a confusion regarding package updates

[Tapas Mishra]

On Wed, Jan 19, 2011 at 7:26 PM, Alan Pope <popey at ubuntu.com> wrote:
> 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.

Hmmm, I remember a long time back some faulty way of upgrade by me
had changed the sources.list file.
That time I had not touched manually the sources.list file so is this
same case when you
do a apt-get dist-upgrade (i.e. the script changes the sources.list
when a new release is available)
or it will ask the user to proceed or not to and then upgrade only new
packages (and not the OS itself).

>> "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.
Ok this is helpful.I feel in man pages not only the information but if
simple  explanations with some test cases or common usage scenarios
are also given then reading them will be quite useful.Consider this as
a  suggestion  to incorporate(if possible) in future releases.
You may consider having a separate package which can install examples
for man pages (if ISO size is a constraint).

>> 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.
Ok.

-- 
Thanks
Tapas