diff --git a/tools/ocaml/xenstored/define.ml b/tools/ocaml/xenstored/define.ml
index 89a6aacc88..d60861ca34 100644
--- a/tools/ocaml/xenstored/define.ml
+++ b/tools/ocaml/xenstored/define.ml
@@ -27,6 +27,7 @@ let default_config_dir = "/etc/xen"
 
 let maxwatch = ref (50)
 let maxtransaction = ref (20)
+let maxrequests = ref (-1)   (* maximum requests per transaction *)
 
 let domid_self = 0x7FF0
 
diff --git a/tools/ocaml/xenstored/oxenstored.conf b/tools/ocaml/xenstored/oxenstored.conf
index dd20eda140..ac60f49df8 100644
--- a/tools/ocaml/xenstored/oxenstored.conf
+++ b/tools/ocaml/xenstored/oxenstored.conf
@@ -18,6 +18,7 @@ quota-maxentity = 1000
 quota-maxsize = 2048
 quota-maxwatch = 100
 quota-transaction = 10
+quota-maxrequests = 1024
 
 # Activate filed base backend
 persistent = false
diff --git a/tools/ocaml/xenstored/process.ml b/tools/ocaml/xenstored/process.ml
index c92bec7bef..758ade191d 100644
--- a/tools/ocaml/xenstored/process.ml
+++ b/tools/ocaml/xenstored/process.ml
@@ -155,7 +155,7 @@ let do_transaction_end con t domains cons data =
 	if not success then
 		raise Transaction_again;
 	if commit then
-		process_watch (List.rev (Transaction.get_ops t)) cons
+		process_watch (List.rev (Transaction.get_paths t)) cons
 
 let do_introduce con t domains cons data =
 	if not (Connection.is_dom0 con)
@@ -303,7 +303,7 @@ let reply_ack fct con t doms cons data =
 	fct con t doms cons data;
 	Packet.Ack (fun () ->
 		if Transaction.get_id t = Transaction.none then
-			process_watch (Transaction.get_ops t) cons
+			process_watch (Transaction.get_paths t) cons
 	)
 
 let reply_data fct con t doms cons data =
@@ -384,6 +384,15 @@ let process_packet ~store ~cons ~doms ~con ~req =
 			in
 		let response = input_handle_error ~cons ~doms ~fct ~con ~t ~req in
 
+		let response = try
+			if tid <> Transaction.none then
+				(* Remember the request and response for this operation in case we need to replay the transaction *)
+				Transaction.add_operation ~perm:(Connection.get_perm con) t req response;
+			response
+		with Quota.Limit_reached ->
+			Packet.Error "EQUOTA"
+		in
+
 		(* Put the response on the wire *)
 		send_response ty con t rid response
 	with exn ->
diff --git a/tools/ocaml/xenstored/transaction.ml b/tools/ocaml/xenstored/transaction.ml
index 77de4e8ac1..6b37fc2ad0 100644
--- a/tools/ocaml/xenstored/transaction.ml
+++ b/tools/ocaml/xenstored/transaction.ml
@@ -75,7 +75,8 @@ type t = {
 	ty: ty;
 	store: Store.t;
 	quota: Quota.t;
-	mutable ops: (Xenbus.Xb.Op.operation * Store.Path.t) list;
+	mutable paths: (Xenbus.Xb.Op.operation * Store.Path.t) list;
+	mutable operations: (Packet.request * Packet.response) list;
 	mutable read_lowpath: Store.Path.t option;
 	mutable write_lowpath: Store.Path.t option;
 }
@@ -86,16 +87,24 @@ let make id store =
 		ty = ty;
 		store = if id = none then store else Store.copy store;
 		quota = Quota.copy store.Store.quota;
-		ops = [];
+		paths = [];
+		operations = [];
 		read_lowpath = None;
 		write_lowpath = None;
 	}
 
 let get_id t = match t.ty with No -> none | Full (id, _, _) -> id
 let get_store t = t.store
-let get_ops t = t.ops
+let get_paths t = t.paths
 
-let add_wop t ty path = t.ops <- (ty, path) :: t.ops
+let add_wop t ty path = t.paths <- (ty, path) :: t.paths
+let add_operation ~perm t request response =
+	if !Define.maxrequests >= 0
+		&& not (Perms.Connection.is_dom0 perm)
+		&& List.length t.operations >= !Define.maxrequests
+		then raise Quota.Limit_reached;
+	t.operations <- (request, response) :: t.operations
+let get_operations t = List.rev t.operations
 let set_read_lowpath t path = t.read_lowpath <- get_lowest path t.read_lowpath
 let set_write_lowpath t path = t.write_lowpath <- get_lowest path t.write_lowpath
 
@@ -141,7 +150,7 @@ let getperms t perm path =
 	r
 
 let commit ~con t =
-	let has_write_ops = List.length t.ops > 0 in
+	let has_write_ops = List.length t.paths > 0 in
 	let has_coalesced = ref false in
 	let has_commited =
 	match t.ty with
diff --git a/tools/ocaml/xenstored/xenstored.ml b/tools/ocaml/xenstored/xenstored.ml
index 25c126a78e..fc8cc95d2e 100644
--- a/tools/ocaml/xenstored/xenstored.ml
+++ b/tools/ocaml/xenstored/xenstored.ml
@@ -95,6 +95,7 @@ let parse_config filename =
 		("quota-transaction", Config.Set_int Define.maxtransaction);
 		("quota-maxentity", Config.Set_int Quota.maxent);
 		("quota-maxsize", Config.Set_int Quota.maxsize);
+		("quota-maxrequests", Config.Set_int Define.maxrequests);
 		("test-eagain", Config.Set_bool Transaction.test_eagain);
 		("persistent", Config.Set_bool Disk.enable);
 		("xenstored-log-file", Config.String Logging.set_xenstored_log_destination);