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This is what I want!

New MessageThis is what I want! (modified 1 times) erroneus
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I want either an X-terminal type setup for this hardware or something that runs primarily off of a network file system. It can be taken for granted that everyone here has at least one other computer that can be used to serve to the iPaq.

Simply running Linux and X off of the iPaq puts two obvious blocks in our path -- RAM limitations, local storage limitations. RAM limitations do not appear to be addressable which really cuts into what this machine can do for the user. Local storage limitations are being addressed creatively, but most of these solutions (external USB drives, CF->IDE devices) are QUITE expensive and moves most people beyond their original intent which is to get this $99 device to serve a useful purpose. When the device becomes a conglomeration of devices amounting to a $500 investment or more, it's clear we're beginning to lose sight of the original scope or intent of what we wanted to hack out of this thing.

It's obvious that we can't escape the need for a USB ethernet adapter. Compaq was too cheap to supply one or they believed too many people would put their phone line into it... hehehe either way, it's not there though there is space for it on the system board. But outside of the ethernet device (which should not cost anyone more than $50 and I've seen mentioned for as little as $10) this is all that we should need to make something useful with this.

So, I have heard mention about setting it up as an X terminal. Has anyone done this? How do I make it go? Does anyone have any HOWTOs documenting this? I think the X terminal plan rocks because all local storage is actually local though the display isn't. We don't have to worry about issues such as the life of the CF memory either onboard or offboard the system board. Additionally, since programs are actually running on the server, we needn't concern ourselves with the 32MB (30MB actually) RAM limitation.

The other option is a good working setup for a network file system (SMB or NFS). That would also be very cool but it doesn't address the RAM restriction very well.

I love what Rasmus is doing -- he's my hero. I hope he can expand his project to suit one of the tasks mentioned above. :) It would be quite ideal.

But attempting to create a stand-alone appliance... VERY challenging and perhaps that's why many are aiming at this goal. A suitable web browser would be very challenging to run within these limitations. But the probable results of this effort couldn't possibly result in anything with appreciable performance as far as I can tell. I believe better performance will come from either the X terminal or Network File System workstation client.

12-28-2001 10:34:11

New MessageRE:This is what I want! (modified 0 times) bittmann
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XTerminal Discussion.

Yes, it's possible. It can even be easy...but there is a price.

If you're on a network with another linux box (let's say it's called <otherhost>, with ip address of <otherip>), invoking X like "X -query <otherhost>" or "X -query <otherip>" *might* do the trick for you. (*Note -- using hostnames only works if you have a proper nameserver on your network, or if you have added the hosts to /etc/hosts. Otherwise, use IP addresses!).

I say *might*, because performance (at least with a USB nic), is pretty marginal. Gnome and KDE just write too much data to the screen...fvwm is a little more agile, but still lags a good deal. However, it's good enough to do basic Mozilla browsing and email...just be ready to wait when big chunks of the screen change.

You do have to set up XDM on <otherhost>, and allow connections from the iPaq.

As this is *very* insecure, I do suggest that you only do this if firewalled (either by a dedicated router, or within the linux box, e.g. set up with two network devices. If you place your iPaq on an exposed segment, at the very least give it a non-routable address (such as 192.168.x.x) and set up the interface and routes on your linux box appropriately!

On the "plus" side, this desktop looks *just like* the desktop of the user in question on otherhost ('cause it is!)

On the "minus" side, because everything is being served from <otherhost>, there is a *lot* of network traffic, which is pretty slow.

Check out http://www.linux.org/docs/ldp/howto/XDMCP-HOWTO/index.html for a quick synopsis of what's required for setting up XDM.

A faster solution (that's not quite as convenient, but *much* more responsive) is to use the local machine's window manager (currently Blackbox), while redirecting DISPLAY from <otherhost>.

From the iPaq:
startx
launch rxvt
"xhost + <otherhost>" or "xhost + <otherip>" (allows <otherhost> to display on our screen)
"telnet <otherhost>" or "telnet <otherip>" (or ssh, or walk over to the other machine and log on!)
"export DISPLAY=<iPaq ip address>:0"
"xclock" (or "mozilla", or whatever)

If this works for you, you could set up <otherhost> for remote calls, and remotely launch applications without having to go through the telnet/ssh/whatever route.

The same problems with security remain. This is *very* insecure in a non-firewalled environment. You Have Been Warned!

bittmann

12-28-2001 11:08:04

New MessageRE:This is what I want! (modified 0 times) bittmann
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Network File System discussion.

