Testing SD cards for fake capacity with f3 under WSL2
How to mount a Windows drive letter (an SD card) in WSL2 with drvfs and run f3write/f3read on it to detect counterfeit, under-capacity cards.
Tested onWindows 10; WSL2 (Ubuntu); f3 7.x
Symptoms #
You want to check whether an SD card really has the capacity it claims (fakes report a large size but silently lose data past the real capacity), and the only Linux you have is WSL2.
Fix #
Mount the card's drive letter (here E:) with drvfs, then run
f3:
bashsudo apt install f3
sudo mkdir -p /mnt/e
sudo mount -t drvfs E: /mnt/e
f3write /mnt/e
f3read /mnt/e
f3write fills the free space with test files; f3read reads them back and reports corrupt
or overwritten sectors. A genuine card shows no losses. See the
LinuxReviews guide
for more background.
Cause #
Not a bug, just the missing step: WSL2 does not auto-mount removable drives, so you have to
mount the letter yourself with -t drvfs.