diff --git a/cmd/zed/Makefile.am b/cmd/zed/Makefile.am
index 8e4efe919502..f1404dea1363 100644
--- a/cmd/zed/Makefile.am
+++ b/cmd/zed/Makefile.am
@@ -39,17 +39,21 @@ dist_zedexec_SCRIPTS = \
 	$(top_srcdir)/cmd/zed/zed.d/all-debug.sh \
 	$(top_srcdir)/cmd/zed/zed.d/all-syslog.sh \
 	$(top_srcdir)/cmd/zed/zed.d/checksum-email.sh \
+	$(top_srcdir)/cmd/zed/zed.d/checksum-spare.sh \
 	$(top_srcdir)/cmd/zed/zed.d/data-email.sh \
 	$(top_srcdir)/cmd/zed/zed.d/generic-email.sh \
 	$(top_srcdir)/cmd/zed/zed.d/io-email.sh \
+	$(top_srcdir)/cmd/zed/zed.d/io-spare.sh \
 	$(top_srcdir)/cmd/zed/zed.d/resilver.finish-email.sh \
 	$(top_srcdir)/cmd/zed/zed.d/scrub.finish-email.sh
 
 zedconfdefaults = \
 	all-syslog.sh \
 	checksum-email.sh \
+	checksum-spare.sh \
 	data-email.sh \
 	io-email.sh \
+	io-spare.sh \
 	resilver.finish-email.sh \
 	scrub.finish-email.sh
 
