On 01/08/2012 06:27 PM, Kent A. Reed wrote: > I had a few minutes this afternoon and decided to try another experiment with > this board---still running Ubuntu 10.04LTS with the 2.6.32-122-rtai kernel. > > I disabled Gnome (which shut down X) on the board by running the following > from the command line: > > sudo service gdm stop > > (I disabled a few other services too, like Apache, but I don't think this is > relevant. The stock Ubuntu/EMC2 install starts up far too many services for > my taste. When I want a controller, that's all I want, not a desktop > computer.) > > Then I logged out and disconnected keyboard/mouse/monitor (well, actually I > just set my KVM switch to another computer; possibly it still imposes some > electrical levels at the motherboard connectors.) > > Finally, I logged into the board via Ethernet from another computer using ssh > -Y and again ran the latency-test for 15 minutes with approximately the same > level of stress as before (2 copies of glxgear, web browsing, listing the > directories of an external USB drive, etc.). > > Bottom line: the latency numbers got even better. Max jitter fell to > 3211ns/3222ns. > > For some time I have envisioned running my tabletop mill with a headless > controller and a networked operator console. If anything, the present result > says this would be the preferred mode. Of course, I could make it cleaner by > stripping down the distribution some more, possible even install RTAI and > EMC2 over a Ubuntu server distribution to avoid the Gnome/X-server stuff > altogether, since there's the usual niff-naff about booting Ubuntu desktop > edition without a monitor attached, etc. > > I'm curious if anyone has tried this experiment with other boards and, if so, > what results were obtained. > > And, yes, I realize I am chasing after diminishing returns. The latency on a > stock board is already good enough for practical purposes. Let's just say my > home situation causes a form of ADHD were I work furiously on very short-term > projects. > > Regards, > Kent >
Kent, Just curious, while headless, which runlevel were you at? You're still going to have to run some form of X to get a remote display, and to do that you need to be at either runlevel 5 or kick off startx. You can run "init 3" to bring it down to a non-X runlevel, but you won't be able to run Axis remotely without X running on the headless system. Mark ------------------------------------------------------------------------------ Ridiculously easy VDI. With Citrix VDI-in-a-Box, you don't need a complex infrastructure or vast IT resources to deliver seamless, secure access to virtual desktops. With this all-in-one solution, easily deploy virtual desktops for less than the cost of PCs and save 60% on VDI infrastructure costs. Try it free! http://p.sf.net/sfu/Citrix-VDIinabox _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
