[meta-freescale] ext2 vs ext3/4 over eMMC

[Marc Ferland]

On Tue, Jun 26, 2018 at 6:27 AM, Mauro Ziliani <mauro at faresoftware.it> wrote:
> Hi all.
>
> I working on imx6dlsabresd clone board equiped with eMMC micron (4GB).
>
> I try some boards with my final application. All boards are the equiped with
> same hardware (I hope).
>
>
> Some board with ext2 kernel tells
>
>
> EXT2-fs (mmblk2p2): error: ext2_lookup: delete inode referenced: 138049
>
> EXT2-fs (mmblk2p2): error: ext2_lookup: delete inode referenced: 138050
>
> and the file behind the inode gives Input/Output error.
>
>
> If I format the mmcblk2p2 with ext3 or better with ext4 the lookup error no
> longer occurs (as I can see from some test)
>
>
> Where is the problem?
>
> Is it an hardware problem, that is solved by the journaling of ext3/4=?
>
> Or ext2 has some kind of "misunderstaing" with eMMC?

Typically ext3 or ext4 will help you recover from system crashes and
power failures because they use a journal to keep track of changes not
yet committed to the media . Ext2 does not have that capacity.

It is not a hardware issue.

Nice review of filesystems wrt embedded systems:

https://elinux.org/images/archive/0/02/20150326011053%21Filesystem_Considerations_for_Embedded_Devices.pdf

Marc