diff --git a/sbin/hastd/Makefile b/sbin/hastd/Makefile
index bfb62f4f11f6..6e3147dcd31e 100644
--- a/sbin/hastd/Makefile
+++ b/sbin/hastd/Makefile
@@ -5,7 +5,7 @@
 PROG=	hastd
 SRCS=	activemap.c
 SRCS+=	control.c
-SRCS+=	ebuf.c
+SRCS+=	ebuf.c event.c
 SRCS+=	hast_proto.c hastd.c hooks.c
 SRCS+=	metadata.c
 SRCS+=	nv.c
diff --git a/sbin/hastd/hast.h b/sbin/hastd/hast.h
index 71379178e767..a42865f0d061 100644
--- a/sbin/hastd/hast.h
+++ b/sbin/hastd/hast.h
@@ -181,6 +181,8 @@ struct hast_resource {
 	pid_t	hr_workerpid;
 	/* Control connection between parent and child. */
 	struct proto_conn *hr_ctrl;
+	/* Events from child to parent. */
+	struct proto_conn *hr_event;
 
 	/* Activemap structure. */
 	struct activemap *hr_amp;
diff --git a/sbin/hastd/hastd.c b/sbin/hastd/hastd.c
index ccc25cfe0f44..6ddcbd2f831e 100644
--- a/sbin/hastd/hastd.c
+++ b/sbin/hastd/hastd.c
@@ -52,6 +52,7 @@ __FBSDID("$FreeBSD$");
 #include <pjdlog.h>
 
 #include "control.h"
+#include "event.h"
 #include "hast.h"
 #include "hast_proto.h"
 #include "hastd.h"
@@ -158,6 +159,11 @@ child_exit(void)
 		    role2str(res->hr_role));
 		child_exit_log(pid, status);
 		proto_close(res->hr_ctrl);
+		res->hr_ctrl = NULL;
+		if (res->hr_event != NULL) {
+			proto_close(res->hr_event);
+			res->hr_event = NULL;
+		}
 		res->hr_workerpid = 0;
 		if (res->hr_role == HAST_ROLE_PRIMARY) {
 			/*
@@ -624,9 +630,10 @@ listen_accept(void)
 static void
 main_loop(void)
 {
-	fd_set rfds;
-	int cfd, lfd, maxfd, ret;
+	struct hast_resource *res;
 	struct timeval timeout;
+	int fd, maxfd, ret;
+	fd_set rfds;
 
 	timeout.tv_sec = REPORT_INTERVAL;
 	timeout.tv_usec = 0;
@@ -646,14 +653,20 @@ main_loop(void)
 			hastd_reload();
 		}
 
-		cfd = proto_descriptor(cfg->hc_controlconn);
-		lfd = proto_descriptor(cfg->hc_listenconn);
-		maxfd = cfd > lfd ? cfd : lfd;
-
 		/* Setup descriptors for select(2). */
 		FD_ZERO(&rfds);
-		FD_SET(cfd, &rfds);
-		FD_SET(lfd, &rfds);
+		maxfd = fd = proto_descriptor(cfg->hc_controlconn);
+		FD_SET(fd, &rfds);
+		fd = proto_descriptor(cfg->hc_listenconn);
+		FD_SET(fd, &rfds);
+		maxfd = fd > maxfd ? fd : maxfd;
+		TAILQ_FOREACH(res, &cfg->hc_resources, hr_next) {
+			if (res->hr_event == NULL)
+				continue;
+			fd = proto_descriptor(res->hr_event);
+			FD_SET(fd, &rfds);
+			maxfd = fd > maxfd ? fd : maxfd;
+		}
 
 		ret = select(maxfd + 1, &rfds, NULL, NULL, &timeout);
 		if (ret == 0)
@@ -665,10 +678,21 @@ main_loop(void)
 			pjdlog_exit(EX_OSERR, "select() failed");
 		}
 
-		if (FD_ISSET(cfd, &rfds))
+		if (FD_ISSET(proto_descriptor(cfg->hc_controlconn), &rfds))
 			control_handle(cfg);
-		if (FD_ISSET(lfd, &rfds))
+		if (FD_ISSET(proto_descriptor(cfg->hc_listenconn), &rfds))
 			listen_accept();
+		TAILQ_FOREACH(res, &cfg->hc_resources, hr_next) {
+			if (res->hr_event == NULL)
+				continue;
+			if (FD_ISSET(proto_descriptor(res->hr_event), &rfds)) {
+				if (event_recv(res) == 0)
+					continue;
+				/* The worker process exited? */
+				proto_close(res->hr_event);
+				res->hr_event = NULL;
+			}
+		}
 	}
 }
 
diff --git a/sbin/hastd/primary.c b/sbin/hastd/primary.c
index e018e89a186f..a8a2d41f87a8 100644
--- a/sbin/hastd/primary.c
+++ b/sbin/hastd/primary.c
@@ -58,6 +58,7 @@ __FBSDID("$FreeBSD$");
 #include <rangelock.h>
 
