server which may conflict namewise or UIDwise from those on the old server.

Chris

Hi Chris,
Thanks for the reply. I already tared up and pulled over the home directories.
There are no new users on the new server - it is a virgin machine.

It is /etc/passwd and /etc/shadow I was worried about. Exactly how do I merge them?
Could I just replace the copies on the new server with those from the old? Seems too easy!

Cheers,
Geoff.

Linux rules

Since you said it's replacing an e-mail server, you will probably also want to copy over /var/spool/mail/ (unless your incoming mail ends up somewhere else).

Hi kjcole,
I already copied over /var/spool/mail too.

Still need to know though:
can I just copy /etc/passwd and /etc/shadow from the old server to the new one?

Cheers,
Geoff.

The thing to worry about when copying over the old /etc/passwd and /etc/shadow (and don't forget /etc/group) is that newer versions of packages sometimes need new user/group info. The installation will create those for you, but if you copy your old /etc/passwd et al, you'll wipe out any changes that specific packages have added or changed... Hence, the recommendation to merge rather than overwrite.

You could just append your old to your new, and sort them. Then edit out the duplicates...

Sorry I have not gotten back to this post, but I think kjcole explains it well. But to throw in my 2 cents which may help if you are not finished yet, here goes:

These are simply ascii files. In the best case situation as kjcole says, you could simply replace the files and yes it is just that simple, but to repeat, a new version has likely changed/added system users and groups. In order to merge, you simply add the lines you need from the old files into the new files. Appending and sorting will work, but should a difference exist for the same user or group, I'ld probably take the new one, just because. The only other caveat that comes to me at the moment is potential encription methods for the password in /etc/shadow. There are different methods out there in the wild and I do not know for a fact that RH9 and RH8 use the same method -- but here I am just being a worrywart.

Let us know how it went.

Regarding the previous post by fsbooks...

Oops. Right. If you get two lines which are ALMOST duplicates, and you sort the file, you won't necessarily be able to readily identify which line is the newest line, without going back to the original files. While my earlier recommendation is relatively quick, it's not without pitfalls.