The drive was hollow in the middle.

[walthouser]

I ran validrive on a no-name "8GB" USB drive that had only 4KB valid. It reported valid regions at the beginning and end but missing regions spread throughout the drive.

test date and time 10/23/2023 at 11:18 AM
declared drive size 8,053,063,680 (8.05GB)
validated drive size 4,096 (4.10KB)
highest valid region 8,053,063,680 (8.05GB)
hub or drive vendor generic
hub or drive product flash_disk
serial number 7a0d99f9

Maybe we should start posting these findings as user reviews on Amazon and other vendors,
Thanks, Steve, for this valuable tool.

 

[Steve]

Wow! THAT is a weird one!

 

[walthouser]

I guess the maker intended to avoid detection by a test that looked only at the beginning and the end of the drive. I assume that's why you wrote validrive to test the entire drive?

 

[SeanBZA]

Yes 4k says the flash is failed, probably the die has massive defects, or is cracked. But can be a fake, where the firmware uses the firmware area to return a valid FAT partition and then has 4k as the start of the FAT, and the final 4k block as the end of drive, which is all the quick format looks for. Only needs 8k of working flash, as most OS systems will not actually verify the second copy of the FAT in any operation, just write to update it, using the first copy info, and only aborting if there is a write error returned by the drive.