serial fax modem, host linux, guest SBS 2011

[bleve97]

Hi,
Ongoing fiddly little bits with a move to a virtualised SBS2011 server. I have an old serial fax modem that the client wants to integrate (from their old SBS 2003 server).

I set up COM1 as a host port, /dev/ttyS0, set the permissions on ttyS0 to rw-rw-rw, took the defaults for IRQ etc in the Vm manager panel, plugged in the modem and started up the VM. PnP found the modem! Wow ... (it's an old US Robotics). The host OS is CentOS 6.2. There's two guests, but only one has the serial port mapped. The serial port is on the server hardware motherboard.

But then, the fax service refused to start and I'm not sure why. Attempts to connect to COM1 using a terminal emulator failed silently (using Putty). Any clues for how to poke around at this? I don't think anything on the host OS is trying to look at orlock the port, but am not sure how to tell anyway - it's been a _long_ time since I've done any serial comms work on a UNIX box.

[bleve97]

Turns out it was a permissions problem in Windows for a share it was trying to write to.
Serial comms works just fine!