| Current File : //usr/local/jetapps/usr/share/rear/layout/save/GNU/Linux/210_raid_layout.sh |
# Save the Software RAID layout
# Nothing to do when there is no /proc/mdstat
test -e /proc/mdstat || return 0
# Nothing to do when /proc/mdstat does not contain "blocks"
grep -q blocks /proc/mdstat || return 0
Log "Saving Software RAID configuration"
# Have 'mdadm --detail --scan --config=partitions' output as comment in disklayout.conf:
( echo "Software RAID devices (mdadm --detail --scan --config=partitions)" ; mdadm --detail --scan --config=partitions ) | grep -v '^$' | sed -e 's/^/# /' >>$DISKLAYOUT_FILE
local array raiddevice junk
local basename
local line
local metadata level raid_devices uuid name spare_devices layout chunksize component_devices container_size
local container array_size
local layout_option layout_option_name layout_option_value layout_option_setting
local component_device
local raid_layout_entry
local raid_dev_size raid_dev_label
local mdadm_exit_code
# Read 'mdadm --detail --scan --config=partitions' output which looks like
# ARRAY /dev/md/raid1sdab metadata=1.0 name=any:raid1sdab UUID=8d05eb84:2de831d1:dfed54b2:ad592118
# for a RAID1 array and for a RAID CONTAINER with IMSM metadata it looks like
# ARRAY /dev/md/imsm0 metadata=imsm UUID=4d5cf215:80024c95:e19fdff4:2fba35a8
# ARRAY /dev/md/Volume0_0 container=/dev/md/imsm0 member=0 UUID=ffb80762:127807b3:3d7e4f4d:4532022f
# cf. https://github.com/rear/rear/pull/2702#issuecomment-968904230
#
# For reasoning why
# COMMAND | while read ... do ... done
# is usually better than
# while read ... do ... done < <( COMMAND )
# see layout/save/GNU/Linux/220_lvm_layout.sh
mdadm --detail --scan --config=partitions | while read array raiddevice junk ; do
# Skip if it is not an "ARRAY":
test "$array" = "ARRAY" || continue
# 'raidarray' entries in disklayout.conf look like (cf. the 'mdadm --detail --scan --config=partitions' examples above)
# raidarray /dev/md127 metadata=1.0 level=raid1 raid-devices=2 uuid=8d05eb84:2de831d1:dfed54b2:ad592118 name=raid1sdab devices=/dev/sda,/dev/sdb
# for a RAID1 array and for a RAID CONTAINER with IMSM metadata it looks like
# raidarray /dev/md127 metadata=imsm level=container raid-devices=2 uuid=4d5cf215:80024c95:e19fdff4:2fba35a8 name=imsm0 devices=/dev/sda,/dev/sdb
# raidarray /dev/md126 level=raid1 raid-devices=2 uuid=ffb80762:127807b3:3d7e4f4d:4532022f name=Volume0_0 devices=/dev/md127 size=390706176
# cf. https://github.com/rear/rear/pull/2702#issuecomment-968904230
# Each 'raidarray' entry in disklayout.conf starts with the keyword 'raidarray':
raid_layout_entry="raidarray"
# Do not use an array name from a previous run of the while loop:
name=""
basename=${raiddevice##*/}
# When raiddevice is a symlink like /dev/md/raid1sdab -> /dev/md127
# Use the kernel device node and set the array name to the symlink's basename:
if test -h $raiddevice ; then
raiddevice=$( readlink -e $raiddevice )
name=$basename
fi
test -b "$raiddevice" && raid_layout_entry+=" $raiddevice" || Error "RAID device '$raiddevice' is no block device"
# We use the detailed mdadm output quite a lot so run the mdadm command only once:
mdadm_details="$TMP_DIR/mdraid.$basename"
mdadm --misc --detail $raiddevice | grep -v '^$' > $mdadm_details
# Have 'mdadm --misc --detail $raiddevice' output as comment in disklayout.conf:
( echo "Software RAID $name device $raiddevice (mdadm --misc --detail $raiddevice)" ; cat $mdadm_details ) | sed -e 's/^/# /' >>$DISKLAYOUT_FILE
