diff --git a/cmd/zed/zed.d/all-syslog.sh b/cmd/zed/zed.d/all-syslog.sh
index cb9286500136..270b1bc67e5c 100755
--- a/cmd/zed/zed.d/all-syslog.sh
+++ b/cmd/zed/zed.d/all-syslog.sh
@@ -1,14 +1,50 @@
 #!/bin/sh
+#
+# Copyright (C) 2013-2014 Lawrence Livermore National Security, LLC.
+# Copyright (c) 2020 by Delphix. All rights reserved.
+#
+
 #
 # Log the zevent via syslog.
+#
 
 [ -f "${ZED_ZEDLET_DIR}/zed.rc" ] && . "${ZED_ZEDLET_DIR}/zed.rc"
 . "${ZED_ZEDLET_DIR}/zed-functions.sh"
 
 zed_exit_if_ignoring_this_event
 
-zed_log_msg "eid=${ZEVENT_EID}" "class=${ZEVENT_SUBCLASS}" \
-    "${ZEVENT_POOL_GUID:+"pool_guid=${ZEVENT_POOL_GUID}"}" \
-    "${ZEVENT_VDEV_PATH:+"vdev_path=${ZEVENT_VDEV_PATH}"}" \
-    "${ZEVENT_VDEV_STATE_STR:+"vdev_state=${ZEVENT_VDEV_STATE_STR}"}"
+# build a string of name=value pairs for this event
+msg="eid=${ZEVENT_EID} class=${ZEVENT_SUBCLASS}"
+
+if [ "${ZED_SYSLOG_DISPLAY_GUIDS}" = "1" ]; then
+    [ -n "${ZEVENT_POOL_GUID}" ] && msg="${msg} pool_guid=${ZEVENT_POOL_GUID}"
+    [ -n "${ZEVENT_VDEV_GUID}" ] && msg="${msg} vdev_guid=${ZEVENT_VDEV_GUID}"
+else
+    [ -n "${ZEVENT_POOL}" ] && msg="${msg} pool='${ZEVENT_POOL}'"
+    [ -n "${ZEVENT_VDEV_PATH}" ] && msg="${msg} vdev=$(basename "${ZEVENT_VDEV_PATH}")"
+fi
+
+# log pool state if state is anything other than 'ACTIVE'
+[ -n "${ZEVENT_POOL_STATE_STR}" ] && [ "$ZEVENT_POOL_STATE" -ne 0 ] && \
+    msg="${msg} pool_state=${ZEVENT_POOL_STATE_STR}"
+
+# Log the following payload nvpairs if they are present
+[ -n "${ZEVENT_VDEV_STATE_STR}" ]  && msg="${msg} vdev_state=${ZEVENT_VDEV_STATE_STR}"
+[ -n "${ZEVENT_CKSUM_ALGORITHM}" ] && msg="${msg} algorithm=${ZEVENT_CKSUM_ALGORITHM}"
+[ -n "${ZEVENT_ZIO_SIZE}" ]        && msg="${msg} size=${ZEVENT_ZIO_SIZE}"
+[ -n "${ZEVENT_ZIO_OFFSET}" ]      && msg="${msg} offset=${ZEVENT_ZIO_OFFSET}"
+[ -n "${ZEVENT_ZIO_PRIORITY}" ]    && msg="${msg} priority=${ZEVENT_ZIO_PRIORITY}"
+[ -n "${ZEVENT_ZIO_ERR}" ]         && msg="${msg} err=${ZEVENT_ZIO_ERR}"
+[ -n "${ZEVENT_ZIO_FLAGS}" ]       && msg="${msg} flags=$(printf '0x%x' "${ZEVENT_ZIO_FLAGS}")"
+
+# log delays that are >= 10 milisec
+[ -n "${ZEVENT_ZIO_DELAY}" ] && [ "$ZEVENT_ZIO_DELAY" -gt 10000000 ] && \
+    msg="${msg} delay=$((ZEVENT_ZIO_DELAY / 1000000))ms"
+
+# list the bookmark data together
+[ -n "${ZEVENT_ZIO_OBJSET}" ] && \
+    msg="${msg} bookmark=${ZEVENT_ZIO_OBJSET}:${ZEVENT_ZIO_OBJECT}:${ZEVENT_ZIO_LEVEL}:${ZEVENT_ZIO_BLKID}"
+
+zed_log_msg "${msg}"
+
 exit 0
diff --git a/cmd/zed/zed.d/zed.rc b/cmd/zed/zed.d/zed.rc
index 1b220d28db20..df560f921e60 100644
--- a/cmd/zed/zed.d/zed.rc
+++ b/cmd/zed/zed.d/zed.rc
@@ -118,5 +118,10 @@ ZED_USE_ENCLOSURE_LEDS=1
 # Otherwise, if ZED_SYSLOG_SUBCLASS_EXCLUDE is set, the
 # matching subclasses are excluded from logging.
 #ZED_SYSLOG_SUBCLASS_INCLUDE="checksum|scrub_*|vdev.*"
-#ZED_SYSLOG_SUBCLASS_EXCLUDE="statechange|config_*|history_event"
+ZED_SYSLOG_SUBCLASS_EXCLUDE="history_event"
+
+##
+# Use GUIDs instead of names when logging pool and vdevs
+# Disabled by default, 1 to enable and 0 to disable.
+#ZED_SYSLOG_DISPLAY_GUIDS=1
 
