Keep in mind that Debian is a work-in-progress, meaning
that as holes are found and bugs are killed in the stable
distribution, a whole new world is developing on the UNSTABLE
distribution. If you need something from 'unstable' go
ahead and try it -- just don't gamble more than you can afford to lose,
right? Venturing into UNSTABLE is fine if you
don't mind being on the "front lines" so to speak. Most of us stick
with the stable distribution, which has no new gizmos
being created; only patches and fixes are added to the stable
release. You might occasionally want to delve into
UNSTABLE territory, for some new functionality that's
not available in the stodgy, old, stable area. It's up to you, but
don't expect a refund if something breaks -- it's called
UNSTABLE for a reason!
Starting in 2001 a new distribution of Debian is available.
It is called testing, and it covers the ground
between stable and UNSTABLE.
Testing is made of packages that have survived 14 days in unstable
without breaking. Major life-threatening bugs are thus solved before
making their way into testing. However, that also means that
security upgrades are also at least 14 days behind schedule...
However if your version of
apt supports it ( >= 0.5 ), there is a
very easy way to follow multiple distributions, it is
called pinning:
You must modify /etc/apt/preferences and
add:
1 Package: *
2 Pin: release a=stable
3 Pin-Priority: 900
4
5 Package: *
6 Pin: release a=testing
7 Pin-Priority: -10
8 |
then you must add lines for
both stable
and testing to your
/etc/apt/sources.list
and do an
apt-get update which will download
the usual files
twice, one for each
distribution.
After this, you can use the -t option to
choose which distribution you want to get packages from:
# apt-get -t testing install sgmltools2
|
The
Pin-Priority fields ensure that unless you
specifiy it manually, all packages will be taken from the
stable distribution (of course, dependencies are always met,
so you might have to download more than one package from
testing)
If you're running a live server, where any uncertainty or
instability would be a definite liability,
definitely shy away from
UNSTABLE or even testing
unless you enjoy soothing the frazzled nerves
of management, and their paying customers, and your spouse,
who keeps asking why you're always looking for a new job.
So you've got your Debian system humming -- you don't need to
let it fall behind! You can easily stay up-to-date with the
latest security patches, any bug fixes and an occasional
enhancement. That's the beauty of apt.
Once sources.list is set up and you're online,
first
to refresh the list of available packages -- if new things are
available, that is how your Debian system will learn of it --
and then simply
which downloads, configures and then replaces any packages you've
already got that have been tweaked. You'll probably want to do it
periodically, to squash bugs and plug security holes.
" NOTE that the Debian gurus work like the dickens to see to it
that your settings are not clobbered
when you upgrade a package or two. You may have spent a month
getting exim or inetd to hum
your very own tune, and heaven help the
miscreant who clobbers your settings, right? Sometimes there's
enough of a difference between what you've been running (the old
version) and the upgrade to be installed (the new version) that
the old settings may not be usable by the new program; in this
unusual case, apt informs you that
your old settings are being saved,
and in order for the new program to
function the way you want it to, you'll have to migrate your
settings by hand. But this is rare -- usually, your settings
stay right where you put them and you'd hardly ever know
anything had improved.
"
 | All this happens without having to restart. (For Mac and Windows
people -- imagine leaving your computer up for two MONTHS! It's
awesome!)
|
Once you're online, it's easy
to install new packages you're interested in;
simply do something like
# apt-get install vim traceroute mysql-server mysql-client
# apt-get install logcheck
|
to download, configure and install whichever packages you want.
" Where does apt put all this stuff it downloads? The
"cache" is located under /var/cache/apt/;
there's a 'table-of-contents' file there called
pkgcache.bin
(and if you're set up to also get source-code packages,
you'll also have srcpkgcache.bin) and the actual
*.deb package files are in
/var/cache/apt/archives/.
"