hello all, and many thx yunohost you stay awesome.
after struggling with migration postgres, i found the solution (for me) on good old stackoverflow.
Verify the current cluster is the still the old version:
$ pg_lsclusters
Ver Cluster Port Status Owner Data directory Log file
11 main 5432 online postgres /var/lib/postgresql/11/main /var/log/postgresql/postgresql-11-main.log
13 main 5434 down postgres /var/lib/postgresql/13/main /var/log/postgresql/postgresql-13-main.log
Run pg_dropcluster 13 main as user postgres:
$ sudo -u postgres pg_dropcluster 13 main
Warning: systemd was not informed about the removed cluster yet.
Operations like "service postgresql start" might fail. To fix, run:
sudo systemctl daemon-reload
Run the pg_upgradecluster command as user postgres:
$ sudo -u postgres pg_upgradecluster 11 main
Verify that everything works, and that the only online cluster is now 13:
$ pg_lsclusters
Ver Cluster Port Status Owner Data directory Log file
11 main 5434 down postgres /var/lib/postgresql/11/main /var/log/postgresql/postgresql-11-main.log
13 main 5432 online postgres /var/lib/postgresql/13/main /var/log/postgresql/postgresql-13-main.log
**Drop the old cluster: //ONLY IN CASE NO ERRORS APPEAR**
$ sudo -u postgres pg_dropcluster 11 main
Uninstall the previous version of PostgreSQL:
$ sudo apt remove 'postgresql*11'
after that i restarted nginx (dont know it necessary)
and have to restart postgres cluster twice to get mobilizon workable (got an heart attack mobilizon was empty after first restart) with
sudo pg_ctlcluster 13 main restart
thats it 