Difference between pages "Nx" and "Build and install gphoto2"

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(Difference between pages)
imported>ThorstenStaerk
 
imported>ThorstenStaerk
 
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NX allows you to set up a terminal server. You will be working in front of a computer (the ''client'') that is connected via [[netWork]] to another computer (the ''server'') that does the actual work. Your client will only forward the server's display. NX is faster than [[vNc]].
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gphoto2 is a utility to download pictures from a [[digital camera]].
  
= Install NX as display manager =
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To [[build]] and [[install]] it, [[find out your distribution]] and proceed accordingly
  
Maybe you have a very old computer and want to make it a [http://en.wikipedia.org/wiki/Thin_client thin client] to a faster one (the faster one acting as [[terminal server]]). Then you want the old computer to display the NX client program right after startup, without a user having to log in. So you want [[Nx]] to be your display manager. Here are some changes I did to /etc/init.d/xdm to make this happen:
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= SUSE Linux 12.1 =
 
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* [[open a console]] as root and [[install]] some [[dependencies]]:
case "$1" in
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[[yast]] -i libgphoto2-devel
    start)
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* download the source code from http://sourceforge.net/projects/gphoto/files/gphoto/
        X &
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* [[extract]] it, in this example version 2.4.14:
        export DISPLAY=:0
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  cd
        /usr/NX/bin/nxclient
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  [[tar]] xvzf Downloads/gphoto2-2.4.14.tar.gz
        [[scripting tutorial|while]] true; do [[sleep]] 9; done
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  cd gphoto2-2.4.14/
 
 
= Tweaking NX =
 
 
 
Almost everything is very fast and low-[[latency]] with NX. However, Window resizing effects are slow. Switch them off, e.g. in [[KDE]] using kpersonalizer:
 
 
 
'''kpersonalizer -> chose ''Next'' till you come to the ''Eyecandy-O-Meter'' -> Show details -> Window Moving/Resizing Effects'''
 
 
 
= KDE 4 =
 
 
 
In order to run KDE 4 in an NX session, you may need to change the call <tt>startkde</tt> to <tt>startkde4</tt> in /usr/NX/etc/node.cfg and /usr/NX/scripts/setup/nxnode. This is the case if your KDE is started with the [[command]] startkde4.
 
 
 
= TroubleShooting =
 
To get logging output to /var/log/messages, edit /usr/NX/etc/node.cfg. Set
 
SessionLogLevel = "6"
 
and you can read NX' log from /var/log/messages. Let's look at this one:
 
<pre>
 
Jan  8 17:07:18 mars NXNODE-3.2.0-11[30374]: ERROR: run command: process: 30461 died because of signal: 9 Logger::log nxnode 3844
 
Jan  8 17:07:18 mars NXNODE-3.2.0-11[30480]: Directory '/home/tstaerk/.nx/C-mars-1019-7C3118AB902BD0DFE9CEC4AC7631B407' renamed into '/home/user/.nx/F-C-mars-1019-7C3118AB902BD0DFE9CEC4AC7631B407' for further investigation Logger::log nxnode 6215
 
</pre>
 
Now you [[cd]] to /home/user/.nx/F-C-mars-1019-7C3118AB902BD0DFE9CEC4AC7631B407 and look at the log files.
 
 
 
== Connecting to ... ==
 
When I had this error that NX showed nothing but connecting to... it helped to kill nxd.
 
 
 
== The NX service is not available ==
 
;Symptom 1: When logging in you get the error message
 
The NX service is not available or the NX access was disabled on host ''hostname''
 
When clicking onto "Detail" you get
 
NX> 200 Connected to address: 10.20.68.47 on port: 22
 
NX> 202 Authenticating user: nx
 
NX> 208 Using auth method: publickey
 
NX> 204 Authentication failed.
 
For every log in attempt you find the following message in /var/log/messages:
 
2013-11-27T08:55:47.608389+01:00 ls3523 sshd[19975]: Connection closed by ''10.20.68.47'' [preauth]
 
There is no file /usr/NX/home/nx/.ssh/authorized_keys, only a file /usr/NX/home/nx/.ssh/authorized_keys2
 
;Solution 1: Copy the file authorized_keys2 to authorized_keys:
 
tweedleburg:/usr/NX/home/nx/.ssh # cp authorized_keys2 authorized_keys
 
tweedleburg:/usr/NX/home/nx/.ssh # chown nx authorized_keys
 
and it works
 
 
 
;Symptom 2: When logging in you get the error message
 
The NX service is not available or the NX access was disabled on host ''hostname''
 
When clicking onto "Detail" you get
 
NX> 200 Connected to address: 10.20.68.47 on port: 22
 
NX> 202 Authenticating user: nx
 
NX> 208 Using auth method: publickey
 
NX> 204 Authentication failed.
 
For every log in attempt you find the following message in /var/log/messages:
 
2013-11-27T08:55:47.608389+01:00 ls3523 sshd[19975]: Connection closed by ''10.20.68.47'' [preauth]
 
If you call nxssh it does not work.
 
;Solution 1: Make sure nxssh works:
 
yast -i openssl-devel libjpeg62
 
 
 
== wrong colors ==
 
Sometimes you see wrong colors in your NxClient like this:
 
[[Image:Snapshot-wrong-colors.png]]
 
In this case, disable compression.
 
