[CentOS] Move from FC6 to CentOS5

[Styma, Robert E (Robert)]

> >
> > This is one of those questions: it's doable, but if you need to ask,
> > probably not by you;-)
> >
> > It might also be possible to force Anaconda to do the upgrade.
> >
> > There is some probability > 0 that you will be left with 
> orphaned and
> > unsupported packages, depending on what you have installed.
> >
> 
> Thanks John.
> 
> Basically if you have done updates to the system.. you will have
> 'orphaned' packages. Fedora Core 5 and 6 kernel, glibc, (or other
> things) have higher rev's than what is in CentOS-5. The best fix is to
> do a backup of /etc and other config files, backup your /home
> /var/I_do_stuff_here partition and install a fresh CentOS-5
> 
A couple of suggestions for doing the fresh install and minimizing
some of the pain.  
1.  tar /etc to someplace safe.  While you cannot just restore the
files,
    you can use them as a reference.  There are pieces of /etc/passwd,
    /etc/shadow, /etc/samba/smbpasswd that you will want to copy to the
    new system to preserve users passwords.  Also your
/etc/samba/smb.conf
    file will probably just copy across.  (assuming you are running
samba).
    Other data such as that from /etc/resolv.conf will come in handy
when
    fixing the network configurations.
2.  Do rpm -qa > /some/safe/file.txt so you have a list of the packages
    installed on your FC6 machine.
3.  I am assuming your root partition is separate from user data in
places
    like /home.  If not, you will need to make sure you have a backup
    restore plan or the users get testy.  You will want a backup anyway
    just in case something goes haywire.  If /home is in a separate
    partition, you will be able to tell the installer to leave it alone.

If you are really fortunate, your root partition is on a separate
physical
drive.  Then you can stick a new drive in and do the install.  The old
drive
becomes a good fallback.

Just my 2 cents.  

Bob Styma