A couple of weeks ago I fixed a nasty bug in this function in OpenZFS: /* * This code converts an asize into the largest psize that can safely be written * to an allocation of that size for this vdev. * * Note that this function will not take into account the effect of gang * headers, which also modify the ASIZE of the DVAs. It is purely a reverse of * the psize_to_asize function. */ static uint64_t vdev_raidz_asize_to_psize(vdev_t *vd, uint64_t asize, uint64_t txg) { vdev_raidz_t *vdrz = vd->vd...