Autor: Jeroen van Aart Data: A: exim-users Assumpte: Re: [exim] Immediate bounce after mail is received
Jens Hoffrichter wrote: > Generally speaking, it is of course better to keep at an actual
> release, but as so often, the need of having an uninterrupted system
> with as few downtimes as possible, is very big. And as an upgrade
I understand your sentiment, but it really shouldn't affect anything. I
did an upgrade from exim 3.x to exim 4.x on a live system with as much
downtime as it took to stop exim 3.x and start exim 4.x (aka exim3 and
exim4 on debian), which was under a minute, during lunchtime, and no one
noticed.
What I did was to have a carefully grafted config file where every
custom configuration present in 3.x was added in 4.x with its specific
syntax. Since the syntax of the config files had changed considerably
between the 2 versions. I also made sure to keep the old one around for
a while and be able to quickly revert back in case things would break.
In your case there is no syntax change. If you really want to be careful
then create a clone and try out the new version.
> issues pressing an upgrade, or a general systems upgrade. But the
> latter one is seldomly done, the software remains old, if not ancient
With that idea your system at some point may become so ancient that any
upgrade will be very painful and require considerable downtime. What if
newer exims are compiled against a newer libc? Or what if you try and
compile it yourself only to find out it can't compile against the
version of libc you have.
I have experienced issues with software which would work with (fake
versions as I forgot the particulars) libc-2.95.5 but would fail with
libc-2.95.2. Even if I faked the compilation procedure by creating a
libc-2.95.5 symlink. The application, firefox for example, would develop
mysterious gui issues. Apparently at least my "stable" libc version had
some bugs necessitating an upgrade.
Admitted, this was my own handcrafted linux from scratch install. It
prompted me to migrate to debian. ;-) But you get the idea...