On Fri, Jan 29, 2010 at 11:22:04AM +0100, Peter Keel wrote:
Yes, but that's absolutely painless.
I also regret the times when Debian was only releasing every 3 years or so, however, the current release cycle is not that fast, you still have two years between upgrades, and obsolescence is usually announced one year ahead.
I still prefer Debian over Ubuntu, even installed minimally, because Debian has less "weight" (although it's increasing: I have for example seen with horror that I was touched by the python security bug, because Debian installed python for the ssh-blacklist package -- it's unfortunate those dependancies leak in ...).
Remember: the more packages you have installed, the more the administrative overhead will cost.
I suggest the following, after the upgrade:
sed -i s/etch/lenny/g /etc/apt/sources.list apt-get update apt-get dist-upgrade
- start aptitude, check if there are any Obsolete or locally installed packages, remove them, and possibly find new packages to replace them. If you don't do this, those packages might be a security hazard (or just an administrative cost).
- maybe use apt-get autoremove (but see below) to get rid of unnecessary installed packages (less packages == less work).
- maybe use deborphan to locate unused packages, and remove it.
It is always a good idea to read the release notes before upgrading (see http://www.debian.org/releases/stable/). There are many advices there for what to do BEFORE, DURING, and AFTER the upgrade.
Other ideas:
- I use OpenVZ as a fast, efficient, simple: in a word UNIX-ish virtualization plateform; keeping the host system as simple as possible, basically a hardware layer.
Thus non host updates can be tested first on a VZ copy; host updates can be attempted first on similar hardware, especially if you already have some sort of high availability in place.
- don't forget to check whether you have added any non standard sources.list entries, those packages are not supported by Debian on upgrades. Of course you haven't installed any package by hand with dpkg -i or converted with alien/rpm that you found on the Internet I hope :)
- if you use special administrative tricks (for example package diversions, package holds), be sure to check for them before and after upgrading.
- it is generally assumed that any local changes to the system will be done in /usr/local and never to installed packages themselves (diversions come handy here!). Locally installed software (in /usr/local or /opt) is usually not touched by system upgraded, don't forget to update it as necessary yourself.
- if you use aptitude, beware of the autoremove features.
- use FAI for easy service / system installation (class-based, reproductible)
For those who don't know, diversions are a way to tell the packaging system that when it updates a file, it should update it elsewhere. This paves the way for seemless patching and wrapper scripts in-place.
Holds are ways to tell the system to never touch (upgrade) a package. There are unfortunately two incompatible holds in Debian: apt/dpkg and aptitude.
Recommended books: The Debian system : concepts and techniques, 1-59327-069-0; Cahiers de l'Admin: Debian GNU/Linux (http://www.ouaza.com/livre/admin-debian/extrait-apt.pdf)