Re: [Evolution] Notes on Data migration Evolution 2.24.5 to 3.4.3

[Pete Biggs <pete biggs org uk>]

On Tue, 2012-08-07 at 13:24 -0600, Brian A Anderson wrote:
> Attached is the file notes containing my notes about the migration of
> Evolution data from 2.24.5 to 3.4.3.
> The basics of this file is the procedure to migrate data (not a complete
> configuration) from 2.24.5 to 3.4.3.    
> The data can be merged into already existing data running under 3.4.3.

Thanks for your notes on how you did it.  A couple of observations, and
in no way is this a criticism of your method.

First, I'm always very wary of playing around with Evolution's private
files (i.e. the ones under .local) - if you know what you are doing,
then it will probably be fine, and Evolution will try and cope with
inconsistencies introduced by altering files manually.  However, that
may not always be the case, and naive tinkering with those files may
cause data loss.  At the very least, when you say "shut evolution down",
you should make sure it is fully terminated using the command "evolution
--force-shutdown" to make sure there is nothing hanging around that
might introduce inconsistencies.

Second, as I've said a few times on this list before [1], the easiest
way of importing files from the old mbox format (if the automatic
translation doesn't work) is to make a copy of the old Evolution data
tree somewhere, find which directory all the mbox files are held in,
then create an account within Evolution of type "Standard Unix mbox
spool directory" and point the path at the directory containing the mbox
files.  The new account in Evolution will then contain all your old
mail.  You can then copy all the mail you want from that account into
the normal folders in Evolution.  This will ensure that all Evolution's
files are kept internally consistent.  Once you've copied all the mail
over, you can remove the account in Evolution.

But the beauty of Unix is that in general there is more than one way to
achieve a result - all methods are equally valid, just use the one that
works best for you.


> <Begin editorial mode>
> The key things that I learned here are;
> 1.  the two different versions of Evolution had two different mailbox
> styles. 
> 2.  The two versions of Evolution were not compatible.
> 3.  the evolution of Evolution had abandoned those with older systems.
>     Cynical but apparently true.

I don't think that's entirely true or fair. Did you give Evolution a
chance to upgrade your data structure?  i.e. did you start Evolution
with the old files in their original place rather than trying to do it
through the backup files? 

> Backwards compatibility is very important.
> The useful migration of data is not as simple as constantly updating
> your mailsystem as each version comes out.

Evolution is probably one of the best applications I know for upgrading
internal storage formats - it is quick, unfussy and accurate.  Most of
the time you don't even know it's happened.  It's a damn sight better
than "apply this sql patch, run this program, apply next sql patch,
delete the following directories" etc. etc. that I often come across.


> Some versions may not offer a real reason to migrate.
> I for one don't want to become a slave to updates like Windows users
> are a slave to updates.

But you *must* install updates for any operating system - they fix bugs
and, most importantly, they fix security holes.  It just simply should
not be optional to install updates.

> Rather I look at my Linux environment the same way I looked at HP-UX
> as a stable working environment that changed when we had to.  Not just
> as HP came out with new versions.   When our old machines became HP
> Obsolete then we were forced to move.

In that case, with all due respect, why are you using Fedora!  Fedora
versions are obsoleted after about a year - which means that all
updates, including security ones, will cease.  And you really, really
don't want to run a Linux system without security updates.  If you want
stability, then use a RHEL clone such as CentOS or ScientificLinux -
they will guarantee support for about 5 years after EoL of a particular
version - but you still have to install updates.

P.

[1] e.g. https://mail.gnome.org/archives/evolution-list/2012-June/msg00042.html