Hi, Up until now my main production server has been a "bare metal" installation of CentOS 7.9 hosting a variety of stuff. * DNS server with BIND for eight domains * IMAP mail server with Postfix and Dovecot for these domains, with about two dozen mail accounts * Webmail with Roundcube for all the mail accounts * Various WordPress-based websites and blogs * Several instances of the management software Dolibarr * The learning platform GEPI for our local school * One instance of OwnCloud for half a dozen users The hardware has no problems to deal with all that performance-wise. But managing all this in one big bulk has become a bit of a problem, since the LAMP-based PHP applications (WordPress, Dolibarr, GEPI, OwnCloud) increasingly cultivate their idiosyncrasies, so this feels more and more like herding cats. My main goal in migrating all this stuff preogressively to a series of neat VMs hosted on a KVM hypervisor is clarity and ease of maintenance. Now I wonder what could be a smart subdivision of all these VMs. After a bit of brainstorming, here's what I can come up with. 1. It would make sense to regroup all the applications, e. g. one VM for all the Dolibarr hostings, and then a different VM for WordPress, and a third VM for OwnCloud. 2. It's tempting to have a lot of small VMs for clarity's sake. On the other hand, it's maybe better to have one single VM for all the mail stuff. 3. Should I put all the Roundcube instances in a separate VM? Or does that go with the Postfix/Dovecot mail VM? 4. DNS is a bit of a special case, a bit of a catch 22. I would be tempted to setup an extra (bare-metal) machine for just handling this. Since BIND provides the DNS information about the hypervisor and the backup server themselves this becomes a bit of a chicken-and-egg situation. 5. Even if it's tempting to multiply VMs, let's not forget that I have to keep an eye on hardware resources, not to forget I have to pay for every extra IPv4 address. I'd be curious to have your input, since I'm fairly new to this sort of approach. Cheers, Niki -- Microlinux - Solutions informatiques durables 7, place de l'église - 30730 Montpezat Site : https://www.microlinux.fr Blog : https://blog.microlinux.fr Mail : info at microlinux.fr Tél. : 04 66 63 10 32 Mob. : 06 51 80 12 12