RH 7.1 atd suddenly fails at startup...what happened?

[Lennart Sorensen]

On Thu, Feb 26, 2004 at 08:24:32PM -0500, Russ Heaton wrote:
> I was afraid it might come to that.   Thank God this is not a critical
> machine.  I've never been able to gracefully/cleanly upgrade a Linux
> machine.  It seems that you have to have an extreme awareness of where
> everything is placed when you first install an app, so that when you
> upgrade you know what to save.  If it was just a matter of saving your
> /etc and /home, it wouldn't be so bad, plus there are issues of what
> version libc you're upgrading from/to and so on and so forth, plus
> re-installing each app. one by one.  It's not that easy when you only
> occasionally venture into the Linux world.   In any event, I guess
> that's what I'm gonna have to do.  I'd kind of like to try Debian, but
> there don't really seem to be many books on the subject, where as
> there seem to be lots of them for RedHat, so I'll probably go for the
> current version of RedHat.

Books tend to be obsolete very quickly (although I guess with Debian's
release cycle it wouldn't be so big a deal).  I have seen books on
debian in the past.  www.debian.org does have quite a lot of
documentation.  #Debian on irc.debian.org has a lot of very active and
helpful people (including me sometimes) answering questions about how to
do things.  Every package has it's documentation (and often a debian
specific README) in /usr/share/doc/packagename/ that can be very helpful
in figuring out how to set things up.

Basic commands needed to run a debian system efficiently:

apt-get update - updates list of available packages on archvies listed
		in the /etc/apt/sources.list config file.
apt-cache search keyword - finds packages that do what you want.
apt-cache show packagename - shows description of a package
apt-get install packagename - downloads and installs packagename (and
		dependancies)
apt-get remove packagename - removes a package.
apt-get --purge remove packagename - removes package files and config
		files.
apt-get dist-upgrade - upgrades installed packages to newest avilable
		version (within current release)
apt-get install --reinstall packagename - reinstalls a package (in case
		you overwrote some of its files or did something else
		wrong).
tasksel - installs a group of packages that do a certain task.  mostly
		useful for the initial install.  dselect is really never
		useful anymore (it is a bad interface when the system
		hits 15000 available packages.  It was ok for 3000).
update-alternatives --config command - change which of multiple
		available choices provide a given command (ie vi,
		editor, x-window-manager, tar, gs, etc.)  All versions
		of a command are available usually as
		command-specificversion or command.specific version (ie
		gs-esp and gs-gnu, or nvi and vim in the case of vi
		providers.)
dpkg-reconfigure packagename - asks the questions asked during install
		again and updates settings for a package.
		xserver-xfree86 for example to change X settings.

aptitude is an ncurses application that provides a menu interface to do
all the above (and then some, like auto removal of dependancies when
nothing else requires them (if they were automatically installed of
course).

All config files go in /etc, either as /etc/packageconfigfile or
/etc/packagename/configfiles.  Some defaults for things launched by init
go in /etc/defaults/packagename.

Time to stop writing before I write a Debian user guide in a single
email.

Lennart Sorensen
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