# Example 'mdadm --misc --detail $raiddevice' output for a RAID1 array:
#
# /dev/md/raid1sdab:
# Version : 1.0
# Creation Time : Wed Oct 13 13:17:13 2021
# Raid Level : raid1
# Array Size : 12582784 (12.00 GiB 12.88 GB)
# Used Dev Size : 12582784 (12.00 GiB 12.88 GB)
# Raid Devices : 2
# Total Devices : 2
# Persistence : Superblock is persistent
# Intent Bitmap : Internal
# Update Time : Tue Nov 16 11:06:16 2021
# State : clean
# Active Devices : 2
# Working Devices : 2
# Failed Devices : 0
# Spare Devices : 0
# Consistency Policy : bitmap
# Name : any:raid1sdab
# UUID : 8d05eb84:2de831d1:dfed54b2:ad592118
# Events : 216
# Number Major Minor RaidDevice State
# 0 8 0 0 active sync /dev/sda
# 1 8 16 1 active sync /dev/sdb
#
# Example 'mdadm --misc --detail $raiddevice' output for a RAID CONTAINER with IMSM metadata
# cf. https://github.com/rear/rear/pull/2702#issuecomment-968904230
# /dev/md127:
# Version : imsm
# Raid Level : container
# Total Devices : 2
# Working Devices : 2
# UUID : 4d5cf215:80024c95:e19fdff4:2fba35a8
# Member Arrays : /dev/md/Volume0_0
# Number Major Minor RaidDevice
# - 8 0 - /dev/sda
# - 8 16 - /dev/sdb
#
# /dev/md126:
# Container : /dev/md/imsm0, member 0
# Raid Level : raid1
# Array Size : 390706176 (372.61 GiB 400.08 GB)
# Used Dev Size : 390706176 (372.61 GiB 400.08 GB)
# Raid Devices : 2
# Total Devices : 2
# State : active
# Active Devices : 2
# Working Devices : 2
# Failed Devices : 0
# Consistency Policy : resync
# UUID : ffb80762:127807b3:3d7e4f4d:4532022f
# Number Major Minor RaidDevice State
# 1 8 16 0 active sync /dev/sdb
# 0 8 0 1 active sync /dev/sda
# doc/user-guide/06-layout-configuration.adoc reads
# Disk layout file syntax
# Software RAID
# raidarray /dev/<kernel RAID device> level=<RAID level> raid-devices=<nr of active devices> devices=<component device1,component device2,...> [name=<array name>] [metadata=<metadata style>] [uuid=<UUID>] [layout=<data layout>] [chunk=<chunk size>] [spare-devices=<nr of spare devices>] [size=<container size>]
# so the mdadm options --level --raid-devices and the component-devices are mandatory:
line=( $( grep "Raid Level :" $mdadm_details ) )
level=${line[3]}
# A RAID level that is more than one word would make 'read' fail for this 'raidarray' entry in disklayout.conf
test $level || Error "RAID $raiddevice level '$level' is not a single word"
raid_layout_entry+=" level=$level"
line=( $( grep "Raid Devices :" $mdadm_details ) )
raid_devices=${line[3]}
line=( $( grep "Total Devices :" $mdadm_details ) )
total_devices=${line[3]}
if test $raid_devices && test $raid_devices -gt 0 ; then
raid_layout_entry+=" raid-devices=$raid_devices"
elif test $total_devices && test $total_devices -gt 0 ; then
raid_layout_entry+=" raid-devices=$total_devices"
else
Error "Neither number of active devices nor number of total devices is greater than 0 for RAID $raiddevice"
fi
container=$( grep "Container" $mdadm_details | tr -d " " | cut -d ":" -f "2" | cut -d "," -f "1")
line=( $( grep "Used Dev Size :" $mdadm_details ) )
used_dev_size=${line[4]}
line=( $( grep "Array Size :" $mdadm_details ) )
array_size=${line[3]}
if test "$container" ; then
component_devices=" devices=$( readlink -e $container )"
if test "$used_dev_size" ; then
container_size=$used_dev_size
elif test "$array_size" ; then
container_size=$(( array_size / raid_devices ))