diff --git a/cmd/zed/zed.d/checksum-spare.sh b/cmd/zed/zed.d/checksum-spare.sh
new file mode 120000
index 000000000000..f564f932283c
--- /dev/null
+++ b/cmd/zed/zed.d/checksum-spare.sh
@@ -0,0 +1 @@
+io-spare.sh
\ No newline at end of file
diff --git a/cmd/zed/zed.d/io-spare.sh b/cmd/zed/zed.d/io-spare.sh
new file mode 100755
index 000000000000..dd5bf4e0f226
--- /dev/null
+++ b/cmd/zed/zed.d/io-spare.sh
@@ -0,0 +1,125 @@
+#!/bin/sh
+#
+# Replace a device with a hot spare in response to IO or checksum errors.
+# The following actions will be performed automatically when the number
+# of errors exceed the limit set by ZED_SPARE_ON_IO_ERRORS or
+# ZED_SPARE_ON_CHECKSUM_ERRORS.
+#
+# 1) FAULT the device on IO errors, no futher IO will be attempted.
+#    DEGRADE the device on checksum errors, the device is still
+#    functional and can be used to service IO requests.
+# 2) Set the SES fault beacon for the device.
+# 3) Replace the device with a hot spare if any are available.
+#
+# Once the hot sparing operation is complete either the failed device or
+# the hot spare must be manually retired using the 'zpool detach' command.
+# The 'autoreplace' functionality which would normally take care of this
+# under Illumos has not yet been implemented.
+#
+# Full support for autoreplace is planned, but it requires that the full
+# ZFS Diagnosis Engine be ported.  In the meanwhile this script provides
+# the majority of the expected hot spare functionality.
+#
+# Exit codes:
+#  0: replaced by hot spare
+#  1: no hot spare device available
+#  2: hot sparing disabled
+#  3: already faulted or degraded
+#  4: unsupported event class
+#  5: internal error
+#
+test -f "${ZED_SCRIPT_DIR}/zed.rc" && . "${ZED_SCRIPT_DIR}/zed.rc"
+
+test -n "${ZEVENT_POOL}" || exit 5
+test -n "${ZEVENT_SUBCLASS}" || exit 5
+test -n "${ZEVENT_VDEV_PATH}" || exit 5
+test -n "${ZEVENT_VDEV_GUID}" || exit 5
+
+# Defaults to disabled, enable in the zed.rc file.
+ZED_SPARE_ON_IO_ERRORS=${ZED_SPARE_ON_IO_ERRORS:-0}
+ZED_SPARE_ON_CHECKSUM_ERRORS=${ZED_SPARE_ON_CHECKSUM_ERRORS:-0}
+
+if [ ${ZED_SPARE_ON_IO_ERRORS} -eq 0 -a \
+     ${ZED_SPARE_ON_CHECKSUM_ERRORS} -eq 0 ]; then
+	exit 2
+fi
+
+# A lock file is used to serialize execution.
+ZED_LOCKDIR=${ZED_LOCKDIR:-/var/lock}
+LOCKFILE="${ZED_LOCKDIR}/zed.spare.lock"
+
+exec 8> "${LOCKFILE}"
+flock -x 8
+
+# Given a <pool> and <device> return the status, (ONLINE, FAULTED, etc...).
+vdev_status() {
+	local POOL=$1
+	local VDEV=`basename $2`
+
+	${ZPOOL} status ${POOL} | \
+	    awk -v pat="${VDEV}|${VDEV/-part?}" '$0 ~ pat { print $1" "$2 }'
+	return 0
+}
+
+# Fault devices after N I/O errors.
+if [ "${ZEVENT_CLASS}" = "ereport.fs.zfs.io" ]; then
+	ERRORS=`expr ${ZEVENT_VDEV_READ_ERRORS} + ${ZEVENT_VDEV_WRITE_ERRORS}`
+
+	if [ ${ZED_SPARE_ON_IO_ERRORS} -gt 0 -a \
+	     ${ERRORS} -ge ${ZED_SPARE_ON_IO_ERRORS} ]; then
+		ACTION="fault"
+	fi
+# Degrade devices after N checksum errors.
+elif [ "${ZEVENT_CLASS}" = "ereport.fs.zfs.checksum" ]; then
+	ERRORS=${ZEVENT_VDEV_CKSUM_ERRORS}
+
+	if [ ${ZED_SPARE_ON_CHECKSUM_ERRORS} -gt 0 -a \
+	     ${ERRORS} -ge ${ZED_SPARE_ON_CHECKSUM_ERRORS} ]; then
+		ACTION="degrade"
+	fi
+else
+	ACTION=
+fi
+
+if [ -n "${ACTION}" ]; then
+
+	# Device is already FAULTED or DEGRADED
+	set -- `vdev_status ${ZEVENT_POOL} ${ZEVENT_VDEV_PATH}`
+	ZEVENT_VDEV_PATH_FOUND=$1
+	STATUS=$2
+	if [ "${STATUS}" = "FAULTED" -o "${STATUS}" = "DEGRADED" ]; then
+		exit 3
+	fi
+
+	# Step 1) FAULT or DEGRADE the device
+	#
+	${ZINJECT} -d ${ZEVENT_VDEV_GUID} -A ${ACTION} ${ZEVENT_POOL}
+
+	# Step 2) Set the SES fault beacon.
+	#
+	# XXX: Set the 'fault' or 'ident' beacon for the device.  This can
+	# be done through the sg_ses utility, the only hard part is to map
+	# the sd device to its corresponding enclosure and slot.  We may
+	# be able to leverage the existing vdev_id scripts for this.
+	#
+	# $ sg_ses --dev-slot-num=0 --set=ident /dev/sg3
+	# $ sg_ses --dev-slot-num=0 --clear=ident /dev/sg3
+
+	# Step 3) Replace the device with a hot spare.
+	#
+	# Round robin through the spares selecting those which are available.
+	#
+	for SPARE in ${ZEVENT_VDEV_SPARE_PATHS}; do
+		set -- `vdev_status ${ZEVENT_POOL} ${SPARE}`
+		SPARE_VDEV_FOUND=$1
+		STATUS=$2
+		if [ "${STATUS}" = "AVAIL" ]; then
+			${ZPOOL} replace ${ZEVENT_POOL} \
+			    ${ZEVENT_VDEV_GUID} ${SPARE_VDEV_FOUND} && exit 0
+		fi
+	done
+
+	exit 1
+fi
+
+exit 4
diff --git a/cmd/zed/zed.d/zed.rc b/cmd/zed/zed.d/zed.rc
index 57c969c89900..69989f95315b 100644
--- a/cmd/zed/zed.d/zed.rc
+++ b/cmd/zed/zed.d/zed.rc
@@ -26,3 +26,9 @@
 
