[CentOS] Re: Contemplating Move -- [OT] Fedora Core

[Les Mikesell]

On Thu, 2005-08-18 at 00:41, Mike McCarty wrote:
> > 
> > FC3 is at the end of the cycle where the new bugs in the new code
> 
> Couldn't this same argument be made for FC2? I've put myself on the
> Legacy update notification, and have used yum over a dozen times,
> but not downloaded one single fix.

FC2 won't break just because its old, but on the other hand no
one is very interested in maintaining it.  The whole purpose
of the FC distributions is to roll out new stuff and backporting
fixes into old versions isn't fun or interesting.

> > That doesn't make much sense. If you care about your data, make
> > backups that will survive whatever happens to the machine.  External
> > hard drives, CD and DVD writers are all inexpensive and suitable
> > for this.
> 
> Certainly, the data are backed up. It's the hassle of re-installation
> of all the packages and re-creating the work environment. The actual
> CVS repository is not on my machine. It's my stuff, not the company
> I'm contracting for, that I'm concerned about. I don't want 2-4 days
> downtime while I try to reconfigure.

If you keep a copy of your home directory, a snapshot of /etc and
copies of anything you've installed that didn't come from the
distribution you should be able to be up on a new installation
about as fast as you can copy it back.  You shouldn't actually
copy most of the files in /etc back to a different distribution
but they are handy for reference if you forget how something
was previously configured.

> Ah, there's the rub. Knowing *what* to back up is the issue.
> It appears that every version of *NIX has a different list of
> what need backup. Clearly on FCx one needs to back up /home/...
> probably also /etc/... and /var/... Or does one? Much of the
> stuff in /etc/... is also stuff simply used to configure
> GNOME, and whatnot. Yes, just go ahead, get it all. It's only
> something like 60MB on my machine (/etc/...). But how much
> of it do I need to restore?

If you want to reconstruct exactly what you had before (say
after replacing a bad drive) you could copy it all back. But
if you are updating to a newer or different distribution you
only want to duplicate the changes you had done yourself.  The
longer you go between updates the harder this is until you
learn to plan for it because you'll forget all the little
things you've added and changed.  You should log all the
changes you make and why you made them.  Packages in the
distribution or extras repository are as simple as 'yum install ..."
to grab if you miss them in the initial setup.  However, if you pick
up rpm packages that aren't included in you should keep copies
and note the location to check for updated versions.  If you
compile anything from source yourself that needs more than the
usual "./configure; make; make install" to build, you should save
the commands in a script that you can run again to repeat the
procedure later.

> I plunked down $50 USD last weekend
> on a book on Linux administration, which looks pretty good.
> But a 40 page chapter on backup (entirely too much of which
> was spent on explaining why one should back up) never even
> mentioned how to go about installing a new version of Linux
> and getting going again.

The process is much more complicated on multiuser systems where
the admin may not know everything that users have added for
themselves and what programs must continue to work.  Often you
have to time those updates to match hardware changes so you can
build everything on a new box and test it while still keeping
the old one in production until you are sure it all works. On
a single user box all you have to do is copy your own files back
and re-install any nonstandard programs.  

> Complete disaster recovery (I
> didn't need that, it's the same for every system) and
> general backup were considered. But not much else.

There is not a generic way to keep settings while going from
one distribution to another or even one distro version to
the next.  FC/RHEL are moderately good about upgrading
themselves but it is still safer to do a clean install
and put your stuff back.  Or, you can compromise by keeping
/home on its own partition and not formatting it during
the next install.   

> Actually, I'd prefer that they not change. I tried FC4, and
> had problems with finding where several things moved to. They
> changed the menu layout. I don't need that. I just want a computer
> which works. Having to learn all over again where to find
> the system configuration widgets is undesireable.

Centos4 sounds like a good choice then.

-- 
  Les Mikesell
   lesmikesell at gmail.com