Hi gresio64,
I have the same issue last time that centovacast cannot start the stream and it display the error "log file does not exist", normally centovacast cannot creat a log file if it cannot successfully run the stream so there must be something wrong with starting the stream.
SOLUTION:
login to your server as root via SSH and get the correct path of the stream configuration file and run it directly on the prompt like icecast -c /home/centovacast/vhost/[account]/etc/server.conf
check the output if it display and error and correct the error, maybe something wrong with the configuration file.
hope that help,
dards
Whooshstream.com