[Sugar-devel] Filesystem for SD cards / USB sticks

[Jonas Smedegaard]

On Mon, Aug 31, 2009 at 09:01:31AM -0700, H. Peter Anvin wrote:
>On 08/31/2009 02:57 AM, Jonas Smedegaard wrote:
>>
>>>> I would assume that the any DOS filesystem will continouously 
>>>> rewrite to the FAT blocks.  Maybe the best choice would be ext4 
>>>> with the journal disabled?
>>> The increase of data written to the card with journalling enabled is 
>>> less than 4% for normal operations (up to 42% for very 
>>> metadata-intensive operations, but then the amount written is low in 
>>> absolute terms) according to Ted Ts'o [1] (who has quite a number of 
>>> interesting SSD-related articles in his blog). For me having a 
>>> journalling filesystem is worth a lot more than just 4% write data 
>>> increase (I even use data=journal on most systems).
>>
>> I know that article, and the reason I still recommend disabling 
>> journaling is due to that "write amplification effect" also mentioned 
>> in the article.
>>
>> So do you do not care about the write amplification effect, or so you 
>> assume that SD card and USB sticks have silently solved it similarly 
>> to the (seemingly high-end) Intel X25-M SSD?
>>
>
>Or he considers protecting the state of the filesystem to be more 
>important.

Good point!

Boils down to no simple answer for "what is *best*?", I guess. :-P


  - Jonas

-- 
* Jonas Smedegaard - idealist & Internet-arkitekt
* Tlf.: +45 40843136  Website: http://dr.jones.dk/

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