New RACHEL-Pi image in the works

The RACHEL-Pi image on our FTP servers is almost a year old, so it’s time to update it with the latest goodies. I’ll be working on that over the next couple weeks. We’ve done a lot of updates in the past year - most notably adding functionality to add/remove/update modules through the RACHEL Admin panel. Our RACHEL-Pluses are already shipping with these updates, and I’m looking forward to bringing them to our entry-level server.

If there’s any other requests for the next RACHEL-Pi, just post them here.

Thank you for letting us know!

Once the new image is complete, what differences will remain between Rachel Pi & Rachel Plus?

Software Capability of Plus over Pi:

  • Remote access and updates if/when plugged into the internet ?
  • Password protected teacher portal to easily upload PDFs, Movies, and other files ?

Hardware Capability of Plus over Pi: (obviously remain)

  • Up to 50 simultaneous users
  • Extended WiFi range
  • 500GB of available storage (~300GB is pre-loaded by us)
  • 5 hour+ battery life

Related Questions:

  • With Pi 3, is SD card corruption on loss of power still an issue? In my view, this is the biggest reason to go for a Plus (At least, I assume that the Plus will shut-down nicely, or at least not cause data loss, when the 5 hour battery runs out. Correct?)

  • Hard drives (Such as WD Pi Drive, which looks like a nice option) can be more easily added to the Pi 3 and would be more relevant if you are update the software to the full Plus capabilities. Any thoughts? (Corruption on power loss would still be my main concern.)



The new Pi image will bring remote access and online updates, the first item listed. It will also include the latest Raspbian operating system software (for security and performance) and some updated content modules.

The password protected portal is something made by Intel specifically for the Plus hardware, so that won’t be on the new Pi. We do have on our list a project to replicate that functionality for the Pi, but that would be down the road and would come in the form of a RACHEL module that could be installed pretty easily later.

The rest of the hardware items, as you said, will obviously remain :slight_smile:

For the related questions - unfortunately we don’t have any new info on SD card corruption. We do provide a manual shutdown control in the RACHEL admin so that you can minimize the problem, but it would still suffer under a power outage, and from the general issue that SD cards are not as durable under continuous usage as HDs.

Funny you should mention the WD Pi Drive - we just met with them last week and they gave us some test units. Looks like a cool device. The big advantage there is that the SD card is just used to boot, but all activity after that takes place on the HD. They claim that doing that minimizes the SD card corruption issue. My understanding is that even under a power outage, the HD is unlikely to sustain damage. I think we would need to make a different RACHEL image, though, that properly stored all the files on the HD instead of SD. If you try it and get there before me, we’d love it if you shared :slight_smile:

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I am running RACHEL on a Linux box.
I am exploring RACHEL on a Pi.

I am interested in exploring storage options, as a 64GB card is expensive (at least, in $/GB terms), and doesn’t really allow for lots of content.

My proposed solution is:

  1. Much smaller SD card, suitable to Raspbian and possibly RACHEL “operating system” elements.
  2. Connect an external drive
  3. During installation, set the server public HTML folder to the external drive

Done, or am I missing something fundamental?


adeptdigital, I think this is exactly what you need:

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I have installed Rachel on a PIDRIVE and every works great with the exception on KA-Lite it give an error of: {“error”: “Can only handle default language changes through POST requests”}

Not sure how to correct. Also in the administration screen shows the modules ignored with en-kalite ess not having a file in index.htmlf.

Any ideas?


@Tim can you give a screen shot of the error you’re getting? Trying to determine if KA-lite is successfully installed. If so, there’s probably some work of configuring the correct location to drop the video files. I don’t have that hardware handy, so a bit difficult to diagnose.

Here are the screen shot of the error.

Here is the screen shot of the ignored module on the Admin screen.

Hi Tim,

That “Can only handle default…” error is because RACHEL includes a custom multi-lingual patch for ka-lite. You can install the patch like so:

wget -q -O /usr/lib/python2.7/dist-packages/kalite/i18n/

And then:

kalite restart

Double check the directory /usr/lib/python2.7/dist-packages/kalite/i18n/ exists – on some installs it can be in /usr/local/lib instead.

This patch was submitted to the kalite team and included in the 0.17 release, but if you’re on 0.16.x or earlier, you’ll need to install it manually.

The later messages about ignored modules:

lost+found is a linux directory that appears after a hard drive repair. In this case it was created in the modules directory, so RACHEL is just saying that it sees that in the modules directory, but it isn’t a valid module. You can safely ignore that message, or if you want to make it go away you can delete the directory /var/www/modules/lost+found.

The similar message about en-kalite-ess – is it possible that there was an incomplete install of that module? It sounds like you installed the full en-kalite instead (the -ess stands for “essential” and is a subset we use on the 64GB RACHEL-Pi). If it is not needed you can just delete that directory too.

In any case, try the multi-lingual patch and let me know how things look!

@adeptdigital I don’t think you are missing anything. I am doing just what you proposed only I installed apache2 as the web server and did not install the RACHEL “OS” (but I want to try it next). I am able to serve up most of the RACHEL content, but I have not installed kiwix yet.

I have set my DocumentRoot to a folder on my external drive and made the appropriate .conf edits. This is working great. Did you also pursue an external drive for your content?

This is what I get when running it:

wget -q -O /usr/lib/python2.7/dist-packages/kalite/i18n/
/usr/lib/python2.7/dist-packages/kalite/i18n/ No such file or directory

When I boot the system to broadcast it shows KA Lite but the selection of any of the links gives the “Can only handle default…” error still.

Did reinstall the module with not luck.

The KA Lite module is loaded in my system in home/rachel-modules/en-kalite.

Here is the full path created in my system with the en.js script:

There is not a kalite in /usr/lib/python2.7/dist-packages/kalite/i18n/ OR /usr/local/lib.

Sure I am missing the patch but the upper link did not create it.

Hope this makes since.

Still working with it.


Ok, gotcha. I guess the installation path is different on your setup. One thing to note is that the ka-lite content is separate from the software. What I mean is that while the module resides at /home/rachel-modules/en-kalite, that is just videos and some support files, and does not include the actual ka-lite code which is installed elsewhere in the system. The brute force approach to find it:

find / -name

That’ll show you where the file we’re replacing is on your system. Then you need to modify the second path in that wget command. Give this a shot and let me know what you find!

Tried the fix but `’: No such file or directory.

Wow, then I’m stumped. If we can’t find that file then don’t know where that error message {"error": "Can only handle default language changes through POST requests"} is coming form since that is generated by on my system.

If you have any clues where the kalite software got installed, we’d need that to continue.

Alternately, if you can upgrade to 0.17, this patch is included and that error message removed.

What would be the best way to attempt the upgrade?


The official instructions are here – but you’d have to talk with the kalite team if you run into problems with that, as I have not tried it myself. I have only done fresh installations.

Kindly send me the 32gb image file of RACHEL PI. Thank you.