7651 default maximum nfs server threads is insufficient

@@ -20,10 +20,11 @@
  */
 
 /*
  * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
  *  Copyright (c) 1993, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012 by Delphix. All rights reserved.
  */
 
 /*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
 /*        All Rights Reserved   */
 

@@ -711,16 +712,16 @@
 /*
  * MAXDUPREQS is the number of cached items.  It should be adjusted
  * to the service load so that there is likely to be a response entry
  * when the first retransmission comes in.
  */
-#define MAXDUPREQS      1024
+#define MAXDUPREQS      8192
 
 /*
  * This should be appropriately scaled to MAXDUPREQS.
  */
-#define DRHASHSZ        257
+#define DRHASHSZ        2053
 
 #if ((DRHASHSZ & (DRHASHSZ - 1)) == 0)
 #define XIDHASH(xid)    ((xid) & (DRHASHSZ - 1))
 #else
 #define XIDHASH(xid)    ((xid) % DRHASHSZ)