Downgrade debian 10 buster to Ubuntu 18.04 on same server - simple backup restore?

Hello, I need to take a working ISPConfig 3.1 latest with patch3 on debian 10 buster which has a hundred or so dns entries, a hundred website entries and a hundred email accounts and mailboxes - and change buster to Ubuntu 18.04 LTS.

This might bo smoothly just changing the apt sources and doing it slowly - which is what I am going to try.

My question is - will a backup of ispconfig3 on buster contain all the data (the above-mentioned entries) and can it be restpored into a freshly-built same type of server on Ubuntu 18.04 - using the same software - apache2 worker, dovecot, postfix mariadb, etc?

Would you recommend doing any kind of ftp download (for example of apaceh2 vhost files or mbox for mail or bind9) etc? in case I can't restore from the backup?

I will do a full mysql dump and also by database dumps.

Thanks for any tips on this - I have to do the downgrade from buster to ubuntu 18.04 .

 

I don't think there's much, if anything, in the way of differences between ubuntu and Debian, but I would be very wary of switching anything in this way. it's possible that if you backup of all /etc /opt et al, and restore them you would be ok, but then again, you may have to extract the backup, and just restore the configuration files, rather than everything. and even then there may be problems with different versions of applications, syntax changes etc.
I would suggest the much safer option would be to install ubuntu 18.04 on a different server/vps, and install everything on there as required by your needs and the perfect server tutorials, and then do a migration from your Debian 10 server to the ubuntu 18.04 server.

if you go ahead with an inplace downgrade/os switch, you should definitely back up all websites, all databases, all mailfolders.
and run a forced update of ipsconfig, and let that make a full backup of your ispconfig configuration as well.
I believe that will also create a backup of /etc, I would err on the side of paranoia, and separately backup all of /etc, /var, /usr, and /opt (if used) in case of differences.

 

Im pretty shure you cant change repo and downgrade in place.
It will fail hard.
Make a new box and migrate manually slowly or with other tools.

 

That is not a downgrade at all. Nor an upgrade. I do not know if there is a name for such an operation where an operating system is changed in place to another. Me too, I question the sensibility and workability of such an approach. ISPConfig Migration Toolkit works for migrating umpteen hundred customer accounts from old server to new, even when the operating systems are different and even when number of source servers differs from number of target servers.

 

Well, Ubuntu and Debian are quite similar. So it is possible to install the same software with (almost?) the same version and the same config.
Just install all the software and then use rsync to move the config/web/databases/mail .. . Adjust IP in configs and you are done.
In principle you should have a good backup solution in hand anyway. Good opportunity to try if it works ;-)

 

Hello All, Thanks for your responses - I do need to do this, (and I will) - because I nned to install something that only installs properly on ubuntu 18.04; and ISPConfig3 works well on both. I want to keep this particular server because it is a good price that has gone up in the 3 years I have had it, and I can't afford at present to rent another server - all valid reasons!

UNless I get some more specific advice - given that I have to do this and will do it - I'm just going to make all backups including ispconfig and db backups, and try a "downgrade" in-place by changing some of the apt repos (just the security ones first, I imagine to ubuntu and then running an apt upgrade, then doing it again after changing other repos - like main, then main partner non-free etc and do an apt upgrade after each one it apt allows - aptitude might give me more control over this I think) and then finally do an apt dist-upgrade - as if I were downgrading from ubuntu 19 to 18.

I always use buster and prefer debian, but in this case I need to use ubuntu 18.04 for a specific tomcat 9 apache project that simply doesn't work on buster - i've tried it. The specific media server repos are only available on ubuntu as are some of the libraries - and only 18.04.

Or do you think I should change all of the repos at once and do aptitude update, safe-upgrade, then a full-upgrade and finally a dist-upgrade?

Experienced advice is appreciated, and I will wait a day to get it - and regardless I'll post back with how it went.

Thanks again,

ed

 

this is from the Debian.org wiki:

it looks increasingly likely that what you're trying to do has a very good chance of breaking your server.
it sounds like you might need to do a clean re-install of the server.
I don't know how much data you've got on the server, if the data's on additional drives, they could be unmounted to keep the data safe, and to save time on reloading all the data.
I would still suggest running a migration from the Debian 10 to a ubuntu vps first though, to test everything works as expected. doesn't have to be a big vps. a t3.medium on aws in N. virginia would only cost $30 if left on for a full month, plus $1 for every 10GB of EBS disk.

you should be able to get the vps up and running, ispconfig installed, and configs migrated in a day, data transfer obviously depends on how much data you need to transfer to test with. then it's just a case of how extensively you want to test everything. shut the vm down when you're not actively testing it, and the only cost is the disk space.
if it all works, you might need to up the vm size to cover live cpu/ram usage, and then change all dns. reinstall and configure your server, and then change all the dns back. or now knowing it'll work, just start reinstalling the old server. depends on just how much downtime you can live with/are confortable with.