Session management improved

After an  upgrade to Ubutnu Intrepid and NX 3.3 I have observed that session management has improved a  lot.

With earlier releases, exiting and reconnecting could render the session useless due to the “famous” black screen. If you look at my previous postings a rant about that is there. It seems the combination og Ubuntu Intrepid (GNOME 2.24) and NX 3.3 is a godd combination. I have tried to connect, logof (not disconnect) and reconnect many time this weekend, and the session is starting as expected every time. Very godd news which lessens the admin burden a bit.

Problem with 64bit NX client

In general I am pleased with the NX server. I have recently changed 2 things, almost simultaneously, upgrade Ubuntu Gutsy -> Hardy -> Intrepid aka. Ubuntu 8.10. This was done in order to deliver the best possible desktop interface for my users.

The upgrade was uneventful and the NX server did not require any change at all, very nice.

My users, typically running Windows or Macs at home, have no problems connecting to the upgrade Ubuntu system. At home I now have a quadcore running Ubuntu 8.10 64bit. I have problems with the 64bit nx client, it connects fine and displays the desktop but after that it apparently loses the connection. Better file a bugreport with nomachine.

Still session problems

Hmm.

Every now and then my tester has the “black screen” problem. He uses a Nexterminal thin client with the default NX client 2.0.1. When he experiences the black screen, he has to reboot the terminal. Now very nice. A server with 20 simultaniously users will generate a lot og support calls and lack of confidence.

I am having similar problems with the existing Citrix setup, *but* that is a very old and tires setup now.

In order to insure a successful logon I have now written a small CfEngine controlfile whice does some cleaning up every night at 4AM

It goes like this:

#
# Cfengine configuration
# Settings for NX Terminal Servers
# $Rev: 372 $
control:

actionsequence = ( shellcommands )

classes:

shellcommands:

# Terminate NX processes
srvdk10.Hr04::
“/bin/kill $(/bin/ps ax |/bin/grep nx|/bin/grep -v grep|/usr/bin/awk ‘{print $1}’)”

# Clean up session files in /tmp
srvdk10.Hr04::
“/usr/bin/find /tmp/ -maxdepth 1 -type d -regex ‘.*gconfd-.*’ |/usr/bin/xargs -i rm -fr {}”
“/usr/bin/find /tmp/ -maxdepth 1 -type d -regex ‘.*keyring-.*’|/usr/bin/xargs -i rm -fr {}”
“/usr/bin/find /tmp/ -maxdepth 1 -type s -regex ‘.*mapping-.*’|/usr/bin/xargs -i rm -f  {}”
“/usr/bin/find /tmp/ -maxdepth 1 -type d -regex ‘.*orbit-.*’  |/usr/bin/xargs -i rm -fr {}”
What it is supposed to do is to terminate all NX processes, and then remove the blocking session files in /tmp

Now testing daily

After some initial problems, which turned out to be a defective switch, my testuser is now using the NX server on a daily basis. He is generally satisfied and remarked en passent the other day that he liked the new system better that the old and tired Citrix system. That remark felt good and makes me think even more seriously about migrating to the NX  terminal server.

Today I have installed NX client on his privately owned notebook, so he can access the NX server from home also. He uses a 3G 3Mbit mobilephone link and the interface worked nicely in that setup.

There is one very annoying “feature” with the NX software. Sometimes, if the NX server was terminated hard – think power outage – the client gets a black screen instead of his desktop. Googling a bit makes it apparent that other people experiences the same problem. It is very annoying, because it need the root user to remove some files from /tmp, before the client gets his desktop. Nomachine really ought to fix this very soon.

I use x3270 for terminal work, it anybody knows about a fine x3270 client with a more polished interface than x3270, I am very interested.

Stattus so far is good, NX seems to work as promised.

