f3read(1)

f3read1

Test real flash memory capacity

Usage

f3write [--start-at=NUM] [--end-at=NUM] <PATH>

f3read [--start-at=NUM] [--end-at=NUM] <PATH>

Overview

F3 (Fight Flash Fraud or Fight Fake Flash) tests the full capacity of a flash card (flash drive, flash disk, pendrive). It writes to the card and then checks if can read it. It will assure you haven't been sold a card with a smaller capacity than stated.

When writing to flash drive, f3write fills the filesystem with 1GB files named N.h2w, where N is a number (i.e. /[0-9]+/).

WARNING: all data on the tested disk might be lost!

Options

--start-at=NUM

Initial number of file names. Default value is 1.

--end-at=NUM

Final number of file names. Default value is "infinity".

Examples

To write over a flash drive mounted at /media/TEST:

      $ f3write /media/TEST

To read this flash drive:

      $ f3read /media/TEST

Releases

6 releases since Debian 8 (Jessie); the text changed 4 times.

  1. 8
  2. 9
  3. 10
  4. 11–12
  5. 13

Author

F3 was written by Michel Machado <[email protected]>. This manual page was first written by Joao Eriberto Mota Filho <[email protected]>.

From f3 9.0-1 in Debian 13 (Trixie). Parsed by carta from the page's man source.