Re: data loss on jffs2 filesystem on dataflash

Peter Menzebach
2005-09-20T13:39:01Z

Artem B. Bityutskiy wrote:
>> Artem B. Bityutskiy wrote:
>> I glanced at the manual. Uhh, DataFlash is very specific beast. It
>> suppoers page program with built-in erase command... So DataFlash
>> effectively may be considered as a block device. Then you may use any
>> FS on it providing you have wrote proper driver? Why do you need JFFS2
>> then :-) ?
I do need some wear leveling (and a filesystem which supports block
sizes of 1056 bytes ;) )

>> JFFS2 orients to "classical" flashes. They have no "write page with
>> built-in erase" operation.
>>
>> Didn't read the manual carefully, what do they refer by "Main memory
>> array"?
The main memory array is the flash itself with pages of 1056 bytes

>> BTW, having 8*1056 write buffer is not perfect ides, better make it as
>> small as possible, i.e., 1056 bytes.
At the moment, the write buffer = reported erase block size. Is this
neccessary that this is equal?

my reasons for setting erase block size to 8(16)*1056:
1. my lazyness -> I have to patch the mkfs.jff2 every time, since it
makes a guess, that -e 1056 is not a very good idea (at lest the
versions some times ago)

2. It seemed to me, that jffs2 boots faster, if the number of blocks is
smaller.

3. A guess without proof: jffs2 likes blocks which are not too small

Best regards
Peter

--
Peter Menzebach
Menzebach und Wolff IT-Consulting GbR
Phone +49 751 355 387 1