 #include "control.h"
+#include "event.h"
 #include "hast.h"
 #include "hast_proto.h"
 #include "hastd.h"
@@ -225,12 +226,6 @@ static void *ggate_send_thread(void *arg);
 static void *sync_thread(void *arg);
 static void *guard_thread(void *arg);
 
-static void
-dummy_sighandler(int sig __unused)
-{
-	/* Nothing to do. */
-}
-
 static void
 cleanup(struct hast_resource *res)
 {
@@ -429,8 +424,6 @@ init_environment(struct hast_resource *res __unused)
 	/*
 	 * Turn on signals handling.
 	 */
-	/* Because SIGCHLD is ignored by default, setup dummy handler for it. */
-	PJDLOG_VERIFY(signal(SIGCHLD, dummy_sighandler) != SIG_ERR);
 	PJDLOG_VERIFY(sigfillset(&mask) == 0);
 	PJDLOG_VERIFY(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 }
@@ -672,11 +665,11 @@ init_remote(struct hast_resource *res, struct proto_conn **inp,
 		res->hr_remotein = in;
 		res->hr_remoteout = out;
 	}
-	hook_exec(res->hr_exec, "connect", res->hr_name, NULL);
+	event_send(res, EVENT_CONNECT);
 	return (true);
 close:
 	if (errmsg != NULL && strcmp(errmsg, "Split-brain condition!") == 0)
-		hook_exec(res->hr_exec, "split-brain", res->hr_name, NULL);
+		event_send(res, EVENT_SPLITBRAIN);
 	proto_close(out);
 	if (in != NULL)
 		proto_close(in);
@@ -774,6 +767,14 @@ hastd_primary(struct hast_resource *res)
 		pjdlog_exit(EX_OSERR,
 		    "Unable to create control sockets between parent and child");
 	}
+	/*
+	 * Create communication channel between child and parent.
+	 */
+	if (proto_client("socketpair://", &res->hr_event) < 0) {
+		KEEP_ERRNO((void)pidfile_remove(pfh));
+		pjdlog_exit(EX_OSERR,
+		    "Unable to create event sockets between child and parent");
+	}
 
 	pid = fork();
 	if (pid < 0) {
@@ -783,6 +784,8 @@ hastd_primary(struct hast_resource *res)
 
 	if (pid > 0) {
 		/* This is parent. */
+		/* Declare that we are receiver. */
+		proto_recv(res->hr_event, NULL, 0);
 		res->hr_workerpid = pid;
 		return;
 	}
@@ -797,7 +800,9 @@ hastd_primary(struct hast_resource *res)
 	signal(SIGHUP, SIG_DFL);
 	signal(SIGCHLD, SIG_DFL);
 
-	hook_init();
+	/* Declare that we are sender. */
+	proto_send(res->hr_event, NULL, 0);
+
 	init_local(res);
 	if (real_remote(res) && init_remote(res, NULL, NULL))
 		sync_start();
@@ -896,7 +901,7 @@ remote_close(struct hast_resource *res, int ncomp)
 	 */
 	sync_stop();
 
-	hook_exec(res->hr_exec, "disconnect", res->hr_name, NULL);
+	event_send(res, EVENT_DISCONNECT);
 }
 
 /*
@@ -1512,7 +1517,7 @@ sync_thread(void *arg __unused)
 			pjdlog_info("Synchronization interrupted. "
 			    "%jd bytes synchronized so far.",
 			    (intmax_t)synced);
-			hook_exec(res->hr_exec, "syncintr", res->hr_name, NULL);
+			event_send(res, EVENT_SYNCINTR);
 		}
 		while (!sync_inprogress) {
 			dorewind = true;
@@ -1545,8 +1550,7 @@ sync_thread(void *arg __unused)
 				pjdlog_info("Synchronization started. %ju bytes to go.",
 				    (uintmax_t)(res->hr_extentsize *
 				    activemap_ndirty(res->hr_amp)));
-				hook_exec(res->hr_exec, "syncstart",
-				    res->hr_name, NULL);
+				event_send(res, EVENT_SYNCSTART);
 			}
 		}
 		if (offset < 0) {
@@ -1563,8 +1567,7 @@ sync_thread(void *arg __unused)
 					pjdlog_info("Synchronization complete. "
 					    "%jd bytes synchronized.",
 					    (intmax_t)synced);
-					hook_exec(res->hr_exec, "syncdone",
-					    res->hr_name, NULL);
+					event_send(res, EVENT_SYNCDONE);
 				}
 				mtx_lock(&metadata_lock);
 				res->hr_syncsrc = HAST_SYNCSRC_UNDEF;
@@ -1950,7 +1953,6 @@ guard_thread(void *arg)
 	PJDLOG_VERIFY(sigaddset(&mask, SIGHUP) == 0);
 	PJDLOG_VERIFY(sigaddset(&mask, SIGINT) == 0);
 	PJDLOG_VERIFY(sigaddset(&mask, SIGTERM) == 0);
-	PJDLOG_VERIFY(sigaddset(&mask, SIGCHLD) == 0);
 
