On 2010-05-31, Neil Bothwick <n...@digimed.co.uk> wrote:
> On Sun, 30 May 2010 14:20:36 +0000 (UTC), Grant Edwards wrote:
>
>> > You're assuming that each backup only writes once, which is far from
>> > true. If you mount a drive with the sync option, the FAT is updated
>> > for every block you write, so even a single file can cause thousands
>> > of writes to the same location.  
>> 
>> And you're assuming that the flash controller chip in the USB drive
>> doesn't do wear-leavelling.
>
> Even with wear levelling, writing in sync mode still does thousands of
> writes. They may be more spread out, but there are still a lot more than
> one per day and the previous assumptions are still false.

Agreed.  Sync writes will definitely wear out flash sooner, but it's
not as bad as one might think since flash controller chips _generally_
do wear levelling and may even do bad-block management that will swap
in spare blocks when wornw blocks start to go bad.  Of couse, none of
the USB thumb-drive vendors will ever spec any of that, so you have no
way of actually knowing.

-- 
Grant






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