What is ZFS block size ?
The size of a block is described by three different fields in the block pointer; psize, lsize, and asize. * lsize: Logical size. The size of the data without compression, raidz or gang overhead. * psize: physical size of the block on disk after compression * asize: allocated size, total size of all blocks allocated to hold this data including any gang headers or raid-Z parity information All sizes are stored as the number of 512 byte sectors (minus one) needed to represent the size of this block.