I have your ubiquitous computer right here.

by Kyle Rankin

Related link: http://www.post-gazette.com/pg/04187/341822.stm

You always hear people talking about "ubiquitous computing"--the idea that at some point computers will become so pervasive that you will just hop from one computer to the next throughout your daily life.

According to this article on post-gazette.com, researchers in Pittsburgh are developing an application to manage virtual machines capable of suspending an application on one computer, moving to another computer, and having all of the applications and files resume locally on the new computer.

In many ways it's somewhat like the screen command, or something like the work done by the AT&T Labs in Cambridge except in those cases the application stays running on a server somewhere and you just connect and input and output moves across the network. In this case it seems files are actually transferred locally to whatever machine you are connected to.

It's an interesting concept, and I look forward to seeing where their research leads. In the meantime, though, you can do a lot of the same things just with a Knoppix CD and a usb key drive.

Here's how:

One of the big things that has made Knoppix so popular is just how well its automatic hardware configuration scripts work. You can take a Knoppix CD to basically any computer, boot it, and most if not all of the hardware is working by the time the desktop environment comes up.

Knoppix has packed in all sorts of useful tools from a complete office environment, web browsers, instant messengers, email clients, games, the list goes on, so that many people have started using Knoppix CDs so that they could use their favorite Linux tools when they weren't in front of their main Linux machine. Knoppix is really good about not doing anything potentially dangerous to the underlying system until it is explicitly told, so you could boot up Knoppix on your friend's computer, or even a computer at Best Buy, and shut it down without leaving any tracks or damage.

Knoppix has the ability to use a writable device like a usb key drive, as a persistent home directory. This means all of your files and settings stay on the usb drive, so you can carry it around with you, boot on any machine you are in front of, and pick up where you left off.

A persistent home directory is pretty simple to set up. Basically you need some kind of writable media you can carry around with you. Usb drives, floppy drives, or even your iPod qualifies. Boot into Knoppix with the device plugged in, and make sure you can access it, then click Kmenu->KNOPPIX->Create a persistent KNOPPIX home directory (or run /usr/sbin/mkpersistenthome from a console).

When the wizard launches, pick the drive to use, and tell Knoppix to create a loopback file on the device (basically a complete filesystem written to a single file, like CD Images). You can choose how much space you will allow for this home directory, so you don't have to worry about filling up your USB drive or iPod if you don't want to. The wizard will create the loopback file and copy your complete home directory to the loopback file, and then you are done.

Next time you boot, if you add the cheat code home=scan to the boot prompt, Knoppix will scan all drives on the system (including your usb key drive, iPod, etc) for the loopback file. All of your settings and files on your desktop are where you left them, and you can get right back to work. Any changes you make in your home directory are written to this loopback file, so changes stay persistent across reboots.

There are a lot of different persistent options in Knoppix, so many I can't really fit them here, but if you want to get a head start on this whole "ubiquitous computing" thing, I recommend grabbing a usb key and giving Knoppix a look.


2004-07-09 21:33:42
ssh, X, VNC, RDF, etc.
I have used a simular solution for years except that keep all of the data on my home network and then connect back using ssh and X. This allows me to use my home environment and recources anywhere that I have a network connection. I carry a live Linux CD (I use Slax or LNX-BBS because they fit on a 3" CD) and a floppy with an authorized public key to my firewall/gateway computer. Then all that I have to do is ssh back to my own computer. If I want to run X programs and the available network bandwidth supports it, then I can tunnel X applications to the local display as well.

I also carry a Windows ssh client (PuTTY) in case the local policies prevent me from booting my own CD. I have not found a good X server for windows so that means I am stuck at the command line which is fine for me. If someone really requires graphical connections for Windows then I would imagine that running a VNC server and carring a client of the floppy could solve that problem.

2004-07-09 23:37:27
knoppix and ... everything?
I seem to hear about Knoppix every month or two. What I'm finding is that certain user/developer groups grab their favourite application and create a little knoppix distro with their custom app on it. This is the case with a bunch of open source mapping/GIS tools. If anyone is interested in the link to a knoppix ISO with GRASS GIS, MapServer and QGIS desktop installed, I'll hunt it down for you.

It's great to see that folks are spending time packaging up apps for Knoppix. I guess they've got good "Create your own / add your own app" documents.

Tyler Mitchell

2004-07-12 13:55:35
knoppix and ... everything?
Once you get the hang of it, modifying Knoppix with your own packages really isn't too difficult. Honestly the most challenging thing about it is keeping the file size down.

Maybe I'll write an entry about it some time here in the future.

2004-07-13 09:10:37
ssh, X, VNC, RDF, etc.
The x11 distribution that now comes with cygwin seems to be pretty good.