USB Reliability

So we’re putting a hold on selling RACHEL-USB for the moment - we’ve found that the USB drives we were using were not very reliable. We want to ship it on a USB with a write-protect switch, because we know how often USB flash drives become a vector for computer viruses. However there are very few USB drives with write-protect switches these days.

Right now I’m testing out the following under USB 3.0:

  • 32GB Netac U335 - this is what we’ve been using - inexpensive, with write protect switch
  • 32GB Kangru SS3 - this is an expensive drive with a write protect switch
  • 64GB Lexar S25 - mid-range, but NO write protect switch

I have a script just hammering away at these drives and we’ll see how long they each take to fail. Hope to report back soon… but not too soon! :slight_smile:

1 Like


The write protect switch is a very valuable feature.

Thanks for your work on this. I was becoming skeptical about the RACHEL USB platform, but I just got strong feedback from the field on how helpful the write protect devices were for distributing material to school and teacher laptops, which are often used with a projector.

The write protect feature is essential. So essential, that my contact said that if he could raise funding and distribute a bunch of these he would use Super Glue to lock the write protect slide so as not to risk spreading viruses. Of course, he and I could make our own USB drives, but we think it is really helpful to make these available to new users of RACHEL who shop for RACHEL online. When people need an unprotected USB drive, they can almost always find one.

3.0 will also be very nice. An alternative could be a script to use some utility such as Terracopy, but that is just a suggestion.

Keep up the good work. Ed

Thanks for the feedback - agreed; I wouldn’t even bother trying to work with a non-write-protected USB in the field. Viruses are absolutely everywhere, in my experience.

I have a scripted USB build now, with a verification stage. However, after significant testing it seems the inexpensive Netac USB drives are just not very reliable. I don’t think it’s appropriate to sell them given the failure rate we’ve seen so far.

The Kanguru works well… but they are very expensive. I contacted them directly and it appears even buying in bulk we would have to bump our USB price up to $45 or so to make it worthwhile. I doubt that makes sense for many users :confused:

I would vote for putting it back in our store even at a higher price. We are helping people with two things, a write protected USB drive and a nicely set up selection from RACHEL. I hope the prices will come down over time.

Let me know if you are going through Cape Town and have a morning or afternoon free.

You might consider using SD cards in USB “Holders”. That would give two advantages: SD cards are generally more readily available in larger capacities, and they usually have their own Write Protect tab, which then is mostly hidden when inserted in the USB holder, reducing risk or unintentional switching to unprotect mode.

Hi Jonathan,

Thank you for your USB testing!

I think the RACHEL-USB is a key part of the RACHEL product line because:

  • very small schools don’t need to scale to 50 simultaneous users
  • with larger schools that only have a few laptops its more cost-effective to simply copy RACHEL to the laptops
  • schools where the laptops that are there are owned by the teachers-- the teachers want to take RACHEL home and review it there
  • with deployments of a projector and a laptop its better to have RACHEL locally deployed on the laptop - more cost effective, less complex than wifi, more reliable than wifi
  • school rooms where I was deploying RACHEL had concrete walls and were spread out-- meaning wifi is not a good answer
  • the RACHEL-USB product is a good “hook” to get teachers interested in RACHEL and advocating for more widespread use of RACHEL in their school, i.e. a RACHEL-Plus model

I’ve had some good success distributing RACHEL-USB via the write-protected Netac USBs. I have seen reviews indicating the poor reliability of the Netac USBs though.

Some questions on your USB testing with respect to the less expensive Netac USBs.

  • Are you seeing failures on reads? Writes? Both? Can you provide some detail on how they are failing?
  • Do the failures occur in the first n tests? E.g. if I test a given USB with 20 reads do I then can I predict its good for 100 reads?
  • Is there some sort of pattern/indication in the testing failures that would allow us to test a given USB before sending it out to the field. I.e. if it fails return it to the vendor and if it succeeds then send it to the field.

Thanks, AJ

Totally agreed on the usefulness of a USB / local install option. It was my primary means of distributing RACHEL in the field for years and I still do it quite often. I would really love to see this work.

To answer your questions:

  • I have had drives fail during reading and others during writing. The failure is usually complete: the drive becomes unrecognized and can’t be repartitioned or reformatted. A few times we’ve seen devices that can be reformatted after a failure, but then fail on subsequent imaging with a write failure.

  • The drives fail with unpredictable timing - sometimes right away, sometimes after days of usage. I was hoping it was just an early-failure issue that we could weed out, but I’ve seen well tested units still fail after a few days of use. Recently I set up three devices to continuously read for a several days. One failed during that time, two survived for 72 hours, and then one of those failed after being used to install on five laptops.

  • Taking the above into account, I’d say I haven’t been able to identify a reliable pattern to the failure, but it’s certainly high enough, even after rigorous testing, to be something we can’t in good conscience sell any more.

We’ll see how the higher-end drives do…

Hi our organization had some RACHEL USBs we used to use them to install the content onto reimaged PCs that would be donated to low income residents who didn’t have computers. Overtime the USB sticks became corrupted they were sent back for credit from what I’m told. This was before my time here at the organization. For a short time we were able to get Rachel content off one of our machines onto some USBs of our own. The problem is our current copy of Rachel is about 22 gb of content. The originals we 32gb zipped.

I am looking for something similar to these original USBs that can be copied onto PCs for the people we want to help in our community. If there is an idea for something else we can possibly do I am hoping for some newer solutions. If there is a place to get the same content from the original usbs or something similar that would be great.

Here it seems products are more local based network access it is great for classrooms. The PCs we referb, reimage and donate are earned by low income residents in our city. They attend pc classes for a few months and we bring them these new devices to give them tools for opportunities to rise out of poverty. RACHEL was installed on these devices so the people using the device would have access to content even if the internet was not available. I see there is some content available for download it seems like it is individual segments. If this is the only way it would be time consuming to download. It is ok if that is my only option. I’m hoping for something similar to the original USB content though. If anyone has ideas im open for those as well. one question i Have is about Rachel pi. Would i be able to put the content i want onto a Rachel Pi device and download to individual machines? Or do computers only have access to the content when connected to Rachel Pi device?

One idea I was thinking was the content we want on a network device/server that can be downloaded from the device onto our reimaged computers. This way we dont need to worry about USBs becoming corrupt overtime. USBs tend to just become corrupt overtime the more they get used. I hope this wasn’t too painful to read. I wanted to explain the current situation my colleagues and I are in and what our intentions are using a valuable tool like RACHEL.

1 Like

Thanks for reaching out, you can still download the USB here:

I do think the original was also 22GB of content, it just came ready for a 32GB usb stick.