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Upgrading from RHEL v3 to v5

Jesse Fitzgerald [jesse at nursingnet.com]


Mon, 26 Mar 2007 06:41:07 -0500

[[[ Please do not send in text with "smart" quotes! And please use a proper .sig delimiter - two hyphens and a space followed by a newline! -- Kat ]]]

Hello all. I'm running Redhat Enterprise Linux version 3.0 with an active RHN subscription.

Linux 2.4.21-47.EL #1 SMP Wed Jul 5 20:30:36 EDT 2006 x86_64 x86_64 x86_64 GNU/Linux

I want to upgrade to version 5.0. I?m a bit anxious though. I only have a few users, but have spent a lot of time getting everything running well on my box. My question: If I install Red Hat Enterprise V5 using the upgrade option via the anaconda installer, will I loose any of my data or applications? I know that doing a clean wipe and reinstall is the BEST solution, but if possible I would like to upgrade.

Here is what I'm specifically concerned about loosing: Apache, MySql, PHP, Qmail, Vpopmail, and various other small applications (Webalizer, etc?). All of the above have been compiled from source. I'm also concerned about stuff in /usr /usr/home /etc and /var being overwritten.

I hope my questions aren't too silly. I'm a novice with basic administration experience. My server is not a mission critical commercial machine. Small variances caused by the upgrade would be easily tolerated.

Thanks in advance for any info you may have.

Kind regards,

- --Jesse :)

PS. Here's the partition information for my system if it helps.

more fstab
LABEL=/                 /                       ext3    defaults        1 1
LABEL=/boot             /boot                   ext3    defaults        1 2
none                    /dev/pts                devpts  gid=5,mode=620  0 0
none                    /proc                   proc    defaults        0 0
none                    /dev/shm                tmpfs   defaults        0 0
/dev/sda3               swap                    swap    defaults        0 0
/dev/cdrom              /mnt/cdrom              udf,iso9660
noauto,owner,kudzu,ro 0 0
-- 
Jesse Fitzgerald
GnuPG Key 0x99EEDF02
Download @ http://pgp.mit.edu/

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Thomas Adam [thomas.adam22 at gmail.com]


Mon, 26 Mar 2007 13:00:30 +0100

On Mon, 26 Mar 2007 06:41:07 -0500 Jesse Fitzgerald <jesse at nursingnet.com> wrote:

> I want to upgrade to version 5.0. I?m a bit anxious though. I only
> have a few users, but have spent a lot of time getting everything
> running well on my box. My question: If I install Red Hat Enterprise
> V5 using the upgrade option via the anaconda installer, will I loose
> any of my data or applications? I know that doing a clean wipe and
> reinstall is the BEST solution, but if possible I would like to
> upgrade.

Actually, it's not the best solution at all. In doing that you will invariably wipe out all manner of settings -- some of which you might not have realised to backup at all (hint: some application use /var as a dumping ground which tends to trick a number of people when they backup their configurations in an attempt to do a window-esque style of ""upgrading""; wholly wrong, IMO).

Upgrading will replace binaries in /usr, yes. That's a premise you except when you upgrade, of course. If you have custom binaries you yourself have compiled from source which install to /usr then you might be able to tell your package manager (rpm in this case) not to touch certain files -- you certainly can with apt under Debian for instance, but it's been some time since I last an RPM system with any great vigour.

> Here is what I?m specifically concerned about loosing:
> Apache, MySql, PHP, Qmail, Vpopmail, and various other small
> applications (Webalizer, etc?). All of the above have been compiled
> from source. I?m also concerned about stuff in /usr /usr/home /etc
> and /var being overwritten.

Well, as I mentioned above, stuff in /usr and /var will get overwritten. Full-stop. This is why you upgrade, after all. The best solution I can offer you is to backup the configuration files for all of the programs you've listed above, reinstall the compiled applications from source, and just have done with it.

This ought not to be much of an option though, assuming the compiled applications you yourself have installed haven't overwritten files which you might have previously installed via rpm. I.e., if you have apache installed then it will overwrite your custom package, and likewise, if any of the dependencies in the upgrade cause apache to be installed that too will overwrite your files.

This is where the advantage of installing to /usr/local (typically the default with PREFIX= or --prefix= depending on whether you use make or./configure respectively) comes in handy. It's policy for packages not to install files there. You may of course already meant /usr/local for your compiled applications; it's non-obvious from your descriptions, so I am taking you verbatim.

Oh, and as a parting comment, one of the reasons why people split /usr and /home onto separate partitions is also to make things like upgrading work easier -- i.e., not mounting /home is often beneficial so that nothing really can be deleted or overwritten, etc. (A poor example in this case, but the essence of it applies.)

-- Thomas Adam


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Thomas Adam [thomas.adam22 at gmail.com]


Mon, 26 Mar 2007 14:15:25 +0100

Begin forwarded message:

Date: Mon, 26 Mar 2007 07:42:05 -0500
From: Jesse Fitzgerald <jesse@nursingnet.com>
To: TAG <tag@lists.linuxgazette.net>
To: Thomas Adam <thomas.adam22 at gmail.com>
Subject: Re: [TAG] Upgrading from RHEL v3 to v5

Thomas,

Thanks for the advice. I figured as much. I think I'm gonna just stick with v3 for now since Red Hat is gonna support it for a few more years, although I cant seem to it's end-of-life date.

Thanks again,

Jesse :)

-- 
Jesse Fitzgerald
GnuPG Key 0x99EEDF02
Download @ http://pgp.mit.edu/

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=?iso-8859-15?Q?Ren=E9?= Pfeiffer [lynx at luchs.at]


Mon, 26 Mar 2007 17:30:41 +0200

On Mar 26, 2007 at 1300 +0100, Thomas Adam appeared and said:

> On Mon, 26 Mar 2007 06:41:07 -0500
> Jesse Fitzgerald <jesse at nursingnet.com> wrote:
> 
> > I want to upgrade to version 5.0. I?m a bit anxious though. I only
> > have a few users, but have spent a lot of time getting everything
> > running well on my box. My question: If I install Red Hat Enterprise
> > V5 using the upgrade option via the anaconda installer, will I loose
> > any of my data or applications? I know that doing a clean wipe and
> > reinstall is the BEST solution, but if possible I would like to
> > upgrade.
> 
> Actually, it's not the best solution at all.  In doing that you will
> invariably wipe out all manner of settings -- some of which you might
> not have realised to backup at all (hint:  some application use /var as
> a dumping ground which tends to trick a number of people when they
> backup their configurations in an attempt to do a window-esque style of
> ""upgrading""; wholly wrong, IMO). [...]

I agree with Thomas concerning the reinstall of the whole system. It's not automatically the best solution. Another way is to move the system to a different place where you can safely try the upgrade. You could backup everything and recover it onto different hardware (a spare PC or something like that) or into a virtualisation environment (be it VMware, Xen, whatever you like best). By doing this you gain

 - an additional backup of your installation with all the data
 - experience in recovering a system from backups
 - and a testing environment where you can safely check what the
   Anaconda installer will do when upgrading.
From my experience I'd say that you have to check all important services after the upgrade and possibly recompile some applications due to the upgraded system libraries. The distributions usually leave things in /usr/local alone, so they should be safe. However the word "should" isn't something you should rely on.

Best, René


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