NX single signon – ready for testing

Today I finished setting up the NX login for my testuser. The following is now working:

• winbindd configured  to authenticate againts the NT4 BDCs
• NX logon tested, user setup polished so that Thunderbird, Firefox and OpenOffice feels like the testuser is accustomed to
• Fiddling around with mounting of fileserver shares, CIFS didn’t play along today for some reason, using smbfs temporarily

Winbind notes

‘ winbindd_idmap.tdb’

I don’t have an LDAP server to store Windows –> Linux idmapping on, so the winbindd on the fileserver and the winbindd on the testserver assigned different uid to logins. Fixed that by copying ‘ winbindd_idmap.tdb’ from the fileserver to the testserver

‘logging on NX ‘

In order to let the testuser logon to the testserver, it is necessary to have authencating done by the Windows BDC and have pam set up properly. The following 2 documents showed the way:

1. David Christian’s blog on Actice Directory authenticating 

2. No Machine document on the same subject

NX black screen

I have been using the NX terminal server on and off for a month or so witout any problems. Today when testing with a DesigNEX-I thin client, weird things started happening. The thin client has a NX 2 client on board and the server is a version 3, perhaps that is the problem. Anyway, when logging on after a few logons and logoffs the screen was black. I am authenticated  and the red NX logo is shown and after that…blackness. A few searches on Google suggested cleaning /tmp which I did, and after that the Ubuntu GNOME desktop is shown.

Mount fileserver shares at user login

Libpam-mount

Received a new book from Amazon today, Ubuntu Hacks, and a short notice on libpam_mount caught my eye.

Apparently libpam-mount can perform a mount when a user logs in. That is very nice as I make the user’s home directorie on the fileserver available as a “z-drev” in each user’s home. Will investigate that in more detail.

The fileserver has a share called “data”, which contains files shared among the users. Each user on the new Ubuntu Terminal Server will have a directory “data” as mountpoint for the fileserver share.

 How to mount

For now I have a script mounting the fileserver

#! /bin/bash

# SRVDK01/profiles
mount -t cifs //srvdk01/profiles /home/DOMAIN/kv/.profiles -o netbiosname=SRVDK10,iocharset=utf8,credentials=/root/.smb-kv.txt

# SRVDK01/data
mount -t cifs //srvdk01/data /home/DOMAIN/kv/data -o netbiosname=SRVDK10,iocharset=utf8,credentials=/root/.smb-kv.txt

where /root/.smnb-kv.txt has the following content:

username=DOMAIN/kv
password=thepassword

That should be easy to use in libpam-mount, I guess

Starting out on the quest

The first post in this blog is an overview of a test I will do in the coming months. It is about upgrading an old NT4 domain installation to something more modern and stable.

Overview of current setup

• NT4 domain controller runnng on an old HP Server
• 3 Windows 2000 with Citrix Metaframe 1.8 ontop
  • Typical Applications for the majority of users are:
  • Firefox
  • Thunderbird
  • OpenOffice
  • An x3270 client
  • Software delivered by various carrier companies, it used to be Windows software, but web applications are replacing the installed software packages
  • A few people run the accounting software, salary software etc.
• An NT4 Terminal Server whose only mission nowadays is to serve an old CRM application to the sales department
• A Samba fileserver serving shared files and Windows user profiles (Debian Sarge, soon upgraded to Etch)
• There are many other servers running in the installation but they are not interesting in this experiment

I have 4 different upgrade paths in mind:

Common part of the new setup is a Windows 2003R2 Domain Controller

1. Citrix Presentation Manager 4.5 + thin clients
2. Ubuntu/NX TErminal Services + thin client with RDP to domain Controller for necessary Windows programs
3. Go Global – don’t know a thing about it
4. Standalone workstations

The solution I would like to implement is #2. #1 is very expensive and probably overkill, #3 is unknown to me at this point in time and #4 is a maintenance nightmare in the future. #4 does have the advantage of more processing power and just an annoyance when a machine breaks down. The solution Ubuntu/NX is very appealing as I am much more comfortable using a linux server than a Windows one.

In order to find out if solution #2 is viable, I will setup an environment of type #2 and let one of my colleagues use the system in the coming months. Time will tell if I can make it work.