How to migrate from Plesk to a new Ubuntu server
Copy each Plesk site over SSH while it keeps serving, move the mailboxes with their passwords, and change DNS only after you check the copy.
Check the fit first
KLYRN runs on Ubuntu 24.04 LTS, x86_64 only, with nginx as the web server. Plesk also runs on Windows with IIS, and on Debian and the RHEL family. A Windows site, or a fleet that must stay on AlmaLinux, does not fit here.
nginx does not read .htaccess. KLYRN reads those files during the move and turns the rules it understands into nginx configuration you review. It lists the rest.
Prepare the new server
Start from a clean Ubuntu 24.04 server with 1 GB of memory or more and 10 GB free. Ports 80, 443 and 7443 must be free. Install KLYRN as root:
curl -fsSL https://get.klyrn.com | sudo bashThe installer checks every requirement first and stops with a plain message if one fails. The install guide lists its eleven stages.
Connect to the Plesk server
In the panel, open Migrate and give it an SSH login to the old server. Root, or sudo without a password, lets KLYRN read the whole machine and propose the sites for you to map. A normal login moves one site at a time.
The connection check writes nothing on the old server. It names the step that failed, such as a name that does not resolve, a port nothing listens on, or a host key that changed.
Copy while the old site serves
The first pass copies each document root and its databases while visitors still reach Plesk. Database users keep their passwords, and a WordPress wp-config.php is pointed at the new database.
Open the copy on the new server and check it. Then run the final sync, which sends only what changed. That sync is the downtime, and the panel shows how long it took. For WordPress it can put the old site in maintenance mode for those seconds.
Mail is its own step
With mail hosting on, mailboxes come across from Plesk with their existing passwords. Autoresponders are named in the job log and not copied. KLYRN never changes your MX records, so point MX here only after you have checked the mailboxes.
Lower the TTL, then switch
Lower the TTL on each record a few hours ahead. The checklist warns above 300 seconds. Then point the records at the new server.
Keep the Plesk server for a week. Nothing on it was changed, so going back means pointing DNS at it again. Our guide to lowering TTL before a cutover has the timing.
What it costs
Moving over SSH works on the Free edition, which covers one server and five sites. Pro is $9 per server a month and limits nothing else. The Plesk alternative page compares the two, with sources.