a confusion regarding package updates

[Alan Pope]

On 19 January 2011 13:09, Tapas Mishra <mightydreams at gmail.com> wrote:
> When it says intelligently handles changing dependencies with new
> version of packages then what does it mean?
> Is it referring to moving from 10.04 to 10.10?
>

Yes and no.

apt-get dist-upgrade _can_ be used as one of the tools to get you from
10.04 to 10.10. However so long as you haven't changed your
sources.list, you'll stay on whatever release you're currently on.

> "New versions of currently installed packages that cannot be upgraded
> without changing the install status of another package will be left at
> their current version."
>
> What is install status?
>

Lets say you have a package called foo-1.0 and there is a new version
called foo-1.1 which fixes some bugs, but foo-1.1 requires some extra
package called bar-0.5. If you do "apt-get upgrade" you will _not_
install bar-0.5 and thus foo-1.1 will be prevented from installing. if
you do "apt-get dist-upgrade" then it will.

> If some thing similar happens I am not in a position to recover back
> (in terms of time).
> So I am a bit fearing to use apt-get upgrade on the server in question.
>

apt-get upgrade and dist-upgrade are pretty safe.

Al.