 	timeout.tv_nsec = 0;
 	signo = -1;
@@ -1969,7 +1971,6 @@ guard_thread(void *arg)
 		default:
 			break;
 		}
-		hook_check(signo == SIGCHLD);
 
 		pjdlog_debug(2, "remote_guard: Checking connections.");
 		now = time(NULL);
diff --git a/sbin/hastd/secondary.c b/sbin/hastd/secondary.c
index d1575e8a5a7e..14016f703db1 100644
--- a/sbin/hastd/secondary.c
+++ b/sbin/hastd/secondary.c
@@ -54,6 +54,7 @@ __FBSDID("$FreeBSD$");
 #include <pjdlog.h>
 
 #include "control.h"
+#include "event.h"
 #include "hast.h"
 #include "hast_proto.h"
 #include "hastd.h"
@@ -325,7 +326,7 @@ init_remote(struct hast_resource *res, struct nv *nvin)
 	if (res->hr_secondary_localcnt > res->hr_primary_remotecnt &&
 	     res->hr_primary_localcnt > res->hr_secondary_remotecnt) {
 		/* Exit on split-brain. */
-		hook_exec(res->hr_exec, "split-brain", res->hr_name, NULL);
+		event_send(res, EVENT_SPLITBRAIN);
 		exit(EX_CONFIG);
 	}
 }
@@ -345,6 +346,14 @@ hastd_secondary(struct hast_resource *res, struct nv *nvin)
 		pjdlog_exit(EX_OSERR,
 		    "Unable to create control sockets between parent and child");
 	}
+	/*
+	 * Create communication channel between child and parent.
+	 */
+	if (proto_client("socketpair://", &res->hr_event) < 0) {
+		KEEP_ERRNO((void)pidfile_remove(pfh));
+		pjdlog_exit(EX_OSERR,
+		    "Unable to create event sockets between child and parent");
+	}
 
 	pid = fork();
 	if (pid < 0) {
@@ -358,6 +367,8 @@ hastd_secondary(struct hast_resource *res, struct nv *nvin)
 		res->hr_remotein = NULL;
 		proto_close(res->hr_remoteout);
 		res->hr_remoteout = NULL;
+		/* Declare that we are receiver. */
+		proto_recv(res->hr_event, NULL, 0);
 		res->hr_workerpid = pid;
 		return;
 	}
@@ -372,17 +383,19 @@ hastd_secondary(struct hast_resource *res, struct nv *nvin)
 	signal(SIGHUP, SIG_DFL);
 	signal(SIGCHLD, SIG_DFL);
 
+	/* Declare that we are sender. */
+	proto_send(res->hr_event, NULL, 0);
+
 	/* Error in setting timeout is not critical, but why should it fail? */
 	if (proto_timeout(res->hr_remotein, 0) < 0)
 		pjdlog_errno(LOG_WARNING, "Unable to set connection timeout");
 	if (proto_timeout(res->hr_remoteout, res->hr_timeout) < 0)
 		pjdlog_errno(LOG_WARNING, "Unable to set connection timeout");
 
-	hook_init();
 	init_local(res);
 	init_remote(res, nvin);
 	init_environment();
-	hook_exec(res->hr_exec, "connect", res->hr_name, NULL);
+	event_send(res, EVENT_CONNECT);
 
 	error = pthread_create(&td, NULL, recv_thread, res);
 	assert(error == 0);
@@ -515,7 +528,7 @@ secondary_exit(int exitcode, const char *fmt, ...)
 	va_start(ap, fmt);
 	pjdlogv_errno(LOG_ERR, fmt, ap);
 	va_end(ap);
-	hook_exec(gres->hr_exec, "disconnect", gres->hr_name, NULL);
+	event_send(gres, EVENT_DISCONNECT);
 	exit(exitcode);
 }