On Fri, Oct 05, 2012 at 05:43:46AM +0200, Maxim Kammerer wrote: > Did anyone try this with devices that are supposed to be resistant to > file shredding due to wear leveling? I tried the following on two USB
Wear levelling is a function of newer devices (your old USB flash sticks are unlikely to have it, but your new SSD definitely has) and it hides damaged blocks transparently by using the overprovisioned flash block pool (its size depending on on whether consumder or enterprise drive, the latter having more overprovisioning). It might be possible to access the damaged blocks via a debug function, or by flashing the drive with custom firmware. > keys, one ~12 years old, another ~6 years old, both formatted as > FAT32: > > echo test_string_123 > x > for i in $(seq 20); do cat x x > x1; mv x1 x; done > cp x /media/... && sync > shred -u /media/... && sync > cp /dev/sd... image > LC_ALL=C grep -wc test_string_123 image > > The result was 0 in both cases. -- Unsubscribe, change to digest, or change password at: https://mailman.stanford.edu/mailman/listinfo/liberationtech
