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Re: run debian off usb flash drive



On Mon, 29 Mar 2004 03:20, Goswin von Brederlow 
<brederlo@informatik.uni-tuebingen.de> wrote:
> Point is that a one byte write still needs a 128K erase. Unless some
> higher level ensures against one byte writes 250 bytes could mean 250
> erases.

The way flash works is that you can flip bits one way without any cost, but 
flipping them the other way requires an erase cycle (which wears it out).

So if you want to erase a file-system block without erasing the flash block 
(flash block being significantly larger than the FS block) then you just 
change a bit in the FS block header to indicate that it is obsolete.  The 
JFFS2 docs describe this.

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