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RE: jffs2 flash life calculation



Lets say I do rougly 1K writes, 35 times in 10 minutes.

Lokesh

-----Original Message-----
From: Charles Manning [mailto:manningc2@xxxxxxx.nz]
Sent: Wednesday, August 20, 2003 9:19 PM
To: Lokesh Kumar; 'jffs-dev@xxxxxxx.com'
Subject: Re: jffs2 flash life calculation


On Thursday 21 August 2003 02:31, Lokesh Kumar wrote:
> We are developing a product, which requires a flash life span of 10 years.
> Specs are - 350KB data / 10 minutes, at any given time 2MB data in flash,
> NOR flash which has 100K erase cycles/ block, with 128k sector size. This
> is Intel startaflash, with JFFS2 over MTD.
>
> How do I calculate the required flash size, taking wear-leveling of JFFS2
> into account. Where can I find this information?
>

Answering questions like this is not easy. The impact will depend on various

factors such as what your writes do and how they impact the generation of 
discarded data and thus garbage collection etc.

For example, if you write 350kB as a single write() call you will generate 
far less garbage than is you do 10240 writes of 35 bytes, or worse still 
overlapping writes.

-- Charles


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