Re: RH9 to ES Migration

[Rick Stevens <rstevens vitalstream com>]

Jeff Hogg wrote:
> Charles Braffett wrote:
>
> > So, if I do a clean install using the existing partitions, then copy the
> > old etc folder in, that should work?  BTW, I don't want to lose any file
> > structure nor data (several CVS stores running).  :)
> >
> > -----Original Message-----
> > From: redhat-install-list-bounces redhat com
> > [mailto:redhat-install-list-bounces redhat com] On Behalf Of Neil
> > McFadyen
> > Sent: Thursday, May 06, 2004 7:14 AM
> > To: Getting started with Red Hat Linux
> > Subject: Re: RH9 to ES Migration
> >
> > make a copy of /etc   it will have most of the settings you need
> >
> > Charles Braffett wrote:
> >
> >
> > > I have a production server running RH9 which I need to migrate to ES.
> > > Can someone give me step by step instructions on how to preserve all
> >
> >
> > the
> >
> > > settings?  (i.e. users, groups, IP bindings, route tables, apache
> >
> >
> > sites,
> >
> > > etc...)
>
> It's a bit more complicated than that unfortunately...  You'll need your 
> /home directory, and any active data directories in use by the 
> applications your currently using at least.  I can't guess where your 
> cvs data is being stored, you will need to determine that yourself. /etc 
> will take care of your network info and most of the settings for the 
> programs you have... but it may not be wise to simply paste it back in 
> on top of the new system, as some things may have changed after all. 
>  New hardware, and minor file format changes and such.  Basics like 
> ifcfg-eth0 are fairly stable, but you shouldnt try to re-use the 
> conf.module file for example.  Burn /etc and the data dirs onto a cd and 
> copy back just the files you need, not the whole mess I would say.   I 
> hope this helps a bit.

Actually, it's a bit more nasty than that.  An "upgrade" install
shouldn't destroy any user-created stuff.  A "clean install" WILL kill
stuff.

First, back up EVERYTHING and make sure your backup is good.  That's
VERY important.  In addition to that:

a) make copies of your /etc/passwd, /etc/shadow, and /etc/group files.

b) go through /etc/passwd and make sure you make backups of all of the
home directories listed in there.  Those are your users' home
directories.

c) if you're using stuff like CVS or SCCS or something of that nature,
make backups of your repositories.

d) if you're using databases of any kind (MySQL, PostgreSQL, whatever),
make backups of their data stores.

e) make backups of any application-related data you need including
configuration files and the like.

You can then do an "upgrade" installation.  That SHOULD leave all non-
system-related stuff alone, but you have two backups of the stuff you
need (the main backup and the individual backup) to recover from.  If
you do a "clean" install, then you can be guaranteed that everything
will get wiped out and you'll need to restore from one of the backups.
This means restoring your /etc/passwd, /etc/shadow and /etc/group files
(to recover your user names and passwords) and the home directories
related to /etc/passwd.  You'll also need to reinstall your databases,
repositories, applications and their data.

I'd try the "upgrade" first.  If that doesn't work, do the full install
and restore the stuff you need.  Either way, it's not trivial.

"Backups are your friends.  Make more friends regularly."
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- Rick Stevens, Senior Systems Engineer     rstevens vitalstream com -
- VitalStream, Inc.                       http://www.vitalstream.com -
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-            The gene pool could use a little chlorine.              -
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