[AG-TECH] Room node on single machine with LXC

[Christoph Willing]

For a long time now, machines have been powerful enough to run all AG  
services, including capturing multiple video streams, on a single  
machine. For a desktop node with just a single camera, this is great.

The disadvantage of a single machine with multiple cameras is that  
each video capture uses a separate vic instance. This means that, as  
well as anything else you may want to run on the console display, you  
additionally have a bunch of vic instances - each of which has a  
thumbnails for all streams from external sites as well as for the  
stream its capturing. This can be quite confusing - especially for  
"ordinary users" that you may be letting run their own meetings after  
doing an initial setup for them.

The advantage of 2 separate machines is that the VideoProducerServices  
are tucked away, out of sight, on the capture machine, leaving the  
display machine with just a single vic instance (from a  
VideoConsumerService).

A few years ago we used Xen to run the VideoProducerServices in a  
virtual capture machine on the same physical hardware as the display  
machine. It was a bit messy to set up and needed kernel patches, so  
ultimately not easy to maintain and we never persevered with it.

There's now a new virtualisation technology, with all the necessary  
bits already in the kernel (since 2.6.29), called Linux Containers  
(LXC). I've used this to make a prototype room node (separate display  
and capture machine with multiple cameras) on a single physical  
machine. Its still a bit messy to set up initially but well worth the  
effort. Construction details are at:
	http://www.vislab.uq.edu.au/research/accessgrid/software/lxcag/


chris


Christoph Willing                       +61 7 3365 8316
QCIF Access Grid Manager
University of Queensland