Remote desktops on Linux

I was looking for ways to distribute a whole desktop over the LAN at work onto my current desktop. I thought I’d mention them here so other people are aware of them.

Xnest
Using Xnest provides you with the remote desktop within a window, much like VNC does. This is also more secure than the other method of doing it, and if you have the bandwidth can work over the internet fine, it requires you to have Xnest installed on the machine you wish to forward the desktop from (ben) . From your main desktop (bill) you ssh to ben with X forwarding on.

ssh -X ben

Now your on ben, you need to run (adjust the resolution to fit you needs)

Xnest :1 -geometry 1280x810 -query localhost

gdmflexiserver and XDMCP
This isn’t as secure as the previous method as all of the key presses/mouse movements/graphic content is transmitted over the network in plain text. As it communicates via UDP your unable to tunnel it over SSH currently. However this method blends in better with my current desktop.

First of all you need to enable XDMCP on ben. Instructions for Edgy/Feisty Ubuntu can be found here

Once that is configured and working we need to start gdmflexiserver. This allows you to run seperate GDM sessions on demand in a new virtual console. You launch it via a terminal with

gdmflexiserver

This provides us with a new session on console 9 (Alt+Ctrl+F9) along with our current one on console 7.

You then select ‘Remote Login via XDMCP’ from the options, enter the address of ben and press the connect button. You should now have login screen for ben, once you’ve logged in you’ll have bill’s desktop on console 7 and ben’s desktop on console 9.

Virtual Machines
I’ve not played with this but in theory, if you main hosts is running virtual machines with GUI’s you can use this method to map them all to virtual consoles. This should be fairly safe as networking traffic shouldn’t leave the actual PC and go onto the network but this will require checking.

Shameless plug

I help run a free bannerless multi-player empire building strategy web based game called “Holy War”. We tried to distinct ourselves from all the other games out there with 3 “key” features:

1) Team orientated:The game is designed to encourage team playing, with small sovereignty’s which you can play with your friends or on your own. The religion side of the game is where you fight as part of an ‘alliance’ of players devoted to your religion where your aim is to help your religion win.

2) Religion System:There are 5 different religions and each religion is run by a High Priest (The players themselves select the new High Priests at the end of each era). These High Priest interact with the “real” world with spell-casting etc. At the High Priest level those 5 players/religions fight against each other. Together they have access to a large selection of spells and constructions which give bonuses to themselves or their followers.

3) Extensive Options for “regular” players: Each player can choose between 3 different alignments and together with the 5 religions, which leads each player to have access to a variety of upgrade combinations. There is also a tech tree with over 50 technologies that can be researched and over 25 buildings that can be constructed.

The next round is due to start Thursday 10th midnight BST, so throw your armies into the fight by joining here

MythTV – My Setup

I’ve had a few people asking me about my setup of mythTV so here it is in a more persistent form, and better explained.

What is mythTV

I’m going to assume you already know about MythTV if not check out its site here and the wiki entry here

I’m currently running my setup with a dedicated back-ends and 2 front-ends which I’ll describe below.

Back-end

Hardware is as follows:

• Pentium III 450Mhz
• 384MB SDRAM
• 2 Hauppauge Nova-T DVB cards [1]
• 250GB SATA disk on a pci controller
• 40GB IDE disk

I’m not sure what the minimum specs are for mythtv, but alot of people are surprised I’m able to run it smoothly on a low powered machine like this. Commercial flagging takes its toll on this rig though, so you best leave it off you record quite a few shows. My average load watching liveTV + a recordings is around 20%. This machine is running Ubuntu Dapper and is due for an upgrade to accept more tuner cards (need more PCI slots, as the SATA, NIC and GFX use up the other 3.

Front-ends

I have 2 front-ends, the 1st is a dedidicated EPIA 1500EN mini-itx board[2] with 512MB DDR2 running Ubuntu Feisty. This has a custom compiled graphics driver to allow for TV-OUT over S-Video (since the version I needed wasn’t in the repo when I built it). Making use of the hardware MPEG2 decoding enables very smooth playback without much cpu usage. I also have digital sound output working is great. The connection for this is via a scart cable after passing through my cinema amp. This machine makes use of an ATI Remote Wonder II for its remote control.

My other front-end is my desktop PC, this is a AMD 3000XP+ Athlon with 1GB DDR running Ubuntu Feisty. This generally plays back fine, how-ever the cpu load is quite high, around 80% which can sometimes produce a few frames to freeze/skip.

Out of the 2 front-ends I have, I’d recommend getting the mini-itx board (not sure what the cheaper boards are like as I can’t afford them to test) as it has these advantages

• Quieter to run, you can even get a fan less version.
• Cheaper to run, since they need a lot less watts (<30 I believe at full load) which will soon added up if its left on 24/7
• Has digital sound/5.1 surround/TV-OUT on board, no extra components to buy
• Small foot print, so fits in well under your TV. Mine is in a case around the size of a 1U DVD player.

Whilst setting up my mythTV I used guidelines from this site, which is quite helpful here.

[1] Hauppauge Nova-T DVB card

[2] VIA EPIA EN Mini-ITX mainboard