Nick Bane wrote:
>> Hello everyone,
>>
>> Question #1: I was told that UBIFS is better than Yaffs2, is that
>> true? What are pros and cons?
>> Question #2: It was said that Android 2.1 cannot use Yaffs2, is that
>> true? If so, why?

<snip>

> These figures take no account of newer yaffs2 speed improvements, no
> account of the degraded power security of cached writes and no account
> of reliability issues surrounding not verifying nand writes. Verifying
> nand writes is ok under ubifs but the header offsets must be page (not
> sub-page) aligned until sub-page verifies are fixed in mtd. Using page
> aligned headers which requires that userland ubifs utils must have
> knowledge of the underlying nand architecture - ugh.
> 
> My impression of running our applications on ubifs is that the write
> speed and boot speed (especially without a clean unmount) is faster but
> without the numbers to back it up this is only an impression. Installing
> packages using dpkg (which makes many writes/moves) also seems much
> faster. Overall reliability is far too early to judge.
> 
> If someone can tell me how to do a git checkout without using long
> unmemorable nubers I could redo this with a more modern yaffs2.

I am curious as to whether these numbers, which seem to imply UBIFS is
drastically faster than YAFFS (tar decompress 3x faster, dpkg 20% faster
etc...) might be to do with using compression. The CPUs a lot of people
are using now are pretty high end, and while NAND speed has improved, it
is probably still quicker to compress data and thus write less of it.

Has anyone ever looked at using LZO or similar compression within YAFFS
to reduce the amount of data written?

Regards,
Andre