diff --git a/include/libzfs.h b/include/libzfs.h
index 082b690e9249..e0c695043282 100644
--- a/include/libzfs.h
+++ b/include/libzfs.h
@@ -675,7 +675,10 @@ extern int zfs_nicestrtonum(libzfs_handle_t *, const char *, uint64_t *);
 /*
  * Utility functions to run an external process.
  */
-int libzfs_run_process(const char *, char **);
+#define	STDOUT_VERBOSE	0x01
+#define	STDERR_VERBOSE	0x02
+
+int libzfs_run_process(const char *, char **, int flags);
 int libzfs_load_module(const char *);
 
 /*
diff --git a/lib/libzfs/libzfs_mount.c b/lib/libzfs/libzfs_mount.c
index a1faf49d1ac7..1dc58f924a3e 100644
--- a/lib/libzfs/libzfs_mount.c
+++ b/lib/libzfs/libzfs_mount.c
@@ -269,7 +269,7 @@ do_mount(const char *src, const char *mntpt, char *opts)
 	int rc;
 
 	/* Return only the most critical mount error */
-	rc = libzfs_run_process(argv[0], argv);
+	rc = libzfs_run_process(argv[0], argv, STDOUT_VERBOSE|STDERR_VERBOSE);
 	if (rc) {
 		if (rc & MOUNT_FILEIO)
 			return EIO;
@@ -310,7 +310,7 @@ do_unmount(const char *mntpt, int flags)
 	}
 
 	argv[count] = (char *)mntpt;
-	rc = libzfs_run_process(argv[0], argv);
+	rc = libzfs_run_process(argv[0], argv, STDOUT_VERBOSE|STDERR_VERBOSE);
 
 	return (rc ? EINVAL : 0);
 }
@@ -414,8 +414,10 @@ zfs_mount(zfs_handle_t *zhp, const char *options, int flags)
 static int
 unmount_one(libzfs_handle_t *hdl, const char *mountpoint, int flags)
 {
-	if (do_unmount(mountpoint, flags) != 0) {
-		zfs_error_aux(hdl, strerror(errno));
+	int error;
+
+	error = do_unmount(mountpoint, flags);
+	if (error != 0) {
 		return (zfs_error_fmt(hdl, EZFS_UMOUNTFAILED,
 		    dgettext(TEXT_DOMAIN, "cannot unmount '%s'"),
 		    mountpoint));
diff --git a/lib/libzfs/libzfs_util.c b/lib/libzfs/libzfs_util.c
index 163cd1671fa9..da1b9bcddf82 100644
--- a/lib/libzfs/libzfs_util.c
+++ b/lib/libzfs/libzfs_util.c
@@ -632,15 +632,19 @@ libzfs_module_loaded(const char *module)
 }
 
 int
-libzfs_run_process(const char *path, char *argv[])
+libzfs_run_process(const char *path, char *argv[], int flags)
 {
 	pid_t pid;
 	int rc;
 
 	pid = vfork();
 	if (pid == 0) {
-		close(1);
-		close(2);
+		if (!(flags & STDOUT_VERBOSE))
+			close(STDOUT_FILENO);
+
+		if (!(flags & STDERR_VERBOSE))
+			close(STDERR_FILENO);
+
 		(void) execvp(path, argv);
 		_exit(-1);
 	} else if (pid > 0) {
@@ -665,7 +669,7 @@ libzfs_load_module(const char *module)
 	if (libzfs_module_loaded(module))
 		return 0;
 
-	return libzfs_run_process("/sbin/modprobe", argv);
+	return libzfs_run_process("/sbin/modprobe", argv, 0);
 }
 
 libzfs_handle_t *