Re: [courier-users] Ubuntu and Courier upgrade

[Sam V. <mr...@co...>]

Lindsay Haisley writes:

> I'm in a bit of a corner. I'm running Courier 0.68.2 on Ubuntu 16.04
> with esb support so that security on it is good. I have a lot of fairly
> advanced customer-managed mail management features, some of them
> depending on maildrop and various other characterisics of this version
> of Courier (including the use of v4 addresses in trace headers of the
> form "::ffff:a.b.c.d" hybrid v4/v6 format). The version of Courier in
> the next available release is 0.78.0-2ubuntu2.
>
> For a number of reasons I'll need to update the server OS fairly soon,
> and will need to keep basic mail functions working for customers,
> including the use of DEFAULTDELIVERY="| /usr/bin/maildrop" in courierd,
> and all maildrop features.
>
> Please advise me what as to what I'll need to watch out for, and any
> suggestions to make this transition go smoothly will be VERY welcome.

You want to build a new server, rather than to try to upgrade the existing  
server in place.

I don't have a working Ubuntu server at the moment, but I did have one last  
year, and I updated it from 20 to 22. I don't have a lot of confidence in  
Ubuntu's upgrade process. It apparently starts with the currently running  
system, live, just like that, then installs all updated packages, one by  
one, then reboots.

That's just a recipe for disaster. Fedora does this right: downloads  
everything, reboots into single user mode, updates everything, then reboots  
into the updated system. It does seem to bring up more stuff than it needs  
to bring up, but that's still much safer.

If I was in this situation I would build a new server, take my time with it,  
test it, kick the tires on it, then take the downtime to copy over all the  
mailboxes to the new server, then bring it up in place of the old one.