Would like to try yunohost on my omv- and nextcloud-server (docker)! Will it overwrite sth important?

The message from yunohost on the screenshot worries me a little...

I am running nextcloud in a docker on an arm-device.

Can i install it without crashing nextcloud or loosing any data?

EDIT:

Just had a look in the docker-compose.yml of nextcloud:

The database- and the app-volumes (nextclouddb und nextcloudapp) are on my harddisk, so the only thing that could happen, is that mysql is not working anymore.