Very viable, but with a couple of tradeoffs. I've been successful in using NFS to help transport files/make backups/etc., and while it does work, it is rather slow (thanks to the limitations of a USB nic). It's also only viable in a firewalled environment...

Good place to start: http://www.linux.org/docs/ldp/howto/NFS-HOWTO/index.html

Good candidates for mount points: /home, /usr/local, /opt (in some situations), /tmp, and /var.

Stupid trick: Make a swapfile on a NFS-mounted partition. Yes, it's slower than heck...but it *will* keep you from crashing with "out of memory" errors.

something like:

mount <otherhost>:/tmp /mnt/a (or mount <otherip>:/tmp /mnt/a ???)
dd if=/dev/zero of=/mnt/a/swapfile bs=1024 count=65536
mkswap /mnt/a/swapfile
swapon /mnt/a/swapfile

I know I've already said this, but it bears repeating: DON'T run naked NFS services in a non-firewalled environment! At the very least, make sure you're segmented before enabling such services. You Have Been Warned!

bittmann

12-28-2001 11:31:36

New MessageRE:This is what I want! (modified 0 times) rman
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Remote X works pretty well in my opinion. I will leave the detailed security discussion to others with that expertise but it does not seem to me that it is a gaping security hole. I use the telnet option and you have no less than three security checks in place between the servers host.allow and telnet login then the remote machine needs xhost set to allow the servers to access it's subsystem. I can see where just the existence of telnet is a problem but if setup correctly it seems that it should be relatively secure. I run a remote K desktop on the iPaq and use Konquerer as the web browser. This is alot friendlier for my family and honestly does not seem to perform very poorly at all. I only have a 10 Meg network as well so I would have to say it suits me just fine. Good luck with your setup.
12-28-2001 12:14:07

New MessageRE:This is what I want! (modified 0 times) Root
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Easyest way to lauch applications off a server is to run blackbox as usual, then open rxvt and ssh to the server, login, and anything you run is automaticaly exported to the ipaq display© example:

„in rxbt€
ssh mylinuxserver -l myusername
password: xxxxxx
bash$ emacs

will open an emacs on the ia1©

12-28-2001 13:01:43

New MessageRE:This is what I want! (modified 0 times) Root
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The direction is right, but there are a few things to consider:

1€ depends on another server being up© personally i prefer a stand alone appliance©
2€ if you have a few ia-1's, it requires a strong server©
3€ very slow response©

12-28-2001 13:08:13

New MessageRE:This is what I want! (modified 0 times) bittmann
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"Root" is right...the ssh option *is* the easiest, as well as (IMHO) the safest...however, there is an additional penalty in the CPU requirements of encrypting/decrypting the data stream. Works *very* well for low-bandwidth applications...but can become an additional performance factor (assuming your network connection can outpace your encryption routines). This *may* not be a very big issue with a USB nic (and will most likely not be an issue at all on a 10-base network).

Another thought...I wonder if one uses the "compression" option in ssh to compress the datastream, if the penalty of the compression/decompression would be offset by the additional throughput from sending fewer bits over the wire? It's definitely a performance loss over a ISA/PCI nic (let alone a bus-mastering one!), but a USB device *might* get some benefit (assuming, of course, that the data lends itself to compression). Additional: What if one limited the ssh encryption to (say) 56 (or even 40) bits by twiddling the cipher?

So, "Root", how do you feel about running x11perf using various methods and posting your results? I'd expect that direct export would be fastest, ssh next, and "compressed" ssh slowest on a high-bandwidth network...but there could be a surprise in there...

bittmann

12-28-2001 13:27:42

New MessageRE:This is what I want! (modified 0 times) AirMan
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I'm a fan of XDM. I log into the IA-1 and enter "X -query m10 -bpp 16". Then I log into the XDM host, which is running the window manager, etc. Works perfectly. This all happens behind the firewall, mind you. By the way, I also point the IA-1 at a remote font server. This also works perfectly.
12-28-2001 13:55:31

New MessageRE:This is what I want! (modified 0 times) Chase
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The most recent issue of Linux Journal http://www.linuxjournal.com/ has a writeup of using VNC with X to provide persistant desktops. Combine that with TightVNC and you might have something.
12-28-2001 15:53:52

New MessageRE:This is what I want! (modified 0 times) bballctaulbee
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a good candidate for your IA-1 Linux image:

netcat! the nc command could replace quite a few other commands... not only does this command do everything-network-but-the-kitchen-sink, but i believe its footprint is quite small...

12-28-2001 20:26:18

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