Robert Pogson

One man, closing all the windows.

Posts Tagged / LTSP

  • Apr 16 / 2014
  • 0
Linux in Education, Teaching, technology

GNU/Linux Works In Computer Labs In Greece

After years of using GNU/Linux in schools and introducing it to many students and teachers,“All these tools together, Sch-scripts for setting-up PC labs, Epoptes for managing them, and LTSP are used in more than 500 schools, all over Greece. The free and open source solutions help save teachers valuable time. One grateful teacher posted a testimonial on the support forum for Sch-script in 2010: "Within one hour, a PC lab set-up which had been giving me all kind of headaches (8 computers with Windows 2000 and dozens of problems) became operable… from my laptop! Tomorrow, I am doing the first real test-drive with students, but it was amazing how fast and easy everything was. I’m speechless. Now I can share my desktop with all the lab PC users, and monitor them, it is incredible."” I became skilful enough to set up a lab in an hour or so, replacing that other OS with something that worked. That’s becoming “old school” these days with many distros provide setting up the software through the package-manager.

Now even more of the configuration and additional tools are all available by a set of scripts developed in Greece. 500 schools is a whole bunch more than I worked. GNU/Linux works in education. It can work anywhere. Finding the recipes for all this and sharing is obviously more efficient than buying solutions sold by M$ and “partners” that cost too much or don’t work at all sometimes. The world can and does make its own software better than those guys. This is just another example of doing IT the right way.

See Computer lab management tool in over 500 Greek schools.

  • Dec 29 / 2013
  • 1

Dave At City of Largo Reports Looking At NX and LibreOffice 4.1

While the trolls here constantly tell us how essential that other OS is people in the real world keep rolling along comfortably with GNU/Linux, LibreOffice and making unfettered (by M$’s EULA) use of the hardware they own.

“We jumped on LibreOffice 4.1 at 4.1.1 to solve some issues and improve file filters versus 4.0. Out of 800 users, about 20 had to be rolled back for various bugs, which is normal and expected. With release 4.1.4 we have been able to finally get everyone off of 4.0.”

For those who don’t know, Largo never used that other OS much so they were never locked in. They just went from a UNIX OS to GNU/Linux and never looked back. They use a cluster of huge powerful servers to run GNU/Linux thin clients. They can have hundreds of sessions open on a single server and have servers specialized for running a single application like LibreOffice. Single point of failure indeed… Chuckle. Instead of failure Largo has success, saving many $millions and getting great performance. They only have to “work” on a few servers and the thin clients just keep doing their thing. It’s not rocket science. Just keep a few servers working hard and many clients idling and performance happens with GNU/Linux.

The real puzzle is not why Largo is using GNU/Linux. The real puzzle is why many others continue to use that other OS at great expense and endless problems. My experience in schools using similar technology was that the effort required to keep the system running smoothly dropped an order of magnitude using GNU/Linux. That’s why Largo has the time to tweak their servers. They don’t have to tweak their clients.

See Dave Richards – City of Largo Work Blog: Thinning Thin Clients, And Other Projects.

  • Apr 07 / 2013
  • 20

How to Implement FLOSS

I found an interesting article about how businesses can use GNU/Linux thin clents. It covers all the important stuff…
“Implementing thin-client solutions achieves a number of benefits, including lower costs, easier maintenance, and an enhanced customer presence. Costs are reduced because the client’s hardware needs are less than solutions that require full, local-client functionality. Maintenance is easier because all the software maintenance is done on the server, because no software resides on the thin client itself. In fact, some businesses using thin-client solutions simply replace a failing thin client rather than perform maintenance on it. Again, because no software runs on the client, no configuration is needed on the replacement hardware. Finally, a thin-client solution can enhance customer presence because it lets a business safely provide access to customers within an environment that can be fully controlled and secured from the server.”
see How to Implement Open-Source Solutions: Thin Clients | Systems Management content from iPro Developer
…except there’s something terribly wrong with assuming the purpose of the thin client is to run applications on M$’s OS. A computer running GNU/Linux can do anything that a computer running M$’s OS can do but GNU/Linux will be better, faster and cheaper. That’s why TFA suggest using GNU/Linux on all the other infrastructure.

