Re: a few Qs about debian's apt
Woon Wai Keen @ doubleukay.com (<firstname.lastname@example.org>) wrote:
> a friend of mine has some questions regarding debian. hope you guys
> could help me answer them :)
> 1) does 'apt-get upgrade' upgrades:
> i) the kernel,
If the kernel was installed through package management it will be
upgraded if a security update is available. This happend some months
ago. However, one update made the new version incompatible to modules
compiled for the old version, so the package name was changed (e.g.
kernel-image-2.4.18-686 became kernel-image-2.4.18-1-686). In that case
the kernel was not upgraded automatically. The package management also
does not know about the installation kernel, although you can change
this by installing the package after installation.
The package management will warn and ask you if the module direcotry of
some kernel image is to be overwritten and warn you if you are going to
replace the image for the kernel currently running.
I think apt will not automatically upgrade the kernel if the kernel
version number changes (e.g. from 2.4.21 to 2.4.22).
> ii) base apps
Yes. (I assume that "base apps" only base apps installed through package
> iii) local apps (/usr/local)
No. As far as I know packages in Debian don't install anything to
/usr/local, so it is left untouched.
> 2) where does apt-get saves all it package information?
Apt stores information on packages sources in /var/lib/apt/lists. Apt is
a frontend to dpkg, which stores information in /var/lib/dpkg.
> 3) is there a way to just upgrade the local apps instead of all
> local/kernel/base at the same time? if so what is the apt-get
Local apps as in installed in /usr/local? See above.
> 4) what do we do if we need to synchronize the package information
> manually, say for some reason apt-get fails to include version
> information on newly installed package; it's still using the old
> version although the package has been overwritten by the latest
I don't know if that can happen, however in that case apt would think
the old version was still installed and try to upgrade it again, which
would probably solve the problem. Apt also has an reinstall option.
> how do debian define non-base apps? in the bsds, non-base apps which
> is called local apps are those not part of the vendor-approved base
> distribution. for example, apache13 is part of openbsd 3.4 base system
> while apache2 isn't so if were i to deploy apache2, it would be
> defined as local apps and be place in /usr/local. apache13, as
> opposed, is placed in /usr. getting back to debian, say for an
> application that is not part of debian base distribution, how do we go
> about getting apt-get to upgrade them, or does debian does not
> segregate the definitions of base/local apps?
If you install in manually in /usr/local (e.g. by compiling from source)
apt does not know about it and will leave it untouched. You can however
try to find some source for programs not included (or not included in a
recent version) in Debian that you can use through apt. See
<http://www.apt-get.org> or <http://www.backports.org> for more
information. Also note that Debian does not use a ports system like
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