Replace old Seafile server in Docker

Guys, I have to make the impossible possible.
I don’t have much Linux knowledge and the colleague who was actually responsible is gone.

We have a relatively old Seafile server that no longer boots up properly when you restart it. Seafile is installed there without Docker.

The plan was to set up a new Seafile server with Docker and import the data from the old server into the new one. (Good 3 TB)

Fortunately, the new Seafile server is already up and running, now the next step is the migration, which I have to take over.

Old server:
Debian 11
nginx/1.18.0
Seafile 10.0.9 (probably)

New server:
Ubuntu 22.04.4 LTS
Seafile latest

I have nothing but coffee, ChatGPT, Linux basics and the post “Migrate from non-docker Seafile deployment to docker”

This is how I would proceed:
Docker Seafile to 10.0.9 so that the version is the same.
(Remember, I can’t reboot the old one, it probably won’t start.)

Kill all the services:
systemctl stop nginx && systemctl disable nginx
systemctl stop memcached && systemctl disable memcached
./seafile.sh stop && ./seahub.sh stop

Copy the DB to the new server from
/opt/seafile/conf and /opt/seafile/seahub-data
(probably chmod 777 once because otherwise it won’t work?

to /opt/seafile-data/seafile on the new server.

Then boot up the server
cd /opt/seafile-data
docker compose up -d

Then there are these strange security precautions:
iptables -A INPUT -s 172.16.0.0/12 -j ACCEPT #Allow Dockernetworks
iptables -A INPUT -p tcp -m tcp --dport 3306 -j DROP #Deny Internet
ip6tables -A INPUT -p tcp -m tcp --dport 3306 -j DROP #Deny Internet

Thats it… I guess?
Does that work so far, are there any objections?
Many thanks for any feedback!

Have you checked this guide below? I believed it can cater your migration need:
https://manual.seafile.com/maintain/backup_recovery/