[plug] 64 Bit Upgrade of Ubuntu

[Tim]

On 15 May 2011 12:12, Dion Curchin <tenzero at iinet.net.au> wrote:
> I do have /home on its own partition and I had thought of fetching a dpkg
> -get-selections to help restore from a clean install.
>
> I had not thought to back up and selectively recover /etc and /var.
>
> I get backing up and comparing /etc now that I think about it. Although /etc
> is holding configuration type information which I can't see a reason it
> would change between 32 & 64 bit. So I would only really be looking at
> recovering post install customisations to /etc. Is that correct?

Correct. And if you had backed up the debconf database, and restored
it at the correct time, then anything in /etc/ that's manged by
debconf should be correct.

>
> However and this shows a gap in my knowledge, but what could be in /var that
> is worth keeping? Apart from maybe logs.

/var can contain mail, databases.
http://www.pathname.com/fhs/pub/fhs-2.3.html#THEVARHIERARCHY

It's really /var/lib and /var/mail (/var/local /var/opt if they exist)
that are needed.
Any application that works with data files for the whole system (so
not just a single user) will usually use /var/lib to store that data.
This is so /usr can be mounted read only. On my systems, the things
I'd need out of /var/lib could include mailman lists, mysql/pgsql
databases, ldap databases just to name a few.
On a desktop system, you might find that there is nothing in there you need.

Tim

-- 
Timothy White - Somewhere in Australia