Sunday, June 6, 2010

Unfinished business: Ubuntu LTSP over Wifi

For some time now, I have been working on figuring out LTSP (Linux Terminal Services Project) over wifi. The idea is simple (aren't they all):
  1. Modify the Initial Ramdisk for the PXE boot image to include the Wifi drivers
  2. Update the start up script to load the driver
  3. Connect to wireless router prior to issuing dhcp request
Since wireless drivers are being loaded at boot time, the true PXE nature is lost. Also, the kernel and the initial ramdisk would reside on the client computer's hard disk. However, the computer would boot directly into the LTSP client, using the LTSP servers resources for storage and processing and only using the client machine's inputs and outputs.

When I added the wifi drivers and all the dependencies, the setup did not work. There was still a "not so obvious" component missing. So, I decided to start with a fully loaded initial ramdisk and work my way backwards from there, by removing modules that seemed not necessary. I replaced the /lib/modules/`uname -r` folder of the LTSP ramdisk with that from my desktop installation. Initial tests resulted in a successful startup of LTSP client on my laptop and in Virtual Machines. This also caused my compressed ramdisk image to increase from 8 MiB to about 30 MiB in size.

Now the real challenging part. My laptop is not the intended target for this test. I want to run the customized LTSP client with wifi enabled on old Fujitsu tablets. They have 128 MB in RAM and 500 MHz processor. Yes, very ancient hardware, but that is where the finalized clients will reside. First trials on the tablets failed. After testing on virtual machines with limited resources, I quickly realized that RAM was the problem. Since I can not increase the RAM in those tablets, I'll have to shrink the ramdisk by a significant size.
I haven't worked on this in past few days. Hopefully, I can pick up from where I left in coming days.

Progress on this topic can be followed on the following pages:
Ubuntu LTSP over Wifi (Continued)
Ubuntu LTSP over WIFI - TP-LINK TL-WN422G
Ubuntu LTSP over WIFI - TP-LINK TL-WN422G - Update

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