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Comment by rahimnathwani | Hacker News Reader

This advice should go without saying:

"Re-format the random SD cards you get from Amazon specifically on the device you're gonna use them."

Do this also for portable hard drives.

Since it comes up so often now, reformat the drive and then do what to verify that it's a legit drive, and not one that advertises as being larger than it actually is?

Put a bunch of large media files on it and verify that they still play properly?

I always use this tool https://github.com/AltraMayor/f3

It fills the entire device with data and then tries to read it all back. It can tell you how many bytes were successfully read, how many were corrupted and how many were written over by other writes.

Even on cards I know are real I still run the test because I have had a card that had a few bytes that got corrupted which caused loads of issues with my rpi.

I usually use f3probe, which IIRC uses some heuristics and trades of accuracy for speed, i.e. it doesn't write to the entire drive.

The docs are lower down the page from the main f3 utils:

https://fight-flash-fraud.readthedocs.io/en/latest/usage.htm...

The test time can be pretty insane on the high capacity cards. I remember it took about 4 hours to test a 256gb card but I find its worth it to check the card just once since it saves a lot of pain later when you find one tiny part of the card is failing.

I used h2testw on Windows to do this. It writes a 1-GB files with a special pattern on the disk until it is full (or however many GB you specified before starting it). It then tries to read them all back to see if they have been written correctly.

Any storage device I buy gets at least a full pass of read/write testing, any errors means it's being returned as not fit for purpose. SSDs and HDDs get 8 full passes.

Why 8, and not 4 or 7 or 16?

with a QLC drive, like the 660p, 8 cycles is 4% of your total drive life...

To be fair, he did test the storage device:

"I did a local recording right there and played it back. Sounds good. I played it back locally on the Zoom and I could hear the recording from the Zoom's local speaker"

That test doesn't really give you any more information than noticing that you didn't get a "card not found" error. A full-capacity write and read verification is a test that's actually informed by the possible failure modes that wouldn't be immediately apparent from ordinary usage.

If you're worried enough to take the deliberate step of manually testing your storage device, you should at least make sure it's a useful test that tells you something you don't already know.

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