Lenovo firmware ISO ruined my USB thumb drive - how to fix? I've never seen this kind of thing before. I have a 32GB thumb drive, which I tried to put a Lenovo BIOS/firmware updater on. It didn't work out, so now I'm trying to format it, but I can't. Mac OS tells me the target disk is too small.



The thumb drive is now named HFET36US, and is apparently mis-reporting its capacity as 17.1MB. I've already tried formatting it via Disk Utility and the command line:

diskutil eraseDisk ExFAT NewName /dev/disk5


Which just gives the error:

Unable to begin erase operation: The target disk is too small for this operation (-69771)
Ok, fixed it via:

diskutil partitionDisk /dev/disk5 1 MBR ExFAT whatever 32GB


I wasn't sure what the 'whatever' argument was supposed to be, but it worked.