It’s past the time that we should assume the use of applications that are M$-only. That’s just plain silly. More computers were shipped with Android/Linux last year than M$’s OS. Why not assume Android/Linux “apps”? Why not replace M$-only applications with FLOSS applications that the world can use for $0? The world is huge compared to M$ and “partners” and can make its own software. The world has better office suites (better compliance with open standards), better browsers (faster, less malware), and better servers than M$ and “partners” (faster, greater uptime and throughput). Why the Hell should we put up with applications that run only on that faulty/defective-by-design OS?

Wake up! FLOSS should be the default solution and applications on that other OS a temporary solution while alternatives are found/created.

  • Mar 28 / 2013
  • 0

New in Linux 3.9

H-Online has a neat preview of Linux 3.9, now in the works.

My favourite item, additional caching ability for Linux:
“Device mapper, which is used by the logical volume manager (LVM) but can also be used independently, now includes a cache target called "dm-cache" (1, 2, 3). This option enables a drive to be set up as a cache for another storage device, for example, an SSD as a cache for a hard drive.”
see Kernel Log: Coming in 3.9 (part 1) – Filesystems and storage

Caching of files in RAM has always been a huge plus for Linux in my terminal servers I installed in schools. RAID 1 was very useful but adding an SSD cache to that would be amazing. Students I used to advise to be careful when clicking should now wear seatbelts and helmets. ;-)

  • Dec 13 / 2012
  • 1

Open Source, Limerick City Council

“In an effort to reduce software licencing costs, Limerick City Council is fully committed to adopting open source solutions that prove to be value for money.”

via Open Source, Limerick City Council.

Amen. Doing IT right as a local government involves getting the most bang for the $ and FLOSS does that in a big way. Costs of creating, distributing and maintaining software are all minimized with FLOSS and there’s nothing that cannot be done with the FLOSS OS, GNU/Linux. When Limerick is ready to migrate its desktops, I recommend Debian GNU/Linux because of its huge repository, slick package manager and depth and breadth of application.

  • May 10 / 2009
  • 2
Linux in Education, technology


Resistance to change is a defensive measure we all have to prevent wasting time learning something new for the sake of change. It can go too far. It has gone too far the way many retain that other OS. You know the kind:

  • never used anything else
  • hires someone every year to re-install/delouse that other OS or pesters an acquaintance to do it for less
  • accepts the idea that computers slow down (HAHAHA!)

These behaviours are irrational acts of the lazy. They are not idiots incapable of deeper thought. They are just using poor judgment and are resistant to change. The Blog of Helios does use the “idiot” term today. I guess enough resistance to change warrants the term but I think “stupid” is more appropriate. There cannot be that many idiots in the gene pool or we would not have gotten this far as a species.

I try not to be stupid but I did use that other OS for far too long:

  • I used a dozen different architectures of hardware, some even without an operating system, just stand-alone programmes
  • I like the old days of automobiles when anyone with wrenches and screwdrivers could fix their own vehicle. I try to fix my own PC and I rarely am stopped
  • my computers do not slow down. I run GNU/Linux. It has no brakes.

I had an example of this last item in operation in my school this week. I converted a lab to use GNU/Linux by adding a 5 year old PC as a terminal server and converted the 20 PCs in the lab to thin clients. It was a struggle because of various hardware and software issues like having to edit the boot loader configuration of that other OS to preserve it (Why? Some resist change…), many hardware problems in the old equipment (Remember 4MB video cards?), but it was worth it:

  • booting of clients in 30s instead or 3 minutes
  • login takes 5s instead of a minute or so
  • the largest application opens its window in 2s

