Re: Linux Update Experience

On 2020-05-28 14:36:34 +0000, Zwettler Markus (OIZ) wrote:
> I'm not talking about this specific bug or its resolution.
>
> I want to talk about the Linux update problem in general.
>
> Anyone updating Linux might get such nerving dependency troubles.

In my experience (having administrated Linux servers for 25 years),
dependency troubles outside of major updates are rare. But of course if
you do that long enough with enough different systems you will run into
one sooner or later.

Some ways to minimize the frequency of such troubles:

* Use a base distribution with a lot of packages. RHEL has a lot fewer
packages than Debian, so when we used RHEL (we still have a few
servers) we used external repositories (RPMForge, EPEL, ...) a lot
more. Some of those external repos may not be as well maintained as
the base distro and of course they may not coordinate with each other.
So more external repos mean a higher risk of conflicts.

* Use specialized systems. In the 90's servers were big and expensive,
so we had few of them and each was running a lot of different
services. Planning an upgrade took months. These days we use (mostly)
VMs, each of which is running only one service. That greatly reduces
the number or packages installed and the number of external repos,
thus reducing the potential for conflicts.

* Update frequently. That reduces the risk of needing a package which
has since been deleted from a repo, but more importantly it makes it
easier to pinpoint the cause of a conflict.

When a conflict does occur. being familiar with the packaging system
helps a lot. Sometimes just uninstalling a few packages helps. Sometimes
something in a repo has changed and you need to change the configuration
to match (as has apparently happened here), so being on relevant
announce-lists of having the URL of the repo website handy helps.
Sometimes you can force installation (althought that will often cause
problems later). In some cases I built my own packages.

hp

--
_ | Peter J. Holzer | Story must make more sense than reality.
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| | | hjp(at)hjp(dot)at | -- Charles Stross, "Creative writing
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