jffs2 help

hi all,

i have a specific issue that seems realted to jffs2,
i tried to subscribe to jffs2-dev list but seems no more existing.

Just a suggestion, is there some jffs2 list/support still alive from Axis ? Is jffs2 the right way to go to store some non volatile data to a nor flash or is it better i move directly to UBIFS ?

thanks,
angelo

Axis pioneered the development of the original JFFS, but did not drive the development of JFFS2, and so there is no active support from Axis for either file system, and hasn't been for many years.

The right place to ask for JFFS2 help is on the linux-mtd mailing list, i.e. right here.

I leave that one up to others, but basically I think the take is this:

ubifs resides on top of UBI, which works with both NOR and NAND flashes, but several of the features that UBI brings (transparent bad block management and bit scrubbing) are primarily intended to cover up the deficiencies of NAND flash. On the other hand, the whole logical volume concept which is also a feature of UBI is useful for any type of flash.

ubifs seems to mount faster, I think because it doesn't scan the whole flash at mount time like JFFS2 does, although I seem to recall there's an option to store summary info on the flash rather than built it at mount time. Not to sure exactly the various permutations here though.

In more general terms, jffs2 is pretty stable, on the other hand, there's not much maintentence going on either; the main work goes into UBI and ubifs, so the that's where the real development is.

/Ricard

Ricard Wolf Wanderlöf                           ricardw(at)axis.com
Axis Communications AB, Lund, Sweden            www.axis.com
Phone +46 46 272 2016                           Fax +46 46 13 61 30

Angelo,
I suggest you to start using ubi.
Take a look to the following Free-electrons document to see a benchmark of flash file systems

http://free-electrons.com/doc/flash-filesystems.pdf

BTW on Free electron site you can find a lot of helpful documentation, take a look on it.

Bye Daniele

-----Messaggio originale-----
Da: [email protected] [mailto:[email protected]] Per conto di angelo
Inviato: martedì 3 maggio 2011 18.32
A: [email protected]
Oggetto: jffs2 help

hi all,

i have a specific issue that seems realted to jffs2,
i tried to subscribe to jffs2-dev list but seems no more existing.

Just a suggestion, is there some jffs2 list/support still alive from Axis ? Is jffs2 the right way to go to store some non volatile data to a nor flash or is it better i move directly to UBIFS ?

thanks,
angelo

______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

Hi Daniele and Ricard,

thanks both for the help.

The free-electrons site is really a wonderful help. I couldn't find it out through googling "mtd jffs2" still.

Anyway, still, following strictly the site help, i can eraseall, mount jffs2, write some files, unmount, but at the next mount nothing is still there. Option -o sync doesn't help also.
Writing files, i still get errors like

Node totlen on flash (0xffffffff) != totlen from node (0x0000000c)

I probably will move to UBIFS, but before i would like to understand why jffs2, that should be reliable in anyway, is failing on my flash.

Regards,
angelo

<http://www.sysam.it>

I agree, if you cannot get jffs2 to work, there must be something that's not configured properly.

Reliability is one thing, but short term for tests like this any problems you encounter are not due to failing bits in the flash etc but some sort of misconfiguration or bug.

/Ricard

Ricard Wolf Wanderlöf                           ricardw(at)axis.com
Axis Communications AB, Lund, Sweden            www.axis.com
Phone +46 46 272 2016                           Fax +46 46 13 61 30