I formatted my two mirrored drives only with the casesensitivity and ashift parameters. I noticed yesterday that the block size is set to 128 KB in the "zfs get all" listing.
Does this mean that every time a change is needed, a new 128 KB block will be written at the end? This is not very efficient given the usual size of files, lower than 128 KB.
The choice comes from the need of storing checksums? or for performances?