 
 
== Connected to ... ==
 
'''Symptom:''' Your attempt to connect to NX fails after nxclient output "Connected to ''computername''". You get the error message
 
The NX service is not available or the NX access was disabled on host ''computername''
 
When you click on "Detail" you get something like
 
NX> 203 NXSSH running with pid: 7266
 
NX> 285 Enabling check on switch command
 
NX> 285 Enabling skip of SSH config files
 
NX> 285 Setting the preferred NX options
 
NX> 200 Connected to address: 192.168.178.3 on port: 22
 
NX> 202 Authenticating user: nx
 
NX> 208 Using auth method: publickey
 
NX> 204 Authentication failed.
 
 
 
'''Solution''', in this case for SUSE Linux 12.2 and NX 3.5:
 
ln -s /usr/NX/home/nx/.ssh/authorized_keys2 /usr/NX/home/nx/.ssh/authorized_keys
 
 
 
== Downloading the session information ==
 
'''Symptom:''' Your NX connection fails after the message "Downloading session information". When you set SessionLogLevel to 7 in /usr/NX/etc/node.cfg and try again you find in /var/log/messages something like
 
NX> 596 /usr/bin/xauth: /home/''user''/.nx/C-''hostname''-1007-E856077CEA415BD723D2013A45400AC9/scripts/authority:3: 
 
  bad display name "''hostname'':1007" in "add" command
 
 
 
'''Reason 1:''' NX expects to be able to connect to the localhost by using its hostname.
 
 
 
'''Solution:''' Make sure you can ping your local host like this:
 
ping $(hostname)
 
 
 
'''Reason 2:''' You do not have enough disk space left.
 
 
 
'''Solution:''' Free up some disk space.
 
 
 
== Established display connection ==
 
'''Symptom:''' Your NX connection fails after the message "Established display connection". The log file on the server under
 
/home/''user''/.nx/''latest''/session contains a string
 
Error: Aborting session with 'Could not open default font 'fixed<nowiki>''</nowiki>.
 
 
 
'''Solution 1:''' It may be the X Font Server. Start it
 
  /etc/init.d/xfs start
 
 
 
'''Solution 2:''' Copy over the folder /usr/share/fonts/misc from your client to the server.
 
 
 
== Server configuration error ==
 
You get
 
Server configuration error. Cannot log in.
 
Please contact your system administrator.
 
 
 
'''Solution 1:''' you need: a home dir for the user
 
 
 
'''Solution 2:''' your harddisk is full, make space
 
 
 
== Maximum number of allowed users ==
 
'''Symptom:''' When logging in you get the [[error message]]
 
Reached the maximum number of allowed users on
 
this server.
 
 
 
'''Solution:'''
 
* add your user to /usr/NX/users.db
 
vi /usr/NX/etc/users.db
 
* restart the NX service using the command
 
/etc/init.d/nxserver restart
 
 
 
== not available ==
 
If you get an error message that NX is not available or has been disabled, re-install it:
 
/usr/NX/bin/nxserver --uninstall
 
/usr/NX/bin/nxserver --install
 
 
 
== maximum session number exceeded ==
 
List your user sessions with
 
nxkill --list
 
Then kill them like this:
 
# ps -A | grep -i nx
 
  3435 ?        00:00:00 nxserver
 
  3477 ?        00:00:00 nxssh
 
  3481 ?        00:00:00 nxnode
 
  3576 ?        00:00:03 nxagent
 
  3579 ?        00:00:00 nxserver
 
  3586 ?        00:00:00 nxssh
 
  3594 ?        00:00:00 nxnode
 
28689 ?        00:00:00 nxserver
 
28732 ?        00:00:00 nxssh
 
28737 ?        00:00:00 nxnode
 
'''''28830'' ?        00:25:54 nxagent'''
 
28833 ?        00:00:00 nxserver
 
28838 ?        00:02:01 nxssh
 
28848 ?        00:00:00 nxnode
 
# nxkill --kill --pid ''28830''
 
 
 
=== no sessions are active ===
 
 
 
==== enable users ====
 
If you cannot log in to the NX server and get an error message like
 
maximum session number exceeded
 
AND
 
nxkill --list
 
shows you there are no active user sessions, this can be the case because your user is not enabled to log in. To find out if your user is enabled to log in, use
 
nxserver --userlist
 
You will be able to log in with all users that are shown then.
 
 
 
==== Re-install NX ====
 
If no sessions are shown, you will have to re-install NX:
 
  /usr/NX/bin/nxserver --uninstall
 
/usr/NX/bin/nxserver --install
 
 
 
= See also =
 
* [[control A computer]]
 
* http://www.nomachine.com - where to get NX
 
* http://www.linuxquestions.org/questions/linux-software-2/nx-server-access-problem-930551/
 
 
 
[[Category:Guides]]
 

Revision as of 18:44, 11 August 2012

gphoto2 is a utility to download pictures from a digital camera.

To build and install it, find out your distribution and proceed accordingly

SUSE Linux 12.1

yast -i libgphoto2-devel
cd
tar xvzf Downloads/gphoto2-2.4.14.tar.gz
cd gphoto2-2.4.14/