Robert Pogson

One man, closing all the windows.

Posts Tagged / LTSP schools

  • May 12 / 2009
  • 0
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Inversion

I woke up this morning and realized I had created an inversion. No, not a condition of the weather likely to result in a storm, or an inverted population of excited atome likely to lase, but an inverted population of students, users of PCs.

You see, in this school there are two labs.

For higher forms of life:

  • five year old PCs with XP sp3, 1 gB, 1.9 gHz CPU
  • boot time 2 minutes

For lower forms of life:

  • ten year old PCs with XP sp3, 384 MB, 330-850 MHz CPU
  • boot time 3 minutes

It is the natural order of things that the lower forms of life are the bottom feeders, living off what filters down from above.

The lab for the lower forms of life was a disaster. Every time I visited it, I would take 20 minutes putting cables back in place because students believed their “mouse was not working” because XP froze or was too busy to pay attention to them. Of course, XP put virus scanning as a higher priority and 2003 would put in random waits just for fun.

The lab upstairs works marginally. Power supply failures are its main problem.

The inversion? Now, the PCs in the lab downstairs run as thin clients and applications run on a newer PC, also 5 years old, but running Debian Lenny GNU/Linux on an AMD64 3000 with 1.8 gHz clock, 2 gB RAM, gigabit/s NICs and RAID on larger hard drives… So, the lab downstairs now

  • boots in 60s with login in 5s (POST takes 15s!)
  • applications load in 2s
  • has 24 machines instead of 22 because I was able to install tiny drive in a few more failed machines. The drives are used for the bootloaders.
  • is several times faster than the lab upstairs

I took a walk around the old lab while writing this. One machine would not boot because of a loose ethernet jack and one had a mouse failure, leaving 22 machines fully functional when they were down to 17 or so on many days in the past. The lab is much more solid as well as being fast. Vista or 7 does not work here. GNU/Linux does. 87 users think so.

On top of the performance, we have iTalc for the teacher to control the lab. Not all the features work, but the teacher can demonstrate and monitor very well. I can give the teacher a button to shut the lab down. Locking the machines already works.

So, there is an inversion. The natural way of things is turned upside down. The lower forms of life have better IT. Thank you, LTSP.org, GNU/Linux and Debian. What will this instability produce? I do not know, but I expect there will be some demand for newer IT to be GNU/Linux because they can see the improvement using GNU/Linux instead of that other OS. The machines in the upstairs lab will never run an upgrade from that other OS. They may run GNU/Linux or be scrapped in favour of modern tiny thin clients. That would be sweet as we run on diesel power. The power savings alone would pay for the changeover.

The cost of the upgrade to the downstairs lab was mostly in downloading software which was incredibly slow on our ISP and struggling to authenticate against AD. What a waste of time. Students would be better off with separate accounts. 2003 still has long pauses… PDC will not answer the call so the BDC responds after a timeout… arghhh! Give me simple LDAP any day.

The new server in the old lab is my old PC which I upgraded when I prepared for the conference in February. I kept my case and power supply but donated the guts which, with a new power supply, went into a failed PC from the newer lab.