diff --git a/tests/zfs-tests/tests/functional/events/events_001_pos.ksh b/tests/zfs-tests/tests/functional/events/events_001_pos.ksh
index 5121f66b78b0..189cf435e88e 100755
--- a/tests/zfs-tests/tests/functional/events/events_001_pos.ksh
+++ b/tests/zfs-tests/tests/functional/events/events_001_pos.ksh
@@ -94,22 +94,22 @@ run_and_verify -p "$MPOOL"\
     -e "resource.fs.zfs.statechange" \
     -e "sysevent.fs.zfs.config_sync" \
     "zpool offline $MPOOL $VDEV1"
-run_and_verify -p "$MPOOL" -d 10 \
+run_and_verify -p "$MPOOL" \
     -e "resource.fs.zfs.statechange" \
     -e "sysevent.fs.zfs.vdev_online" \
-    -e "sysevent.fs.zfs.resilver_start" \
-    -e "sysevent.fs.zfs.resilver_finish" \
-    -e "sysevent.fs.zfs.history_event" \
     -e "sysevent.fs.zfs.config_sync" \
+    -e "sysevent.fs.zfs.resilver_start" \
+    -e "sysevent.fs.zfs.history_event" \
+    -e "sysevent.fs.zfs.resilver_finish" \
     "zpool online $MPOOL $VDEV1"
 
 # Attach then detach a device from the mirror.
-run_and_verify -p "$MPOOL" -d 10 \
+run_and_verify -p "$MPOOL" \
     -e "sysevent.fs.zfs.vdev_attach" \
     -e "sysevent.fs.zfs.resilver_start" \
-    -e "sysevent.fs.zfs.resilver_finish" \
-    -e "sysevent.fs.zfs.history_event" \
     -e "sysevent.fs.zfs.config_sync" \
+    -e "sysevent.fs.zfs.history_event" \
+    -e "sysevent.fs.zfs.resilver_finish" \
     "zpool attach $MPOOL $VDEV1 $VDEV4"
 run_and_verify -p "$MPOOL" \
     -e "sysevent.fs.zfs.vdev_remove" \
@@ -117,20 +117,20 @@ run_and_verify -p "$MPOOL" \
     "zpool detach $MPOOL $VDEV4"
 
 # Replace a device
-run_and_verify -p "$MPOOL" -d 10 \
+run_and_verify -p "$MPOOL" \
     -e "sysevent.fs.zfs.vdev_attach" \
     -e "sysevent.fs.zfs.resilver_start" \
+    -e "sysevent.fs.zfs.config_sync" \
+    -e "sysevent.fs.zfs.history_event" \
     -e "sysevent.fs.zfs.resilver_finish" \
     -e "sysevent.fs.zfs.vdev_remove" \
-    -e "sysevent.fs.zfs.history_event" \
-    -e "sysevent.fs.zfs.config_sync" \
     "zpool replace -f $MPOOL $VDEV1 $VDEV4"
 
 # Scrub a pool.
-run_and_verify -p "$MPOOL" -d 10 \
+run_and_verify -p "$MPOOL" \
     -e "sysevent.fs.zfs.scrub_start" \
-    -e "sysevent.fs.zfs.scrub_finish" \
     -e "sysevent.fs.zfs.history_event" \
+    -e "sysevent.fs.zfs.scrub_finish" \
     "zpool scrub $MPOOL"
 
 # Export then import a pool
@@ -139,9 +139,9 @@ run_and_verify -p "$MPOOL" \
     -e "sysevent.fs.zfs.config_sync" \
     "zpool export $MPOOL"
 run_and_verify -p "$MPOOL" \
-    -e "sysevent.fs.zfs.pool_import" \
-    -e "sysevent.fs.zfs.history_event" \
     -e "sysevent.fs.zfs.config_sync" \
+    -e "sysevent.fs.zfs.history_event" \
+    -e "sysevent.fs.zfs.pool_import" \
     "zpool import -d $TEST_BASE_DIR $MPOOL"
 
 # Destroy the pool
diff --git a/tests/zfs-tests/tests/functional/events/events_002_pos.ksh b/tests/zfs-tests/tests/functional/events/events_002_pos.ksh
index 76ad6237fc23..7a78d93a8438 100755
--- a/tests/zfs-tests/tests/functional/events/events_002_pos.ksh
+++ b/tests/zfs-tests/tests/functional/events/events_002_pos.ksh
@@ -92,7 +92,7 @@ done
 
