Pass info to zpool cmd whether devices are solid state, or rotational.

include/sys/fs/zfs.h

@@ -729,6 +729,13 @@ typedef enum vdev_aux {
 	VDEV_AUX_SPLIT_POOL	/* vdev was split off into another pool	*/
 } vdev_aux_t;
 
+typedef enum vdev_nonrotational_info {
+	VDEV_NONROTATIONAL_UNKNOWN = 0,	/* not set yet			*/
+	VDEV_NONROTATIONAL_YES,		/* device is solid state	*/
+	VDEV_NONROTATIONAL_MIXED,	/* device has both kinds	*/
+	VDEV_NONROTATIONAL_NO		/* device is not solid state	*/
+} vdev_nonrotational_info_t;
+
 /*
  * pool state.  The following states are written to disk as part of the normal
  * SPA lifecycle: ACTIVE, EXPORTED, DESTROYED, SPARE, L2CACHE.  The remaining
@@ -818,6 +825,7 @@ typedef struct vdev_stat {
 	hrtime_t	vs_timestamp;		/* time since vdev load	*/
 	uint64_t	vs_state;		/* vdev state		*/
 	uint64_t	vs_aux;			/* see vdev_aux_t	*/
+	uint64_t	vs_nonrotational;	/* nonrotational	*/
 	uint64_t	vs_alloc;		/* space allocated	*/
 	uint64_t	vs_space;		/* total capacity	*/
 	uint64_t	vs_dspace;		/* deflated capacity	*/

module/zfs/vdev.c

@@ -2920,6 +2920,16 @@ vdev_get_stats_ex(vdev_t *vd, vdev_stat_t *vs, vdev_stat_ex_t *vsx)
 		    !vd->vdev_ishole) {
 			vs->vs_fragmentation = vd->vdev_mg->mg_fragmentation;
 		}
+		/*
+		 * This is static information, so could be set in vd->vdev_stat
+		 * elsewhere...?
+		 */
+		if (vd->vdev_nonrot)
+			vs->vs_nonrotational = VDEV_NONROTATIONAL_YES;
+		else if (vd->vdev_nonrot_mix)
+			vs->vs_nonrotational = VDEV_NONROTATIONAL_MIXED;
+		else
+			vs->vs_nonrotational = VDEV_NONROTATIONAL_NO;
 	}
 
 	ASSERT(spa_config_held(vd->vdev_spa, SCL_ALL, RW_READER) != 0);