diff -Nuar qemu-4497/vl.c qemu-mod/vl.c
--- qemu-4497/vl.c	2008-05-19 12:26:46.000000000 +0300
+++ qemu-mod/vl.c	2008-05-19 12:30:51.000000000 +0300
@@ -6407,7 +6407,7 @@
     return 0;
 }
 
-#define BDRV_HASH_BLOCK_SIZE 1024
+#define BDRV_HASH_BLOCK_SIZE 16384
 #define IOBUF_SIZE 4096
 #define RAM_CBLOCK_MAGIC 0xfabe