Migration to new server using cold-standby script

rgomezc

Thanks @DocFraggle! I will try to make the switch later today.

rgomezc

So… I tried this and when calling sudo docker compose up -d I got the following output:

[+] Running 4/6
 ✔ Container mailcowdockerized-olefy-mailcow-1      Started                                                                                                1.0s 
 ⠋ Container mailcowdockerized-unbound-mailcow-1    Starting                                                                                               1.1s 
 ✔ Container mailcowdockerized-memcached-mailcow-1  Started                                                                                                1.1s 
 ✔ Container mailcowdockerized-dockerapi-mailcow-1  Started                                                                                                1.1s 
 ⠋ Container mailcowdockerized-sogo-mailcow-1       Starting                                                                                               1.1s 
 ✔ Container mailcowdockerized-netfilter-mailcow-1  Started                                                                                                0.9s 
Error response from daemon: error while creating mount source path '/opt/mailcow-dockerized/data/conf/unbound/unbound.conf': mkdir /opt/mailcow-dockerized: read-only file system

I am not sure what to check or change in this case… :/

Mhm, ok, apparently the new server has docker installed via snap, which for what I can find on the internet causes this problem. I remember installing it the same as the old VM but maybe I did not…

DocFraggle

Don’t use sudo, run everything as root use directly

rgomezc

Mhm, ok, apparently the new server has docker installed via snap, which for what I can find on the internet causes this problem. I remember installing it the same as the old VM but maybe I did not…

DocFraggle

Use the command from the docs to install docker

https://docs.mailcow.email/getstarted/install/

rgomezc

Well, Docker is/was installed like that. But apparently there was also the “snap” version, I don’t know why/how.

I am rebooting now after uninstalling the snap version and see if things are now normal, as now apparently the docker deamon is not running on the new server…

DocFraggle

rgomezc I suggest you run the script again after rebooting to set things right again

rgomezc

I can now start the mailcow instance on the new server, but I get this:

WARN[0000] volume "mailcowdockerized_sogo-web-vol-1" already exists but was not created by Docker Compose. Use `external: true` to use an existing volume 
WARN[0000] volume "mailcowdockerized_rspamd-vol-1" already exists but was not created by Docker Compose. Use `external: true` to use an existing volume 
WARN[0000] volume "mailcowdockerized_clamd-db-vol-1" already exists but was not created by Docker Compose. Use `external: true` to use an existing volume 
WARN[0000] volume "mailcowdockerized_crypt-vol-1" already exists but was not created by Docker Compose. Use `external: true` to use an existing volume 
WARN[0000] volume "mailcowdockerized_vmail-vol-1" already exists but was not created by Docker Compose. Use `external: true` to use an existing volume 
WARN[0000] volume "mailcowdockerized_redis-vol-1" already exists but was not created by Docker Compose. Use `external: true` to use an existing volume 
WARN[0000] volume "mailcowdockerized_mysql-vol-1" already exists but was not created by Docker Compose. Use `external: true` to use an existing volume 
WARN[0000] volume "mailcowdockerized_mysql-socket-vol-1" already exists but was not created by Docker Compose. Use `external: true` to use an existing volume 
WARN[0000] volume "mailcowdockerized_sogo-userdata-backup-vol-1" already exists but was not created by Docker Compose. Use `external: true` to use an existing volume 
WARN[0000] volume "mailcowdockerized_vmail-index-vol-1" already exists but was not created by Docker Compose. Use `external: true` to use an existing volume 
WARN[0000] volume "mailcowdockerized_postfix-vol-1" already exists but was not created by Docker Compose. Use `external: true` to use an existing volume

For what I can see in other posts and so on, it’s just a warning and I should be able to safely ignore it… but.. is there a way to “upgrade” or recreate those volumes to avoid this warning? I guess I could delete completely the backup from the new server and start from scratch, but I would like to avoid transferring 100Gb of data if I can 😛

Edit: I tried with docker compose down -vand it removed the containers… I’m running the create_cold_standby.shscript again and see if everything works fine afterwards.

Edit2: that did delete the volumes but also from disk (I am not really very experienced with docker… so this was my newbie thing I guess?) the create_cold_standby.sh is replicating the whole installation again apparently…

rgomezc

The switch has been done and everything seems to be working fine!

Thanks!!!

lumideez

rgomezc so how were you able to fix it. I’m trying to move my mailcow server to a server with bigger resources. how did you figure it out?

rgomezc

Hello lumideez - if I remember correctly, the original “error”, or the cause for the issues here was that I had installed docker with snap.

I uninstalled it and installed the correct docker version following the instructions on Mailcow, ran the create_cold_standby.sh script again, and that was it. It is as easy as that.

If you don’t have the snap-installed version of docker then you should not have any issues.