On 13/01/2020 17:31, Song Liu wrote:

quoted

Song, Neil,

Just a guess as to what went wrong, but the array event count does not
match the disk counts. Iirc this is one of the events that cause an

Which mismatch do you mean?

quoted

assemble to stop. Is it possible that a crash at the wrong moment could
interrupt an update and trigger this problem?

It looks like sdc1 failed first. Then sdd1 and sdf1 got events for sdc1 failed.
Based on super block on sdd1 and sdf1, we already have two failed drive,
so assemble stopped.

Does this answer the question?

Sorry yes it does. My fault for mis-reading the logs the OP sent.

Cheers.,
Wol