diff --git a/fs/lustre/include/lustre_import.h b/fs/lustre/include/lustre_import.h
index ac46aaef09bf..4789bba8a0b9 100644
--- a/fs/lustre/include/lustre_import.h
+++ b/fs/lustre/include/lustre_import.h
@@ -198,8 +198,10 @@ struct obd_import {
 
 	/** List of not replied requests */
 	struct list_head		imp_unreplied_list;
-	/** Known maximal replied XID */
+	/** XID below which we know all replies have been received */
 	u64				imp_known_replied_xid;
+	/** highest XID for which we have received a reply */
+	u64				imp_highest_replied_xid;
 
 	/** obd device for this import */
 	struct obd_device	       *imp_obd;
diff --git a/fs/lustre/include/obd_support.h b/fs/lustre/include/obd_support.h
index 55196ce8e3f4..ab7899cd1384 100644
--- a/fs/lustre/include/obd_support.h
+++ b/fs/lustre/include/obd_support.h
@@ -369,6 +369,7 @@ extern char obd_jobid_var[];
 #define OBD_FAIL_PTLRPC_CONNECT_RACE			0x531
 #define OBD_FAIL_PTLRPC_IDLE_RACE			0x533
 #define OBD_FAIL_PTLRPC_ENQ_RESEND			0x534
+#define OBD_FAIL_PTLRPC_DELAY_SEND_FAIL			0x535
 
 #define OBD_FAIL_OBD_PING_NET				0x600
 /*	OBD_FAIL_OBD_LOG_CANCEL_NET	0x601 obsolete since 1.5 */
diff --git a/fs/lustre/ptlrpc/client.c b/fs/lustre/ptlrpc/client.c
index 13c27977b14d..7a267e67e45c 100644
--- a/fs/lustre/ptlrpc/client.c
+++ b/fs/lustre/ptlrpc/client.c
@@ -1289,12 +1289,9 @@ static int ptlrpc_import_delay_req(struct obd_import *imp,
  * Return:	false if no message should be printed
  *		true if console message should be printed
  */
-static bool ptlrpc_console_allow(struct ptlrpc_request *req)
+static bool ptlrpc_console_allow(struct ptlrpc_request *req, u32 opc, int err)
 {
-	u32 opc;
-
 	LASSERT(req->rq_reqmsg);
-	opc = lustre_msg_get_opc(req->rq_reqmsg);
 
 	/* Suppress particular reconnect errors which are to be expected. */
 	if (opc == OST_CONNECT || opc == MDS_CONNECT || opc == MGS_CONNECT) {
@@ -1316,6 +1313,15 @@ static bool ptlrpc_console_allow(struct ptlrpc_request *req)
 			return false;
 	}
 
+	if (opc == LDLM_ENQUEUE && err == -EAGAIN)
+		/* -EAGAIN is normal when using POSIX flocks */
+		return false;
+
+	if (opc == OBD_PING && (err == -ENODEV || err == -ENOTCONN) &&
+	    (req->rq_xid & 0xf) != 10)
+		/* Suppress most ping requests, they may fail occasionally */
+		return false;
+
 	return true;
 }
 
@@ -1334,8 +1340,7 @@ static int ptlrpc_check_status(struct ptlrpc_request *req)
 		u32 opc = lustre_msg_get_opc(req->rq_reqmsg);
 
 		/* -EAGAIN is normal when using POSIX flocks */
-		if (ptlrpc_console_allow(req) &&
-		    !(opc == LDLM_ENQUEUE && rc == -EAGAIN))
+		if (ptlrpc_console_allow(req, opc, rc))
 			LCONSOLE_ERROR_MSG(0x011,
 					   "%s: operation %s to node %s failed: rc = %d\n",
 					   imp->imp_obd->obd_name,
@@ -2226,13 +2231,19 @@ EXPORT_SYMBOL(ptlrpc_check_set);
 int ptlrpc_expire_one_request(struct ptlrpc_request *req, int async_unlink)
 {
 	struct obd_import *imp = req->rq_import;
+	unsigned int debug_mask = D_RPCTRACE;
 	int rc = 0;
+	u32 opc;
 
 	spin_lock(&req->rq_lock);
 	req->rq_timedout = 1;
 	spin_unlock(&req->rq_lock);
 
-	DEBUG_REQ(D_WARNING, req, "Request sent has %s: [sent %lld/real %lld]",
+	opc = lustre_msg_get_opc(req->rq_reqmsg);
+	if (ptlrpc_console_allow(req, opc,
+				 lustre_msg_get_status(req->rq_reqmsg)))
+		debug_mask = D_WARNING;
+	DEBUG_REQ(debug_mask, req, "Request sent has %s: [sent %lld/real %lld]",
 		  req->rq_net_err ? "failed due to network error" :
 		     ((req->rq_real_sent == 0 ||
 		       req->rq_real_sent < req->rq_sent ||
@@ -2286,7 +2297,9 @@ int ptlrpc_expire_one_request(struct ptlrpc_request *req, int async_unlink)
 		rc = 1;
 	}
 
-	ptlrpc_fail_import(imp, lustre_msg_get_conn_cnt(req->rq_reqmsg));
+	if (opc != OBD_PING || req->rq_xid > imp->imp_highest_replied_xid)
+		ptlrpc_fail_import(imp,
+				   lustre_msg_get_conn_cnt(req->rq_reqmsg));
 
 	return rc;
 }
diff --git a/fs/lustre/ptlrpc/events.c b/fs/lustre/ptlrpc/events.c
index 17ef775923db..93ff704ac4ec 100644
--- a/fs/lustre/ptlrpc/events.c
+++ b/fs/lustre/ptlrpc/events.c
@@ -171,6 +171,9 @@ void reply_in_callback(struct lnet_event *ev)
 	if (lustre_msg_get_opc(req->rq_reqmsg) != OBD_PING)
 		req->rq_import->imp_last_reply_time = ktime_get_real_seconds();
 
+	if (req->rq_xid > req->rq_import->imp_highest_replied_xid)
+		req->rq_import->imp_highest_replied_xid = req->rq_xid;
+
 out_wake:
 	/* NB don't unlock till after wakeup; req can disappear under us
 	 * since we don't have our own ref
diff --git a/fs/lustre/ptlrpc/niobuf.c b/fs/lustre/ptlrpc/niobuf.c
index 09f68157b883..ccc2caab3876 100644
--- a/fs/lustre/ptlrpc/niobuf.c
+++ b/fs/lustre/ptlrpc/niobuf.c
@@ -725,6 +725,10 @@ int ptl_send_rpc(struct ptlrpc_request *request, int noreply)
 	request->rq_deadline = request->rq_sent + request->rq_timeout +
 			       ptlrpc_at_get_net_latency(request);
 
+	if (unlikely(opc == OBD_PING &&
+	    OBD_FAIL_TIMEOUT(OBD_FAIL_PTLRPC_DELAY_SEND_FAIL, cfs_fail_val)))
+		goto skip_send;
+
 	DEBUG_REQ(D_INFO, request, "send flags=%x",
 		  lustre_msg_get_flags(request->rq_reqmsg));
 	rc = ptl_send_buf(&request->rq_req_md_h,
@@ -737,6 +741,7 @@ int ptl_send_rpc(struct ptlrpc_request *request, int noreply)
 	if (likely(rc == 0))
 		goto out;
 
+skip_send:
 	request->rq_req_unlinked = 1;
 	ptlrpc_req_finished(request);
 	if (noreply)
