--- sys/boot/zfs/zfs.c.orig	2011-10-20 18:15:29.966685430 +0000
+++ sys/boot/zfs/zfs.c	2011-10-20 18:18:22.291033636 +0000
@@ -45,6 +45,12 @@
 
 #include "zfsimpl.c"
 
+/*
+ * For GPT this should be 128 but leads to 50+ second delay in BTX loader so
+ * we use the original 4 pre r198420 by default for the boot process
+ */
+#define ZFS_MAX_SLICES 4
+
 static int	zfs_open(const char *path, struct open_file *f);
 static int	zfs_write(struct open_file *f, void *buf, size_t size, size_t *resid);
 static int	zfs_close(struct open_file *f);
@@ -415,7 +421,7 @@
 		if (vdev_probe(vdev_read, (void*) (uintptr_t) fd, 0))
 			close(fd);
 
-		for (slice = 1; slice <= 128; slice++) {
+		for (slice = 1; slice <= ZFS_MAX_SLICES; slice++) {
 			sprintf(devname, "disk%dp%d:", unit, slice);
 			fd = open(devname, O_RDONLY);
 			if (fd == -1) {