Hello, could you please clarify something? While reading the documentation on migrating from an old server to a new one, I have a question: does everything migrate, including domains, mailboxes, emails, folders, and so on, or only the containers and their settings?

The easiest way to create an exact clone on the new server is this: https://docs.mailcow.email/backup_restore/b_n_r-coldstandby/ I've done this myself a couple of weeks ago and it worked perfectly!

@"DocFraggle"#p20274 This is my first time doing this, so I made a backup just in case. Could you please tell me what values should be set in the create_cold_standby.sh file? Should I transfer the key from my old setup to the new one, or just create a new key? Also, should the host have an IP address, or is a hostname mandatory? Or is all of this configured in the rsync settings?

Step 1: SSH keypair in your old server. Check if you already have one in /root/.ssh/ (normally it's id_rsa.pub and id_rsa). If not, create one with `ssh-keygen` Step 2: copy the content of the public key (i.e. id_rsa.pub) and paste it in the file /root/.ssh/authorized_keys on the new server. (Create the file if it does not exist and make sure the permissions are set to 600) Step 3: edit these lines in the script on your old server and use the path to your SSH private file, i.e. ```plain export REMOTE_SSH_KEY=/root/.ssh/id_rsa export REMOTE_SSH_PORT=22 export REMOTE_SSH_HOST=your.new.server ``` (You can use your IP as well) Step 4: install rsync on both servers Step 5: check if ssh is working with public key auth from your old server to the new server `ssh your.new.server` Step 6: run the script :)

@"DocFraggle"#p20276 Thank you so much, it works. Thanks for the detailed explanation!

@"DocFraggle"#p20276 I have another question. I ran the script, and it gives me the following error: Creating remote mountpoint /var/lib/docker/volumes/mailcowdockerized_mysql-vol-1/_data for mailcowdockerized_mysql-vol-1... Creating consistent backup of MariaDB volume... [ERR] - Could not create MariaDB backup on source What could be the issue? I'm not sure how to understand and fix it.

Migrating a Mail Server from Old to New: Questions Arise

DocFraggle

Do you run the latest mailcow version?
Did you try to restart the stack?

docker compose down
docker compose up -d

DeadMouse_btw

DocFraggle
Yes, I’m using the latest version, 2024-11b.
I ran docker compose down and docker compose up -d, but the result is still the same.

DocFraggle

And you are running the script as root without sudo?

DeadMouse_btw

DocFraggle Yes, I have run it both with and without sudo, as I am working under the root user, but the result is the same whether I use root or not.

DocFraggle

Any specials about your mailcow setup? Any overrides?
I’m running this script on a daily basis and never had problems with it

EDIT: do you use multiple docker networks?

mailcow/mailcow-dockerized5799

DeadMouse_btw

DocFraggle I followed the documentation and didn’t come up with anything extra. I’m using a single Docker network (the output shows only one container).

DocFraggle

You could try to run the docker command manually (replace the variables with the appropriate values) to see where’s the problem

mailcow/mailcow-dockerizedblob/2024-11b/helper-scripts/_cold-standby.sh#L229

DeadMouse_btw

DocFraggle Thank you, I’ll give it a try.

DeadMouse_btw

DocFraggle Unfortunately, after replacing the variables, I got the same result. I don’t even know where to look for the error or what to do next.

DocFraggle

The docker command is trying to mount

${SCRIPT_DIR}/../_tmp_mariabackup

into the container to the /backup directory to create it’s backup there. Do you have any restrictions on creating directories/files?

So if you’re using /opt/mailcow-dockerized as the mailcow directory, it would create the _tmp_mariabackup in there

Next question, do you have selinux enabled or stuff like that?

DeadMouse_btw

DocFraggle No, it shouldn’t be necessary. I followed the manual and didn’t use any chmod commands to avoid mistakes. However, I might be unsure—if you could point me to where I should check, I’d appreciate it. The _tmp_mariabackup wasn’t created, but I’m using /opt/mailcow-dockerized. And yes, SELinux is enabled.

DocFraggle

DeadMouse_btw And yes, SELinux is enabled

That could be a problem, as in my opinion selinux is always the problem 😃
maybe try to disable it, reboot the server and try again

DeadMouse_btw

DocFraggle WORKS, THANK YOU!!!

DocFraggle

DocFraggle in my opinion selinux is always the problem

I rest my case 😅

DeadMouse_btw

DocFraggle
A couple of questions about cold standby. Does the script shut down the server automatically, or can it be configured so that the server continues to run after the script completes? Or is this handled via a cron job?

DocFraggle

The script just syncs everything. If you shut down the clone it won’t be started, if you start the clone it won’t be shut down

DeadMouse_btw

DocFraggle One more question, if you don’t mind answering, I would appreciate it. If I run the synchronization, will new emails be deleted or will they remain? Can I run this synchronization continuously and still keep new emails?

DocFraggle

I don’t understand, it’s a clone from the old system. So everything is wiped on the clone server before syncing

DeadMouse_btw

DocFraggle The reason I’m asking these questions is because it happened that my emails were copied, but only from one domain, and then the virtual machine shut down. I went to check on the new server, and the emails were there, so I thought everything was fine. However, it turned out that some emails were missing. That’s my issue :-)