Only in xen-2.0-new/tools/python/xen/lowlevel/xu: xu.c~
diff -ur xen-2.0/tools/python/xen/xend/server/blkif.py xen-2.0-new/tools/python/xen/xend/server/blkif.py
--- xen-2.0/tools/python/xen/xend/server/blkif.py	2005-01-03 21:46:13.000000000 -0600
+++ xen-2.0-new/tools/python/xen/xend/server/blkif.py	2005-01-12 18:40:17.648463000 -0600
@@ -63,6 +63,12 @@
         log.debug("exception looking up device number for %s: %s", name, ex)
 	pass
 
+    if re.match( '/dev/sd[a-p]([0-9]|1[0-5])', n):
+        return 8 * 256 + 16 * (ord(n[7:8]) - ord('a')) + int(n[8:])
+
+    if re.match( '/dev/hd[a-p]([0-9]|[1-5][0-9]|6[0-3])', n):
+        return 3 * 256 + 16 * (ord(n[7:8]) - ord('a')) + int(n[8:])        
+
     # see if this is a hex device number
     if re.match( '^(0x)?[0-9a-fA-F]+$', name ):
 	return string.atoi(name,16)