Hi,
Recently I have installed virtualmin on ubuntu 16.04, everything works fine except that the virtualmin url https://ip:10000 sometime give Unable to connect error, even though all webmin processes seems are running normally. Nevertheless, after service webmin restart, it is accessible again.
Below is the output of a few command lines when it is unable to connect
root@server:~# service webmin status
● webmin.service - LSB: Start or stop the Webmin server
Loaded: loaded (/etc/init.d/webmin; bad; vendor preset: enabled)
Active: active (running) since Tue 2017-12-05 04:07:56 EST; 1 day 5h ago
Docs: man:systemd-sysv-generator(8)
Process: 32519 ExecStop=/etc/init.d/webmin stop (code=exited, status=0/SUCCESS)
Process: 32531 ExecStart=/etc/init.d/webmin start (code=exited, status=0/SUCCESS)
CGroup: /system.slice/webmin.service
├─ 6864 /usr/sbin/dovecot
├─ 6865 dovecot/anvil
├─ 6866 dovecot/log
├─15958 /usr/share/webmin/virtual-server/lookup-domain-daemon.p
└─22180 /usr/bin/perl /usr/share/webmin/miniserv.pl /etc/webmin/miniserv.conf
root@server:~# ps aux | grep miniserv
root 2020 0.0 0.1 11228 880 pts/0 S+ 09:53 0:00 grep --color=auto miniserv
root 13046 0.0 0.2 76292 1356 ? Ss Dec05 0:00 /usr/bin/perl /usr/share/usermin/miniserv.pl /etc/usermin/miniserv.conf
root 22180 0.0 6.6 141176 34992 ? S Sep06 0:00 /usr/bin/perl /usr/share/webmin/miniserv.pl /etc/webmin/miniserv.conf
Then, I restart webmin service webmin restart and I can access virtualmin url.
This happens occassionally (once every 1-2 weeks)