[lug] Moving Users to New Server?

[Kyle Moore]

I don't know of any documentation but I just got done doing this with a
big HP server. In a nutshell, here is what I did. Data should be
separate from the OS so most of it can be done via backup/restore. I
brought the new server up with another IP to install and configure the
OS and database. Pretty much everything you need to change that won't be
on backup is in /etc. In my situation there were a few things in var but
you probably won't have that.

All of the config files were brought over or customized (we moved up in
OS and db versions as well as new hardware) before the migration date.
Filesystems that could be "frozen" before the migration date were also
moved over. I switched things over on a Friday night / Saturday morning. 

Friday night I got everyone off of the system early, shut down cron and
did a backup of just the data that wasn't already on the system as well
as any configuration files that might have changed. After that backup
was done, our operators ran the normal full backup. Saturday morning,
both backups kept onsite, I switched IPs and hostname on the old server
and shut it down but didn't bring it back up. Then I switched the IPs
and hostname on the new server to match that of the old. After the new
server was back up and it's integrity verified, the old server was
brought up and verified.

The total downtime was pretty minimal and could have been much less. We
had downtime planned because of major database layout changes I wanted
to make to improve efficiency. Also, make sure the /etc/hosts file
thinks the server is who it should be. We don't use DNS or NIS so what
hosts says goes. I think the key to a smooth switch is to keep the same
IPs and hostname. The most important aspect to a migration is knowing
your system. The better you know it, the better the chance you won't
miss anything. 

If you have any specific questions I will be happy to try to help you
with them.


"Lee, David P" wrote:
> 
> Hello Lugs
> 
> I am in the process of replacing an older server with a new one.  Is there
> any documentation/procedure in doing this task?
> Items of concern: user accounts, user passwords, mail and personal home
> pages.
> 
> Old server: Red Hat Linux release 6.0 (Hedwig) Kernel 2.2.5-22 on an i686,
> sendmail 8.9.3
> 
> New Server: Red Hat Linux release 6.2  Kernel 2.2.14 on an i686, sendmail
> 8.11
> 
> Thanks in advance!
> 
> David
> 
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-- 

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Kyle Moore