fi
else
# Find all component devices
# use the output of mdadm, but skip the array itself that is e.g. /dev/md127 or /dev/md/raid1sdab
# sysfs has the information in RHEL 5+, but RHEL 4 lacks it.
component_devices=""
for component_device in $( grep -o '/dev/.*' $mdadm_details | grep -v '/dev/md' | tr "\n" " " ) ; do
component_device=$( get_device_name $component_device )
test -b "$component_device" || Error "RAID $raiddevice component device '$component_device' is no block device"
# A component device that is more than one word would make 'read' fail for this 'raidarray' entry in disklayout.conf
test $component_device || Error "RAID $raiddevice component device '$component_device' is not a single word"
# Have the component devices string as "first_component_device,second_component_device,..."
test $component_devices && component_devices+=",$component_device" || component_devices="$component_device"
done
fi
test $component_devices && raid_layout_entry+=" devices=$component_devices" || Error "No component devices for RAID $raiddevice"
# Optional mdadm option settings:
test $name && raid_layout_entry+=" name=$name"
line=( $( grep "Version :" $mdadm_details ) )
metadata=${line[2]}
test $metadata && raid_layout_entry+=" metadata=$metadata"
line=( $( grep "UUID :" $mdadm_details ) )
uuid=${line[2]}
test $uuid && raid_layout_entry+=" uuid=$uuid"
# A "Layout :" line in the detailed mdadm output normally looks like
# Layout : near=2
# Layout : far=3
# Layout : offset=4
# cf. https://github.com/rear/rear/pull/2768#issuecomment-1072362485
# and https://github.com/rear/rear/pull/2768#issuecomment-1072361069
# but it might also look like
# Layout : near=2, far=3
# or it might even look like (regardless that this was never seen in practice)
# Layout : near=2, far=3, offset=4
# cf. https://linux-blog.anracom.com/tag/far-layout/
# and https://unix.stackexchange.com/questions/280283/is-it-possible-to-create-a-mdadm-raid10-with-both-near-and-far-layout-options
# and https://ubuntuforums.org/showthread.php?t=1689828&page=4
# For the above examples the line array becomes ("declare -p line" outputs):
# declare -a line=([0]="Layout" [1]=":" [2]="near=2")
# declare -a line=([0]="Layout" [1]=":" [2]="far=3")
# declare -a line=([0]="Layout" [1]=":" [2]="offset=4")
# declare -a line=([0]="Layout" [1]=":" [2]="near=2," [3]="far=3")
# declare -a line=([0]="Layout" [1]=":" [2]="near=2," [3]="far=3," [4]="offset=4")
line=( $( grep "Layout :" $mdadm_details ) )
# We use ${line[3]:-} and ${line[4]:-} to be safe against things like
# "bash: line[3]: unbound variable" in case of 'set -eu'
# so for the above examples the layout string becomes:
# near=2
# far=3
# offset=4
# near=2,far=3
# near=2,far=3,offset=4
layout="${line[2]}${line[3]:-}${line[4]:-}"
# For RAID10 have the layout value what the mdadm command needs as --layout option value
# so with the above examples the mdadm command option --layout=... value has to become
# near=2 -> n2
# far=3 -> f3
# offset=4 -> o4
# near=2,far=3 -> n2
# near=2,far=3,offset=4 -> n2
# TODO: Currently if there is more than one RAID10 layout value only the first one is used because according to
# https://unix.stackexchange.com/questions/280283/is-it-possible-to-create-a-mdadm-raid10-with-both-near-and-far-layout-options
# it seems it is not possible (or it does not make sense in practice) to set both "near=..." and "far=..."
# and we also assume it is not possible (or it does not make sense in practice) to set more than one RAID10 layout value.
if test "$level" = "raid10" ; then
layout_option_setting=""
OIFS=$IFS
IFS=","
for layout_option in $layout ; do
# When a RAID10 layout option is already set for this RAID array an additional one is not supported:
if test $layout_option_setting ; then
LogPrintError "Ignoring additional RAID10 layout '$layout_option' for $raiddevice (only one RAID10 layout setting is supported)"
