SDCARD data corruption warning

[AliHaeri]

Hi

We use Jetson TX2 in our embedded system.
On our custom designed carrier board, we have a SD Card socket to have more storage.

When the system is powered off via normal shutdown (sudo shutdown now), there is no problem.

But, when the system experiences an instantaneous power loss ( which is unavoidable in our application), there is a warning in the kernel messages:

[   13.847290] FAT-fs (mmcblk2p1): Volume was not properly unmounted. Some data may be corrupt. Please run fsck.

I found a way to eliminate this warning, by running fsck and then deleting the “Dirty bit”. But this is not a solution to a problem which I think may eventually lead to corruption of the important data stored on SD Card.

I have two questions:

1- May this instantaneous power loss actually lead to corruption of the data stored on SD Card?

2- I know Jetson TX2 does an immediate controlled shutdown (~20ms) in the case of power loss, by using the power bad signal provide by DISCHARGE circuit on the carrier board. We have that circuit on our carrier board and have verified its functionality.
May be the problem somehow related to this?

Thanks.

[DaneLLL]

Hi,
It is possible unexpected poweroff triggers data corruption. Generally we would unmount the storage before poweroff. Without this step, it may trigger certain error.

[AliHaeri]

Hi

Thanks for your reply.

Is it possible to unmount the SD Card immediately after unexpected power off?

Another question : May be the internal Jetson 32GB storage (eMMC) corrupted by this unexpected power off?

Thanks.

[AliHaeri]

Hi.

I am awaiting for a recommendation and help…

Thanks.

[DaneLLL]

Hi,
It may not be possible to gracefully handle it in unexpected power off. Would suggest add check and recover the error status in booting.