USB flash drive, bad/fake capacity

[deso]

Anyone remember a little program someone devised to mark bad sectors using a bitmap file of a specific size - the program basically copied and pasted the bitmap until the drive was full, then by looking at the drive contents you could identify the bad sectors as those where the bitmap wasn't properly copied. I've used it in the past but can't find it now. Thanks.

[ChuckFickens]

Why not just run a disk check on the drive?

Although it's not really recommended to use utilities like the one you describe or disk check too often on flash drives as they have a finite amount of times each sector can be written to and running any utility such as these will reduce the life of the drive.

[deso]

Because it's one of those hacked fake drives that says 8Gb when it's really only only 1Gb so what you suggest doesn't actually help. Thanks for replying though. As it happens I found what I was looking for yesterday, tucked away in 'my documents'. if you're interested, it identifies the bad and fake sectors by repeatedly copying a 729kb bitmap to a folder named BAD on the drive until it's full. What I ended up with was 1351 good bitmaps totaling 966Mb of space. The trick is to then delete the GOOD bitmaps and leave the partially written or unwritten ones in the folder. Now when I look at the drive properties it shows 966Mb free space (which was the 1351 good bitmaps) and 7.04Gb used, which is actually only 53 bad/unwritten bitmaps. When I use the drive in earnest I know I can only write to 966Mb, but I know it's a genuine 966Mb and I will not lose any data. It takes a few hours for the program (it's actually a simple batch file) to run, but well worth the time if your flash drives are useful to you.

[ChuckFickens]

Fair enough....

Although at less than £5 for a 8GB drive these days I'm not sure I'd be bothering trying to rescue usability from a faked drive with 1GB usable space.

[Old_Geezer]

Not an expert but I think this sort of thing doesn't work on the flash drive as it does on a magnetic disk. Dynamic mapping of "sectors" and suchlike ? Full marks if you know it works and can find such an ap (let us know) but in my experience if you get conned and can not open it up to correct it, then the bin is the best place for the drive.

[deso]

Chuck - I bought the drives a few years ago when they were considerably more expensive, I sorted a few out back then but I've recently resurrected them for a specific purpose but still had 3 or 4 not sorted so I'm just sorting them now - 1Gb is big enough for what I need so no point throwing good money after bad! (Incidentally, the bloke who sold them to me on e-bay ended up getting jailed for 18 months after a few of us got together and forced e-bay/police to act. It was a big operation he was running).
Old Geezer - I'm no expert either but the flash drives I've 'repaired' have worked very reliably (so far...)

[palbeda]

There is another simple and good option that I have not found so far and that is to define a smaller partition on the usb drive and so making the partion the same size as the actual size of the usb drive. That works fine, is easy to do and in my opinion better as just marking blocks bad, as you may loose the markings accidentally in a format. My solution is "format prove".

Sorry you had to wait two years for this answer, unfortunately fake usb drives are still being sold today...