diff --git a/ChangeLog b/ChangeLog
index b78bdcce0..44e8badf2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2010-11-19  Vladimir Serbinenko  <phcoder@gmail.com>
+
+	* grub-core/disk/mdraid1x_linux.c (grub_mdraid_detect): Don't try to
+	retrieve the metadat sector if size isn't known.
+	* grub-core/disk/mdraid_linux.c (grub_mdraid_detect): Likewise.
+
 2010-11-18  Robert Millan  <rmh@gnu.org>
 
 	* grub-core/fs/btrfs.c (grub_btrfs_mount): Replace grub_strncmp()
diff --git a/grub-core/disk/mdraid1x_linux.c b/grub-core/disk/mdraid1x_linux.c
index dd60df695..b1fce86a0 100644
--- a/grub-core/disk/mdraid1x_linux.c
+++ b/grub-core/disk/mdraid1x_linux.c
@@ -123,6 +123,9 @@ grub_mdraid_detect (grub_disk_t disk, struct grub_raid_array *array,
 
   for (minor_version = 0; minor_version < 3; ++minor_version)
     {
+      if (size == GRUB_DISK_SIZE_UNKNOWN && minor_version == 0)
+	continue;
+	
       switch (minor_version)
 	{
 	case 0:
diff --git a/grub-core/disk/mdraid_linux.c b/grub-core/disk/mdraid_linux.c
index f5cad9dbf..dc0d80ffd 100644
--- a/grub-core/disk/mdraid_linux.c
+++ b/grub-core/disk/mdraid_linux.c
@@ -170,6 +170,8 @@ grub_mdraid_detect (grub_disk_t disk, struct grub_raid_array *array,
 
   /* The sector where the mdraid 0.90 superblock is stored, if available.  */
   size = grub_disk_get_size (disk);
+  if (size == GRUB_DISK_SIZE_UNKNOWN)
+    return grub_error (GRUB_ERR_OUT_OF_RANGE, "not 0.9x raid");
   sector = NEW_SIZE_SECTORS (size);
 
   if (grub_disk_read (disk, sector, 0, SB_BYTES, &sb))