diff --git a/dom0/qmemman/qmemman_algo.py b/dom0/qmemman/qmemman_algo.py
index f0d3d95c..d8c1f6b2 100755
--- a/dom0/qmemman/qmemman_algo.py
+++ b/dom0/qmemman/qmemman_algo.py
@@ -58,7 +58,7 @@ def refresh_meminfo_for_domain(domain, untrusted_xenstore_key):
                         
 def prefmem(domain):
     CACHE_FACTOR = 1.3
-    MIN_PREFMEM = 100*1024*1024
+    MIN_PREFMEM = 200*1024*1024
 #dom0 is special, as it must have large cache, for vbds. Thus, give it a special boost
     if domain.id == '0':
         return min(domain.mem_used*CACHE_FACTOR + 350*1024*1024, domain.memory_maximum)