 # The syslog tag for marking zed events.
 #ZED_SYSLOG_TAG="zed"
+
+# Replace a device with a hot spare after N I/O errors are detected.
+#ZED_SPARE_ON_IO_ERRORS=1
+
+# Replace a device with a hot spare after N checksum errors are detected.
+#ZED_SPARE_ON_CHECKSUM_ERRORS=10
diff --git a/include/sys/fm/fs/zfs.h b/include/sys/fm/fs/zfs.h
index d9122ac5f7d3..d541b07a3729 100644
--- a/include/sys/fm/fs/zfs.h
+++ b/include/sys/fm/fs/zfs.h
@@ -75,6 +75,11 @@ extern "C" {
 #define	FM_EREPORT_PAYLOAD_ZFS_VDEV_ASHIFT	"vdev_ashift"
 #define	FM_EREPORT_PAYLOAD_ZFS_VDEV_COMP_TS	"vdev_complete_ts"
 #define	FM_EREPORT_PAYLOAD_ZFS_VDEV_DELTA_TS	"vdev_delta_ts"
+#define	FM_EREPORT_PAYLOAD_ZFS_VDEV_SPARE_PATHS	"vdev_spare_paths"
+#define	FM_EREPORT_PAYLOAD_ZFS_VDEV_SPARE_GUIDS	"vdev_spare_guids"
+#define	FM_EREPORT_PAYLOAD_ZFS_VDEV_READ_ERRORS	"vdev_read_errors"
+#define	FM_EREPORT_PAYLOAD_ZFS_VDEV_WRITE_ERRORS "vdev_write_errors"
+#define	FM_EREPORT_PAYLOAD_ZFS_VDEV_CKSUM_ERRORS "vdev_cksum_errors"
 #define	FM_EREPORT_PAYLOAD_ZFS_PARENT_GUID	"parent_guid"
 #define	FM_EREPORT_PAYLOAD_ZFS_PARENT_TYPE	"parent_type"
 #define	FM_EREPORT_PAYLOAD_ZFS_PARENT_PATH	"parent_path"
diff --git a/module/zfs/spa.c b/module/zfs/spa.c
index 9e7a7b785a32..af93b7ce5e11 100644
--- a/module/zfs/spa.c
+++ b/module/zfs/spa.c
@@ -1377,7 +1377,7 @@ spa_load_spares(spa_t *spa)
 	 * validate each vdev on the spare list.  If the vdev also exists in the
 	 * active configuration, then we also mark this vdev as an active spare.
 	 */
-	spa->spa_spares.sav_vdevs = kmem_alloc(nspares * sizeof (void *),
+	spa->spa_spares.sav_vdevs = kmem_zalloc(nspares * sizeof (void *),
 	    KM_PUSHPAGE);
 	for (i = 0; i < spa->spa_spares.sav_count; i++) {
 		VERIFY(spa_config_parse(spa, &vd, spares[i], NULL, 0,
diff --git a/module/zfs/zfs_fm.c b/module/zfs/zfs_fm.c
index df47d99cfafa..05ee84c19e4d 100644
--- a/module/zfs/zfs_fm.c
+++ b/module/zfs/zfs_fm.c
@@ -251,6 +251,11 @@ zfs_ereport_start(nvlist_t **ereport_out, nvlist_t **detector_out,
 	if (vd != NULL) {
 		vdev_t *pvd = vd->vdev_parent;
 		vdev_queue_t *vq = &vd->vdev_queue;
+		vdev_stat_t *vs = &vd->vdev_stat;
+		vdev_t *spare_vd;
+		uint64_t *spare_guids;
+		char **spare_paths;
+		int i, spare_count;
 
 		fm_payload_set(ereport, FM_EREPORT_PAYLOAD_ZFS_VDEV_GUID,
 		    DATA_TYPE_UINT64, vd->vdev_guid,
@@ -282,6 +287,16 @@ zfs_ereport_start(nvlist_t **ereport_out, nvlist_t **detector_out,
 			    DATA_TYPE_UINT64, vq->vq_io_delta_ts, NULL);
 		}
 