 # 5. Start the ZED and verify it only handled the new missed events.
 log_must zed_start
-log_must file_wait $ZED_DEBUG_LOG 15
+log_must file_wait $ZED_DEBUG_LOG 35
 log_must cp $ZED_DEBUG_LOG $TMP_EVENTS_ZED
 
 log_mustnot grep -q "sysevent.fs.zfs.pool_create" $TMP_EVENTS_ZED
diff --git a/tests/zfs-tests/tests/functional/events/events_common.kshlib b/tests/zfs-tests/tests/functional/events/events_common.kshlib
index 26afc109174f..5f4c629dca47 100644
--- a/tests/zfs-tests/tests/functional/events/events_common.kshlib
+++ b/tests/zfs-tests/tests/functional/events/events_common.kshlib
@@ -23,10 +23,34 @@
 # Copyright (c) 2017 by Lawrence Livermore National Security, LLC.
 # Use is subject to license terms.
 #
+# Copyright (c) 2020 by Delphix. All rights reserved.
+#
 
 . $STF_SUITE/include/libtest.shlib
 . $STF_SUITE/tests/functional/events/events.cfg
 
+#
+# wait for 'event' to show up in the log 'file'
+function file_wait_event # file event timeout
+{
+	file=$1
+	event=$2
+	timeout=${3:-120}
+
+	SECONDS=0
+
+	until grep -q "^ZEVENT_CLASS=$event" $ZED_DEBUG_LOG ; do
+		if [[ $SECONDS -gt $timeout ]]; then
+			echo file_wait_event exceeded $SECONDS seconds
+			return 1
+		fi
+
+		sleep 1
+	done
+
+	return 0;
+}
+
 #
 # Wait for up to 'timeout' seconds for the 'file' to settle, i.e.
 # not be updated for a period of 'delay' seconds.
@@ -41,6 +65,7 @@ function file_wait # file delay timeout
 
 	while [ $(( $(date +%s) - $(stat -c %Y $file) )) -lt $delay ]; do
 		if [[ $SECONDS -gt $timeout ]]; then
+			echo file_wait exceeded $SECONDS seconds
 			return 1
 		fi
 
@@ -52,30 +77,22 @@ function file_wait # file delay timeout
 
 function run_and_verify
 {
-	typeset delay event pool zedlog
+	typeset event pool
 	set -A events
 
-	while getopts "d:e:p:z:" opt; do
+	while getopts "e:p:" opt; do
 		case $opt in
-		d)
-			delay=$OPTARG
-			;;
 		e)
-			events[${#events[*]}+1]=$OPTARG
+			events+=("$OPTARG")
 			;;
 		p)
 			pool=$OPTARG
 			;;
-		z)
-			zedlog=$OPTARG
-			;;
 		esac
 	done
 	shift $(($OPTIND - 1))
 
 	pool=${pool:-$TESTPOOL}
-	delay=${delay:-3}
-	zedlog=${zedlog:-$ZED_DEBUG_LOG}
 	fullcmd="$1"
 	cmd=$(echo $fullcmd | awk '{print $1}')
 
@@ -87,21 +104,30 @@ function run_and_verify
 
 	# Remove any previous events from the logs.
 	log_must zpool events -c
-	log_must truncate -s 0 $zedlog
+	log_must truncate -s 0 $ZED_DEBUG_LOG
 
 	# Run the command as provided.
 	log_must eval "$fullcmd"
 
 	# Collect the new events and verify there are some.
 	log_must zpool sync -f
-	log_must file_wait $zedlog $delay
-	log_must cp $zedlog $TMP_EVENTS_ZED
 	log_must eval "zpool events >$TMP_EVENTS 2>/dev/null"
 	log_must eval "zpool events -v > $TMP_EVENTS_FULL 2>/dev/null"
 
 	log_must test -s $TMP_EVENTS
 	log_must test -s $TMP_EVENTS_FULL
-	log_must test -s $TMP_EVENTS_ZED
+
+	# If the only event is history then we don't observe zed debug log
+	if [[ "${events[0]}" != "sysevent.fs.zfs.history_event" ]]; then
+		# wait for the last event to show up in the debug log
+		log_must file_wait_event $ZED_DEBUG_LOG ${events[-1]}
+
+		log_must cp $ZED_DEBUG_LOG $TMP_EVENTS_ZED
+		log_must test -s $TMP_EVENTS_ZED
+
+		log_note "Events logged:"
+		grep "^ZEVENT_CLASS" $TMP_EVENTS_ZED
+	fi
 
 	log_note "Events generated:"
 	cat $TMP_EVENTS
@@ -118,6 +144,11 @@ function run_and_verify
 		    $TMP_EVENTS_FULL >$TMP_EVENT_FULL
 		log_must grep -q "pool = \"$pool\"" $TMP_EVENT_FULL
 
+		# all-debug.sh filters history events (seen in ZED_DEBUG_LOG)
+		if [[ "$event" == "sysevent.fs.zfs.history_event" ]]; then
+			continue
+		fi
+
 		# Verify the event was received by the ZED and logged.
 		awk -v event="$event" \
 		    'BEGIN{FS="\n"; RS=""} $0 ~ event { print $0 }' \