I don't know exactly how to troubleshoot the issue I'm having, so I'll ask here.
I have a USB 3G modem attached to a physical machine
server4 running ProxMox OS based on Debian Wheezy, and I can send SMS with it just fine using
echo "Message" | gsmsendsms -d /dev/ttyUSB0 -b 19200 <phone number>
This works well. Now I have a virtual machine (Ubuntu Server 14.04) installed on a different physical server
server1 also running Proxmox based on Debian Wheezy, and I want this virtual machine to access the USB modem on
So far I've tried using
server4 to 'share' the USB modem trough the network using this line in
2000:raw:0:/dev/ttyUSB0:19200 8DATABITS NONE 1STOPBIT banner
which should do the job from what I've managed to understand about
On the virtual machine I tried using
socat to add a virtual device linked to shared USB modem:
socat pty,link=/dev/virtualcom0,raw tcp:server4:2000
which seems to do the job, as the device
virtualcom0 appears in
/dev. However, if I try to send an SMS using
virtualcom0, I get a funny error:
user@vm:~$ echo "SMS Test Message!" | sudo gsmsendsms -d /dev/virtualcom0 -b 19200 <phone number> gsmsendsms[ERROR]: clearing DTR failed (errno: 22/Invalid argument)
I use the exact same command as on physical server where USB modem is connected, but it fails, and googling 'gsmsendsms errno 22' wasn't very productive.
In the end, I'd like to make a USB modem plugged into the physical
server4 accessible for Zabbix, which runs in a virtual machine on
server1. If there is a better way of doing this than using
socat, I'm ready to try something else.