This weekend, I added four more clients. The users of that other OS, who find they have to have the latest processor just to keep the bloatware moving fast enough cannot understand how one old PC can give 24 people good performance simultaneiously but it is easy if you

  • waste no cycles doing M$’s bidding
  • do not waste cycles running malware
  • do not clog network connections with spam
  • avoid features like “roaming profiles” which suck the life out of your network

So, including a switch from that other OS, my old PCs actually speed up! Isn’t that a refreshing change? I converted ten year old clients and a five year old PC into something wonderful. Students are excited about it and the increased performance is an obvious reward for the effort of changing. Most people are not stupid. They just need a little guidance. By asking the old boxes to do less, they get it done sooner. Simple concept. It works.

I believe if you cannot describe in numbers knowledge is of an uncertain kind:

  • the clients use 48 MB of RAM to do the job now instead of 384 MB and swapping madly with XP
  • the clients use only about 20% of their CPU time when busy
  • the clients need only about 2 megabits/s of network bandwidth each so there is no bottleneck at the gigabits/switch/ NIC on the server
  • the server PC has 2 gB RAM and runs at about 50% CPU utilization on AMD64 1.8 gHz

Those used to their machines dragging with fragmented file systems and the like would appreciate a machine giving snappy performance with 2000 context switches per second. There is no bottleneck in this system except RAM is a little tight (swap reached 1.6 gB), but then I am running a LAMP stack on the same machine… Those who object that the students are not all working on 200 MB images with GIMP are being picky. Students read, write and think. This system works for them.

Want to take a tour of the lab? What have I left running?

sh-3.1$ ssh old
Last login: Fri May 8 21:20:34 2009 from
pogson@old:~$ su
old:/home/pogson# nmap -sP 192.168.0.*

Starting Nmap 4.62 ( ) at 2009-05-10 09:12 CDT
Host old-o07 ( appears to be up.
MAC Address: 00:0D:88:36:C0:F3 (D-Link)
Host old-o08 ( appears to be up.
MAC Address: 00:0D:88:36:C3:19 (D-Link)
Host old-o12 ( appears to be up.
MAC Address: 00:15:E9:B0:FD:12 (D-Link)
Host old-o15 ( appears to be up.
MAC Address: 00:50:BA:AA:54:79 (D-link)
Host old-o16 ( appears to be up.
MAC Address: 00:50:BA:86:5E:B5 (D-link)
Host old ( appears to be up.
Nmap done: 256 IP addresses (6 hosts up) scanned in 1.697 seconds
old:/home/pogson# for f in 7 8 12 15 16;do echo $f;ssh 192.168.0.$f cat /proc/cpuinfo|grep z;done
cpu MHz : 451.035
cache size : 64 KB
clflush size : 32
cpu MHz : 863.875
cache size : 256 KB
clflush size : 32
cpu MHz : 451.034
cache size : 64 KB
clflush size : 32
cpu MHz : 451.040
cache size : 64 KB
clflush size : 32
cpu MHz : 601.396
cache size : 256 KB
clflush size : 32

There. The typical CPU is 450 MHz and the caches are 64kB. They make great thin clients and lousy clients for that other OS. Should we chuck them and pollute the planet? Should we burn less fuel by switching to modern hardware? Yes, if we use thin clients and a hot new server, the performance will be a bit better and we will use a lot less power, but this is what we have with which to work. We do the best we can and the students appreciate it.

  • Dec 17 / 2008
  • 0
Linux in Education, Uncategorized

Excellent Article at Heise on LTSP

see TFA.

TFA is concise, well-written and gives tons of links to further information about LTSP, the Linux Terminal Server Project, which is a great solution for extending the power of a newer PC or server and for centrally managing PCs at home, school or in business.

I first used LTSP in 2003 as implemented in the distro, K12LTSP. The LTSP team, and several distros have turned this combination of x-window-system, DHCP/BootP/TFTP/NFS into a means of booting diskless clients. This saves thousands of dollars in capital costs for even a small installation and lightens the load on the system administrator by a large factor.