Index: head/stand/libsa/zfs/zfs.c
===================================================================
--- head/stand/libsa/zfs/zfs.c
+++ head/stand/libsa/zfs/zfs.c
@@ -33,15 +33,16 @@
  *	Stand-alone file reading package.
  */
 
+#include <stand.h>
 #include <sys/disk.h>
 #include <sys/param.h>
 #include <sys/time.h>
 #include <sys/queue.h>
+#include <disk.h>
 #include <part.h>
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>
-#include <stand.h>
 #include <bootstrap.h>
 
 #include "libzfs.h"
@@ -517,6 +518,7 @@
 int
 zfs_probe_dev(const char *devname, uint64_t *pool_guid)
 {
+	struct disk_devdesc *dev;
 	struct ptable *table;
 	struct zfs_probe_args pa;
 	uint64_t mediasz;
@@ -532,6 +534,17 @@
 	 * disks and some systems will misreport the disk sizes and will
 	 * hang while accessing the disk.
 	 */
+	if (archsw.arch_getdev((void **)&dev, devname, NULL) == 0) {
+		int partition = dev->d_partition;
+		int slice = dev->d_slice;
+
+		free(dev);
+		if (partition != -1 && slice != -1) {
+			ret = zfs_probe(pa.fd, pool_guid);
+			if (ret == 0)
+				return (0);
+		}
+	}
 
 	/* Probe each partition */
 	ret = ioctl(pa.fd, DIOCGMEDIASIZE, &mediasz);