Imported Upstream version 0.6.4.2

[mirror_zfs-debian.git] / cmd / zed / zed.d / checksum-spare.sh

diff --git a/cmd/zed/zed.d/checksum-spare.sh b/cmd/zed/zed.d/checksum-spare.sh
new file mode 100755 (executable)
index 0000000..b64b2a9
--- /dev/null
+++ b/cmd/zed/zed.d/checksum-spare.sh
@@ -0,0 +1,126 @@
+#!/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 "${ZED_ZEDLET_DIR}/zed.rc" && . "${ZED_ZEDLET_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`
+       local T='       '       # tab character since '\t' isn't portable
+
+       ${ZPOOL} status ${POOL} | sed -n -e \
+           "s,^[ $T]*\(.*$VDEV\(-part[0-9]\+\)\?\)[ $T]*\([A-Z]\+\).*,\1 \3,p"
+       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