Re: need arguments to use JFFS2

Charles Manning
2002-12-07T08:09:27Z

It is virtually impossible to make any firm statements without understanding
your needs a bit better.

A few others have already covered cramfs and JFFSx. I can tell you a bit
about YAFFS.

YAFFS only works with NAND flash. YAFFS does not provide compression (like
JFFS does). YAFFS is faster than JFFS2 in most situations and uses less RAM.
Mileage will vary though. Compression is not necessarily a huge advantage for
JFFSx. Some people loop-mount a cramfs image stored on YAFFS to get the
benefits of compression as well as the faster speed for other files.

If you have NAND, then most likely YAFFS will serve you better for larger
flash arrays (say 16MB and bigger) and JFFS2 for smaller arrays.

YAFFS will do nothing for you if you only have NOR flash.

If you're designing a new board then consider including NAND flash for
storage (rather than NOR). NAND is cheaper, smaller (physically), bigger (in
bytes) and faster. You can then use YAFFS or JFFS2 (even both - by
partitioning the device).

-- Charles