11056 vdev_disk_io_start will panic the system if ldi_strategy returns an error.
illumos/illumos-gate@fa88c70fa54c01be933cc49fd271e5c4468f7eb8
https://github.com/illumos/illumos-gate/commit/fa88c70fa54c01be933cc49fd271e5c4468f7eb8
https://www.illumos.org/issues/11056
Author: Jerry Jelinek <jerry.jelinek@joyent.com>