Oke, the rights in the disaster recovery must be wrong somewhere.
I managed to start te servers, don't ask me how. I logged in as the client, started the server, got notice that it started succesfully.
Then I had to go via SSH, see that the server was started under the admin account. Kill that sc_serv pid and after about a minute, the server restarted automatically under the centovacast user.
I had to do that for all clients seperately. This was not the case before the disaster recovery, then all worked fine except for that crontab kill error.
However especially in client sections:
1.) Logfiles can not be read ("Unable to access log file: Could not open log file" is the error notice)
This is an example of how logfiles are present in the vhosts/*/var/log directory.
-rw------- 1 centovacast centovacast 967 Dec 19 01:29 access.log
2.) Servers is displayed as being offline, while it's online
Pidfile is looking like this:
-rw------- 1 centovacast centovacast 4 Dec 19 03:30 server.pid
3.) Source connected NO (while it is in fact yes)
4.) Listeners: none (while in fact there are listeners)
So it must have to do something which changed in the wrong way when doing the disaster recovery which I did very exactly as shown.
I'm afraid we have to do a reinstall, but something must be wrong with that disaster recovery manual, otherwise my server wouldn't have gone down.
So I still would appreciate a fix.