How to Use the Command 'f3read' (with Examples)

The f3read command is part of the F3 software suite designed to test the true capacity of storage drives, particularly flash drives. It is primarily used to identify counterfeit drives that falsely advertise larger storage capacities than they actually possess. By validating .h2w files, f3read helps reveal the real usable space on a drive. Other related commands in the suite include f3write, f3probe, and f3fix, all of which serve to diagnose and remedy issues with storage devices. More information about the F3 suite can be found at https://oss.digirati.com.br/f3/ .

Validate a device by checking the files in a given directory

Code:

f3read path/to/mount_point

Motivation:

The motivation behind using the f3read command in this manner is the need to ensure that a storage device, particularly a newly purchased flash drive or memory card, truly has the capacity it claims to offer. Counterfeit storage devices can trick users into believing they have more storage capacity by manipulating how the drive reports itself to the operating system. However, when actual data is written to such devices, it may become corrupted or lost if the drive is pushed beyond its actual capacity. By validating the files within a specified directory on the drive, f3read can alert the user to potential discrepancies between reported and actual storage capacities, helping to avoid data loss.

Explanation:

• f3read: This is the main command used to start the reading process of the .h2w files previously written by another command in the F3 suite, typically f3write.
• path/to/mount_point: This argument specifies the directory path where the drive is mounted. It is the location where the drive’s contents will be read and validated. This is where the .h2w files created by f3write reside, allowing f3read to read and verify them against the expected data patterns, ensuring the drive’s claimed capacity is genuine.

Example Output:

Free space: 0.00 Byte
H2testw version 1.3
Warning: Only 16780 of 16781 MByte tested.
The media is likely to be defective.
16770 MByte OK (34355261 sectors)
10 MByte DATA LOST (19839 sectors)
Details:16 KByte overwritten (32 sectors)
0 KByte slightly changed (< 8 bit/sector, 0 sectors)
0 KByte corrupted (0 sectors)
8 MByte aliased memory (16384 sectors)
First error at offset: 0x0000000082e00000
Expected: 0x0000000082e00000
Found: 0x0000000000000000
H2testw version 1.3
writing: finished without errors
reading and comparing: May  2 23:09:45 2023
real    2m0.779s
user    0m0.122s
sys     1m8.549s

In this example output, the test indicated that a portion of the drive did not perform correctly under stress conditions, revealing that part of the claimed memory is not actually usable. It accurately measures how much data can safely be stored without risking corruption or loss. This output shows both the total space that is usable, any data that was lost, and details of any discrepancies noted during the read operation.

Conclusion:

The f3read command is an essential tool in verifying the legitimacy of a storage device’s stated capacity. It is particularly useful for identifying counterfeit or deceptive storage devices that could lead to data loss due to incorrect capacity reporting. By using f3read, users are empowered to protect their data by ensuring that their storage devices are both authentic and suitable for their needs. Understanding how to deploy this command effectively can lead to more informed purchases and safer data storage practices.