Oh, of course. I might not do it at all, in fact. But if I do, I always do dry runs.
I do have one client with several domains who’s going to need an upgrade soon due to traffic and storage, however; so I’m weighing options.
As a stopgap, I might replicate the Web sites on a new server and leave the DNS and mail on the existing one, to avoid having to clean up the messes I always inherit with IP addresses. I might also spin up a server or an AWS instance just to serve the images and videos. That would free up about 40 GB.
Ultimately I’ll probably move to Igor’s or Greg’s fork; but I may need to do something for this one client before they’re ready.
Done something similar a few times
Centos 7 / cPanel —> centos 8 / virtualmin
But I setup a new server and moved the accounts off one at a time (actually ran a backup per account over ftp to the new server)
CPanel adds a sub domain for every addon domain and this doesn’t always import the way you would like, but other than that haven’t had any issues importing cPanel backups. (Apart from sites that still run on old php versions as centos 8 only goes back to 7.2)
The existing server I’m thinking about has many subdomains of one domain, but no add-on domains. I haven’t had any problems migrating subdomains to Virtualmin, and don’t recall whether I’ve ever migrated any accounts with add-on domains.
I’ve also managed to buy some time by deleting a ton of mail. This company’s employees send me pictures and videos for which they are paid if I use them on the site. Some of them had several GB of these files in their Sent boxes, which was a massive waste of space. So I basically deleted anything in the Sent boxes that was addressed to me.
That buys me between six months and a year, by which time I hope that Lenix or Rocky Linux are up to speed. Prepping the accounts for migration from CentOS 7.9 to a RHEL 8 clone should hopefully be simpler than prepping for migration to Debian.
I also found a simple solution to the cPanel mail filters problem. The client does need those filters migrated. Everything needed to migrate them over to make them work with Procmail, however, is contained in the .yaml files that cPanel uses. So that problem is out of the way.
My issue was that I wasn’t interested in the sub domain, but this got copied over from cPanel anyway. Then the alias got parked on top of this sub domain in stead of on the main domain.
Probably wasn’t setup entirely correct on cPanel in the first place, but was working.
Easy enough to just delete and add again, as it was just an alias domain.
As for email, I always tell my clients: “it’s a webserver not an email server, it should work but if you want guarantees I can get you a gSuite or Office 365 / exchange email subscription”
I’ve been tempted to farm out the mail for about 20 years or so. I always wind up changing my mind in the end.
I have a few clients who pay me just to handle their mail (their sites are hosted elsewhere). They always say they weren’t happy with the other options they tried. So I guess I do it pretty well. What makes me different from the “other options,” I can’t rightly say. I make sure everything is properly configured and try to keep the spam down, but I’d think every provider does that. So I really don’t know.