+		if (vs != NULL) {
+			fm_payload_set(ereport,
+			    FM_EREPORT_PAYLOAD_ZFS_VDEV_READ_ERRORS,
+			    DATA_TYPE_UINT64, vs->vs_read_errors,
+			    FM_EREPORT_PAYLOAD_ZFS_VDEV_WRITE_ERRORS,
+			    DATA_TYPE_UINT64, vs->vs_write_errors,
+			    FM_EREPORT_PAYLOAD_ZFS_VDEV_CKSUM_ERRORS,
+			    DATA_TYPE_UINT64, vs->vs_checksum_errors, NULL);
+		}
+
 		if (pvd != NULL) {
 			fm_payload_set(ereport,
 			    FM_EREPORT_PAYLOAD_ZFS_PARENT_GUID,
@@ -298,6 +313,28 @@ zfs_ereport_start(nvlist_t **ereport_out, nvlist_t **detector_out,
 				    FM_EREPORT_PAYLOAD_ZFS_PARENT_DEVID,
 				    DATA_TYPE_STRING, pvd->vdev_devid, NULL);
 		}
+
+		spare_count = spa->spa_spares.sav_count;
+		spare_paths = kmem_zalloc(sizeof (char *) * spare_count,
+		    KM_PUSHPAGE);
+		spare_guids = kmem_zalloc(sizeof (uint64_t) * spare_count,
+		    KM_PUSHPAGE);
+
+		for (i = 0; i < spare_count; i++) {
+			spare_vd = spa->spa_spares.sav_vdevs[i];
+			if (spare_vd) {
+				spare_paths[i] = spare_vd->vdev_path;
+				spare_guids[i] = spare_vd->vdev_guid;
+			}
+		}
+
+		fm_payload_set(ereport, FM_EREPORT_PAYLOAD_ZFS_VDEV_SPARE_PATHS,
+		    DATA_TYPE_STRING_ARRAY, spare_count, spare_paths,
+		    FM_EREPORT_PAYLOAD_ZFS_VDEV_SPARE_GUIDS,
+		    DATA_TYPE_UINT64_ARRAY, spare_count, spare_guids, NULL);
+
+		kmem_free(spare_guids, sizeof (uint64_t) * spare_count);
+		kmem_free(spare_paths, sizeof (char *) * spare_count);
 	}
 
 	if (zio != NULL) {
@@ -834,15 +871,18 @@ zfs_post_common(spa_t *spa, vdev_t *vd, const char *name)
 
 	(void) snprintf(class, sizeof (class), "%s.%s.%s", FM_RSRC_RESOURCE,
 	    ZFS_ERROR_CLASS, name);
-	VERIFY(nvlist_add_uint8(resource, FM_VERSION, FM_RSRC_VERSION) == 0);
-	VERIFY(nvlist_add_string(resource, FM_CLASS, class) == 0);
-	VERIFY(nvlist_add_uint64(resource,
-	    FM_EREPORT_PAYLOAD_ZFS_POOL_GUID, spa_guid(spa)) == 0);
+	VERIFY0(nvlist_add_uint8(resource, FM_VERSION, FM_RSRC_VERSION));
+	VERIFY0(nvlist_add_string(resource, FM_CLASS, class));
+	VERIFY0(nvlist_add_uint64(resource,
+	    FM_EREPORT_PAYLOAD_ZFS_POOL_GUID, spa_guid(spa)));
+	VERIFY0(nvlist_add_int32(resource,
+	    FM_EREPORT_PAYLOAD_ZFS_POOL_CONTEXT, spa_load_state(spa)));
+
 	if (vd) {
-		VERIFY(nvlist_add_uint64(resource,
-		    FM_EREPORT_PAYLOAD_ZFS_VDEV_GUID, vd->vdev_guid) == 0);
-		VERIFY(nvlist_add_uint64(resource,
-		    FM_EREPORT_PAYLOAD_ZFS_VDEV_STATE, vd->vdev_state) == 0);
+		VERIFY0(nvlist_add_uint64(resource,
+		    FM_EREPORT_PAYLOAD_ZFS_VDEV_GUID, vd->vdev_guid));
+		VERIFY0(nvlist_add_uint64(resource,
+		    FM_EREPORT_PAYLOAD_ZFS_VDEV_STATE, vd->vdev_state));
 	}
 
 	zfs_zevent_post(resource, NULL, zfs_zevent_post_cb);