OpenVPN clients work fine when they're started by /etc/init.d/openvpn for the first time, but they can't reconnect if the master server is restarted.
This is the error I get in syslog:
ovpn-openvpn: Note: Cannot ioctl TUNSETIFF tun: Operation not permitted (errno=1) ovpn-openvpn: Note: Attempting fallback to kernel 2.2 TUN/TAP interface ovpn-openvpn: Cannot allocate TUN/TAP dev dynamically ovpn-openvpn: Exiting
This are the file permissions of tun device:
crw-rw-rw- 1 root root 10, 200 2011-03-24 16:51 /dev/net/tun
If I then restart the client using "/etc/init.d/openvpn restart", they connect normally.
Also, problems only appear when openvpn runs as user 'nobody'. Running as 'root' solves everything but it's not a viable solution.
'persist-tun' option also helps a bit, but not too much. Tunnels still don't last overnight.