.... > > The location of block allocation bitmaps never gets changed, so this > > sort of thing only happens due to hardware-induced corruption. > > Well, unless e.g. some modified sectors start being flushed to random > wrong offsets, like in [1] above, or something similar. Or cutting the power in the middle of SSD 'wear levelling'. I've seen a completely trashed disk (sectors in completely the wrong places) after an unexpected power cut. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)