Question about SMR drives. From my understanding, essentially at the low level they have to modify data in much larger block sizes -- so if you are modifying a

Question about SMR drives. From my understanding, essentially at the low level they have to modify data in much larger block sizes -- so if you are modifying a small amount of data, a block has to be read in, modified, then written out. Unless the block is known to contain no data after the point where the write occurs (such as sequential writes). What is the size of these blocks? And if the problems occur during raid rebuild, aren't the rebuilds writing data sequentially?