P Witte wrote: > Nasta writes: > >>>I know youve sort of answered this before, but the one thing that gives >>>me >>>cause for concern is the long-term reliablity of CF media. And how are we >>>going to notice - apart from in the most unpleasant way - that its >>>natural life is reaching its close?
>>> >>CF cards use flash memory chips which can take at least 1 million writes >>to >>the same location - and the internal controller does not let the bytes be >>written to the same place if it can avoid it. Instead, the writes are >>'staggered' - a sector that is overwritten is actually declared empty and >>another is written instead, than that one is 'soft-remapped' to be at the >>same space as it's previous 'version'. Previously written sectors are only >>rewritten if it cannot be avoided due to running out of space. All of this >>is actually quite easy to do on a block oriented device, unlike one with >>purely random writes. Stupid question: how is the "soft-remapping" stored? I only ask as it seems obvious that this has to be constantly re-written each time a sector's physical location changes - or am I thinking too much in terms of disk allocation maps
