Two ubifs errors

[Smitha Rathnam]

Hi All,

I posted a similar problem earlier. This time my question is slightly different.
First: We have a system that uses the linux 2.6 kernel, ubifs. We use
a micron nand device.
The system uses two partitions, one for the ubi rootfs and the other
for the ubi logfs.
We found that in the last few months, the system has been failing on
the logfs. And we lose data. The error seen is "UBIFS error. LEB xx
scanning failed."

We got around this error by reinstalling (which essentially formats
the partitions) software. But we lost the data.

Second: The question was how to reproduce the issue. After looking
through forums, I found that it is mostly related to losing power when
writing to the nand.
So we setup a test station with three systems running the same
software version writing lot of data to the nand and continuously
powercycling the system. After running the tests for two days, we
found one system had broken down after 2000 power cycles. While the
others had not. After restarting the test, we found that another
system had broken down with the same error after two days but after
300 power cycles. This time it failed while scanning LEB 2733.

One of the systems shows the bad block error which seems to show up in
the ubi rootfs. This does not affect the nand fs.

My worry and question is: Why are all systems not failing after two
days? One system seems to be more succeptible than others. What could
be the explanation for that?
I have some logs. Please have a look and advise.
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