mirror_zfs/cmd/zed/zed.d/io-spare.sh
Chris Dunlap 090b19158a Add notification to io-spare.sh
The io-spare.sh ZEDLET does not generate a notification when a failing
device is replaced with a hot spare.  Maybe it should tell someone.

This commit adds a notification message to the io-spare.sh ZEDLET.
This notification is triggered when a failing device is successfully
replaced with a hot spare after encountering a checksum or io error.

Signed-off-by: Chris Dunlap <cdunlap@llnl.gov>
2015-04-27 12:08:08 -07:00

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#!/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: hot spare replacement successful
# 1: hot spare device not available
# 2: hot sparing disabled or threshold not reached
# 3: device already faulted or degraded
# 9: internal error
[ -f "${ZED_ZEDLET_DIR}/zed.rc" ] && . "${ZED_ZEDLET_DIR}/zed.rc"
. "${ZED_ZEDLET_DIR}/zed-functions.sh"
# Disabled by default. Enable in the zed.rc file.
: "${ZED_SPARE_ON_CHECKSUM_ERRORS:=0}"
: "${ZED_SPARE_ON_IO_ERRORS:=0}"
# query_vdev_status (pool, vdev)
#
# Given a [pool] and [vdev], return the matching vdev path & status on stdout.
#
# Warning: This function does not handle the case of [pool] or [vdev]
# containing whitespace. Beware of ShellCheck SC2046. Caveat emptor.
#
# Arguments
# pool: pool name
# vdev: virtual device name
#
# StdOut
# arg1: vdev pathname
# arg2: vdev status
#
query_vdev_status()
{
local pool="$1"
local vdev="$2"
local t
vdev="$(basename -- "${vdev}")"
([ -n "${pool}" ] && [ -n "${vdev}" ]) || return
t="$(printf '\t')"
"${ZPOOL}" status "${pool}" 2>/dev/null | sed -n -e \
"s,^[ $t]*\(.*${vdev}\(-part[0-9]\+\)\?\)[ $t]*\([A-Z]\+\).*,\1 \3,p" \
| tail -1
}
# notify (old_vdev, new_vdev, num_errors)
#
# Send a notification regarding the hot spare replacement.
#
# Arguments
# old_vdev: path of old vdev that has failed
# new_vdev: path of new vdev used as the hot spare replacement
# num_errors: number of errors that triggered this replacement
#
notify()
{
local old_vdev="$1"
local new_vdev="$2"
local num_errors="$3"
local note_subject
local note_pathname
local s
local rv
umask 077
note_subject="ZFS hot spare replacement for ${ZEVENT_POOL} on $(hostname)"
note_pathname="${TMPDIR:="/tmp"}/$(basename -- "$0").${ZEVENT_EID}.$$"
{
[ "${num_errors}" -ne 1 ] 2>/dev/null && s="s"
echo "ZFS has replaced a failing device with a hot spare after" \
"${num_errors} ${ZEVENT_SUBCLASS} error${s}:"
echo
echo " eid: ${ZEVENT_EID}"
echo " class: ${ZEVENT_SUBCLASS}"
echo " host: $(hostname)"
echo " time: ${ZEVENT_TIME_STRING}"
echo " old: ${old_vdev}"
echo " new: ${new_vdev}"
"${ZPOOL}" status "${ZEVENT_POOL}"
} > "${note_pathname}"
zed_notify "${note_subject}" "${note_pathname}"; rv=$?
rm -f "${note_pathname}"
return "${rv}"
}
# main
#
# Arguments
# none
#
# Return
# see above
#
main()
{
local num_errors
local action
local lockfile
local vdev_path
local vdev_status
local spare
local spare_path
local spare_status
local zpool_err
local zpool_rv
local rv
# Avoid hot-sparing a hot-spare.
#
# Note: ZEVENT_VDEV_PATH is not defined for ZEVENT_VDEV_TYPE=spare.
#
[ "${ZEVENT_VDEV_TYPE}" = "spare" ] && exit 2
[ -n "${ZEVENT_POOL}" ] || exit 9
[ -n "${ZEVENT_VDEV_GUID}" ] || exit 9
[ -n "${ZEVENT_VDEV_PATH}" ] || exit 9
zed_check_cmd "${ZPOOL}" "${ZINJECT}" || exit 9
# Fault the device after a given number of I/O errors.
#
if [ "${ZEVENT_SUBCLASS}" = "io" ]; then
if [ "${ZED_SPARE_ON_IO_ERRORS}" -gt 0 ]; then
num_errors=$((ZEVENT_VDEV_READ_ERRORS + ZEVENT_VDEV_WRITE_ERRORS))
[ "${num_errors}" -ge "${ZED_SPARE_ON_IO_ERRORS}" ] \
&& action="fault"
fi 2>/dev/null
# Degrade the device after a given number of checksum errors.
#
elif [ "${ZEVENT_SUBCLASS}" = "checksum" ]; then
if [ "${ZED_SPARE_ON_CHECKSUM_ERRORS}" -gt 0 ]; then
num_errors="${ZEVENT_VDEV_CKSUM_ERRORS}"
[ "${num_errors}" -ge "${ZED_SPARE_ON_CHECKSUM_ERRORS}" ] \
&& action="degrade"
fi 2>/dev/null
else
zed_log_err "unsupported event class \"${ZEVENT_SUBCLASS}\""
exit 9
fi
# Error threshold not reached.
#
if [ -z "${action}" ]; then
exit 2
fi
lockfile="zed.spare.lock"
zed_lock "${lockfile}"
# shellcheck disable=SC2046
set -- $(query_vdev_status "${ZEVENT_POOL}" "${ZEVENT_VDEV_PATH}")
vdev_path="$1"
vdev_status="$2"
# Device is already FAULTED or DEGRADED.
#
if [ "${vdev_status}" = "FAULTED" ] \
|| [ "${vdev_status}" = "DEGRADED" ]; then
rv=3
else
rv=1
# 1) FAULT or DEGRADE the device.
#
"${ZINJECT}" -d "${ZEVENT_VDEV_GUID}" -A "${action}" "${ZEVENT_POOL}"
# 2) Set the SES fault beacon.
#
# TODO: 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
# 3) Replace the device with a hot spare.
#
# Round-robin through the spares trying those that are available.
#
for spare in ${ZEVENT_VDEV_SPARE_PATHS}; do
# shellcheck disable=SC2046
set -- $(query_vdev_status "${ZEVENT_POOL}" "${spare}")
spare_path="$1"
spare_status="$2"
[ "${spare_status}" = "AVAIL" ] || continue
zpool_err="$("${ZPOOL}" replace "${ZEVENT_POOL}" \
"${ZEVENT_VDEV_GUID}" "${spare_path}" 2>&1)"; zpool_rv=$?
if [ "${zpool_rv}" -ne 0 ]; then
[ -n "${zpool_err}" ] && zed_log_err "zpool ${zpool_err}"
else
notify "${vdev_path}" "${spare_path}" "${num_errors}"
rv=0
break
fi
done
fi
zed_unlock "${lockfile}"
exit "${rv}"
}
main "$@"