On 12/05/2017 10:55 AM, 002@tut.by wrote:

A well known reason for this behavior are bad blocks in device's BBL,
which you happen to have:

[trim /]

This feature generally shouldn't be used, because its implementation
is unfinished. Empty BBL's can be removed from every device by giving
"--update=no-bbl" option to mdadm on assemble, but before that you
must manually regenerate content for each block in BBL's and then
manually zero the lists in superblocks.

I endorse this opinion.  The BBL should never have been merged as-is.
Without a block reallocation system like a real hard drive, a BBL entry
simple drops redundancy on the block in question without any other
corrective action.

Completely, utterly, brain-dead.

At the very least, it should not be enabled by default on new arrays.

Phil