Hi Xiao,
That particular array is super1.2. The block trace was captured on
the disk underlying the partition device on which the md array member
resides, not on the partition device itself. The partition starts
2048 sectors into the disk (1MB). So the 2048 sectors offset to the
beginning of the partition, plus the 8 sector superblock offset for
super1.2 ends up at 2056.
Sorry for the confusion there.
Regards,
--Chris