NX notes

(This is about the X11 compression protocol, not the feature of newer
x86 CPU's that give better memory protection)

http://www.fedoranews.com/contributors/rick_stout/freenx/

Apparently there is an opensource version of the server at the above
URL, but then you're expected to download a client from nomachine.com.
They had clients for a variety of linuxes, mac, solaris and windows.

rpm'ing the client provided /usr/NX/bin with a variety of executables,
including "nxclient".

Running nxclient brought up a GUI-based configuration dialog.  I chose
to select a VNC connection from among the choices, but upon trying
to connect, I got an error about NX not being present on the server,
despite having just rpm'd two NX server-related rpm's.

I had NX (ssh) authentication problems initially, because although
the public and private keys on the client and server started out with
the same initial characters, they were -not- the same!  So I used
ssh-keygen -y and entered the path to my dsa private key on my client
host (at home), which gave me the correct public key, and put that
into ~nx/.ssh/authorized_keys2.  Then I could ssh nx@seki.nac.uci.edu
(from the client - home, to the server - seki), without a password.

Next, even though I asked the NX client to connect to my VNC session
on seki, I had to enter my unix password on seki, not my vnc password,
into the NX client at home.

Next hurdle: sometimes when I connect via NX, I got "error in options
string: 'NX> '.", and once I got a "big !M" screen.  I see a lot of
people saying that "error in options string" thing is due to a space in
the session name, however, I don't have any spaces in my session name.
I also tried renaming my session from "seki.nac.uci.edu" to just "seki",
but that didn't help either.

I've traced down a network problem on my DSL router:
root@OpenWrt:/proc/sys/net/ipv4/conf# for i in */proxy_arp; do echo 1 >
$i; done
This is definitely helping my VNC sessions...  As far as NX goes, this
was necessary, but not sufficient...


nxtunnel didn't work that well for me:
http://web.walfield.org/pub/people/neal/nxtunnel/
It required:
http://ftp.debian.org/debian/pool/main/n/netpipes/netpipes_4.2.orig.tar.gz
...and ISTR that it wanted NX in your home directory, not in the place
the RPM's put it


To get two nxproxy's talking:
1) On the remote machine, run: nxproxy -C
2) If the above says it's on 4008, then run the following on the local
   machine: nxproxy -S seki.nac.uci.edu:8
..be sure to unblock tcp 4008 or whatever in your firewall, if any.


I scrapped the nxproxy's, and got results almost immediately.  I finally
went back to nxclient, toasted the VNC config inside it, and went to a
custom X command: vncviewer.  And it usually works very well now.  :)


It really is very fast.  At first, I wasn't that impressed, as it
seemed to take a while to redraw some things, but then I cranked up the
cache sizes, and it's quite impressive.  Starting up a session can be
flakey still - sometimes I got that same silly error about "NX> ",
and other times vncviewer freezes very early on (before the first full
screen draw finishes), but it's setting up sessions well, often enough,
that I'm using NX a lot now.

2005-04-08

I concurrently conducted 4 large downloads today, and NX's performance
was still quite liveable.  In fact, even xpenguins was still reasonably
smooth.  :)

2005-04-18

It was suggested on the LTSP mailing list that NX uses ssh compression,
in addition to its own.  True?

On ubuntu, it is suggested to do:

 It's not in Ubuntu's repositories, but is available for Debian. Add
 the following line to your /etc/apt/sources.list

deb http://kanotix.com/files/debian/
./

The repository is for Kanotix, a Debian/SID Knoppix derivative.

Run apt-get install freenx.

Then, run nxsetup

...however, the apt-get command yields:

root@ubuntu:~# apt-get install freenx
Reading package lists... Done
Building dependency tree... Done
W: Couldn't stat source package list http://kanotix.com ./ Packages
(/var/lib/apt/lists/kanotix.com_files_debian_._Packages) - stat (2 No
such file or directory)
W: You may want to run apt-get update to correct these problems
E: Couldn't find package freenx
root@ubuntu:~#

So next I'm trying:

http://www.gnomeuser.org/documents/howto/nx.html

Alas, this stuff appears to be True Blue NX, from NoMachine, not a
version of FreeNX.
BTW, the doc that comes with it has a section on how to set it up with LTSP...

NoMachine's GPL'd portions:

Instructions for building and running:
http://web01.nomachine.com/documentation/building-components.php

Oodles of GPL source code, unfortunately often as forked copies of very
established projects:
http://www.nomachine.com/sources.php

Includes a link to a mandrake src rpm:
http://www.linux-tip.net/cms/content/view/158/6/

Rumor has it that playing a movie via NX is slower than raw X11.
The poster indicated that with NX, the CPU would get pounded, and you
could only play in a small video window.

http://www.linuxjournal.com/article/8342