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Hospital – Fake Flash Devices – Fix Fake Flash

Linux H2testw Alternative Program Called F3 By Michel Machado

Posted by inspectortech on August 20, 2010

F3 by Michel Machado is an open source Linux software to test flash memory capacity. H2testw does nor run in Linux. There are two programmes, one to read and one to write files to the item being tested.

If you are a Linux user and need to test flash memory cards, usb flash drives and mp players. please try out F3.

Michel Machado:

F3 is an open-source, command-line implementation of my understanding of how H2testw works. I’ve only tested it on my Ubuntu / Linux desktop, but it should compile and work on other platforms with almost no changes. I’ve only tested USB sticks that I have, but F3 should work on wherever media that you have access to, including mp3 players, hard drivers, and RAM drivers.

F3 is composed of two binaries: f3write, and f3read. f3write fills a file system up with 1GB files named NNNN.fff, where N is a number. Whereas, f3read validates those files. If the content of all NNNN.fff files is valid, the memory is fine. The last file may be less than 1GB since f3write takes all available space for data.

Please visit – F3 – an alternative to h2testw. Make sure to read Michel’s page and instructions.

Please leave feedback on the results of F3 here.

Currently F3 is in pilot and we would like to see how it performs for testing flash memory on the Linux platform. Linux users need a flash memory testing software, your input is needed.


15 Responses to “Linux H2testw Alternative Program Called F3 By Michel Machado”

  1. david said


    I recently used this software to check a fake memory card bought from ebay. I’m pleased to say the software works well in identifying the true capacity of memory cards.

    I first tested with my fake card and then checked with a non-fake memory stick, and it worked fine in both cases (sadly my ebay card was a fake though :/).

    Michel’s instructions are easy to read too, assuming you know how to use a terminal (but most linux users would be fine with this I’m assuming).

    Thanks for providing this software, it saved me a lot of confusion about where my files were disappearing to: it turns out they were just disappearing!

  2. Art G said

    I just F3 to test a 2 gig mini-card and it worked very nicely. It was a reputable brand bought at a nationally known store so I was pretty sure it was ok, but now I have some assurance that it is what it says it is.

  3. SebaX75 said

    Worked fine to test a fake memory after it had fixed.

  4. Andre said

    I used F3 to test an SDHC card from ebay, and verified it was indeed a fake. I tried to also run H2testw on a Windows machine to compare the results, but by that time, the memory card had stopped working completely. Thank you for this program – it was nice to have a Linux alternative. And it was epsecially nice to be able to examine the source code.

  5. Wade Hilts said

    Hey, this program seems excellent, but it doesn’t work on mac computers. Does anyone know if there is any alternative program that can work on Mac’s? I’m pretty sure I got a faulty 32G SD card that really only holds about 14G

  6. CoolStar Organization said

    If you guys want, I can create a wrapper program around F3 and call it gF3. It will be the exact same, except using the GTK Library for a GUI. I’ll also open source it so you guys can be sure that the program is real. I don’t want to make a fake program here.

  7. Kris said

    Nice! But please educate us how is this different from “dosfsck -vtr …” ; also, how to check if i got version 2 or 3 etc? is there a man page or such for it once i “make” it? (newbie here). thanks again.

    • Hi Kris,

      dosfsck(8) makes two assumptions that F3 does not:
      1. One needs right access to the device being tested, not the file system in it.
      2. Hardware may fail, but it won’t lie.

      The first assumption implies that you likely need root’s rights to run dosfsck what’s just a small incovenience for simple uses. The second assumption is troublesome because a fake card may be able to persuade dosfsck to report it’s fine, or not report the whole problem, or give users that the memory card was fixed when it wasn’t.

      I singled dosfsck out because you asked about it, but those two assumptions are true for fsck softwares for other file system formats and badblocks(8) as well.

  8. Mauro said

    i’m sorry for bothering you with such petty problems, but i am a linux ultranoob. i was able (searching through google) to compile the program. but when i try to execute, this message appears:
    ./f3write /media/MAURO SD/
    Usage: f3write
    So i was wondering if anyone could help me to run this program, thank you

  9. Mauro said

    I tried running the program. I could compile it, however when i use command .f3write /media/MAURO SD ; following appears: Usage: f3write

    I am a linux noob, so if it is possible for someone to help me.
    Thank you

    • david said

      Hi Mauro,

      It looks like you are putting 2 arguments to the command, when a quick look at the F3write page shows the command only with one. this is because of the space you have between MAURO and SD.

      Your command should look like this:
      .f3write /media/MAURO\ SD
      if this space really exists in your path. give this a try.

      • david said

        Of course your command should be
        ./f3write /media/MAURO\ SD/

        Don’t forget the forward slash in ./f3write (it was my fault for cut and pasting)

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