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Re: How much time is needed to snyc?




gschallert@xxxxxxx.com said:
>  I am going to create a 4meg ram disk for the data that will change
> very frequently ( it is rare, but not unheard of, for us to do 5000
> small changes to a file in a day ).  I would like this data to survive
> a power down, but don't want to write to flash thousands of times.  I
> thought the best way to do this would be a ramdisk. 

Note that with JFFS those small changes are incremental. You don't have to 
erase and rewrite a block, just append a node saying "These bytes changed". 
So it's not necessarily _too_ inefficient.

Caching the whole file and later writing it all to JFFS, with the current
implementation, would write the whole 4MiB even when not much has changed.

You could do better than that by dealing with a flash device directly and
erasing/rewriting only those blocks which have changed. But then you run the
risk of permanently erasing data if you actually lose power (or crash)
during a sync.

--
dwmw2



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