continue
fi
layout_option_name=${layout_option%=*}
layout_option_value=${layout_option#*=}
# The RAID10 layout option value must be "a small number" where "2 is normal, 3 can be useful"
# according to "man mdadm" (of mdadm v4.1 in openSUSE Leap 15.3).
# This test also fails when the RAID10 layout option value is not a number:
if ! test $layout_option_value -gt 0 ; then
LogPrintError "Ignoring RAID10 layout '$layout_option' for $raiddevice (the value is not at least 1)"
continue
fi
# Now the RAID10 layout option value is at least a number:
if ! test $layout_option_value -le 9 ; then
LogPrintError "Ignoring RAID10 layout '$layout_option' for $raiddevice (the value is not a small number)"
continue
fi
# Save the RAID10 layout option with the right syntax for the mdadm --layout option value during "rear recover":
case "$layout_option_name" in
(near)
layout_option_setting="n$layout_option_value"
;;
(far)
layout_option_setting="f$layout_option_value"
;;
(offset)
layout_option_setting="o$layout_option_value"
;;
(*)
LogPrintError "Ignoring RAID10 layout '$layout_option' for $raiddevice (only 'near' 'far' and 'offset' are valid)"
;;
esac
done
IFS=$OIFS
# Ensure $layout_option_setting is a single non empty and non blank word
# (no quoting because test " " returns zero exit code):
test $layout_option_setting && layout="$layout_option_setting" || layout=""
fi
# mdadm can print '-unknown-' for a RAID layout
# which got recently (2019-12-02) added to RAID0 (it existed before for RAID5 and RAID6 and RAID10) see
# https://git.kernel.org/pub/scm/utils/mdadm/mdadm.git/commit/Detail.c?id=329dfc28debb58ffe7bd1967cea00fc583139aca
# so we treat '-unknown-' same as an empty value to avoid that layout/prepare/GNU/Linux/120_include_raid_code.sh
# will create a 'mdadm' command in diskrestore.sh like "mdadm ... --layout=-unknown- ..." which would fail
# during "rear recover" with something like "mdadm: layout -unknown- not understood for raid0"
# see https://github.com/rear/rear/issues/2616
# and ensure $layout is a single non empty and non blank word
# (no quoting because test " " returns zero exit code)
# and 'test ... && test ...' instead of 'test ... -a ...' to avoid a bash error message
# because when $layout is blank or empty test $layout -a '-unknown-' != "$layout"
# becomes test -a '-unknown-' != ""
# which results "bash: test: too many arguments"
# cf. https://github.com/rear/rear/pull/2768#discussion_r843740413
test $layout && test '-unknown-' != "$layout" && raid_layout_entry+=" layout=$layout"
chunksize=$( grep "Chunk Size" $mdadm_details | tr -d " " | cut -d ":" -f "2" | sed -r 's/^([0-9]+).+/\1/')
test $chunksize && raid_layout_entry+=" chunk=$chunksize"
spare_devices=""
test $raid_devices && spare_devices=$(( total_devices - raid_devices ))
test $spare_devices -gt 0 && raid_layout_entry+=" spare-devices=$spare_devices"
test $container_size -gt 0 && raid_layout_entry+=" size=$container_size"
echo "# RAID device $raiddevice" >>$DISKLAYOUT_FILE
echo "# Format: raidarray /dev/<kernel RAID device> level=<RAID level> raid-devices=<nr of active devices> devices=<component device1,component device2,...> [name=<array name>] [metadata=<metadata style>] [uuid=<UUID>] [layout=<data layout>] [chunk=<chunk size>] [spare-devices=<nr of spare devices>] [size=<container size>]" >>$DISKLAYOUT_FILE
echo "$raid_layout_entry" >>$DISKLAYOUT_FILE
# cf. the code in layout/save/GNU/Linux/200_partition_layout.sh
# $raiddevice is e.g. /dev/md127
raid_dev_size=$( get_disk_size ${raiddevice#/dev/} )
raid_dev_label=$( parted -s $raiddevice print | grep -E "Partition Table|Disk label" | cut -d ":" -f "2" | tr -d " " )
echo "# RAID disk $raiddevice" >>$DISKLAYOUT_FILE
echo "# Format: raiddisk <devname> <size(bytes)> <partition label type>" >>$DISKLAYOUT_FILE
echo "raiddisk $raiddevice $raid_dev_size $raid_dev_label" >>$DISKLAYOUT_FILE
# extract_partitions is run as a separated process (in a subshell)
# because it runs in the "mdadm ... | while read ... ; do ... done" pipe
# so things only work here if extract_partitions does not set variables
# that are meant to be used outside of this pipe, check extract_partitions()
# in layout/save/GNU/Linux/200_partition_layout.sh
echo "# Partitions on $raiddevice" >>$DISKLAYOUT_FILE
echo "# Format: part <device> <partition size(bytes)> <partition start(bytes)> <partition type|name> <flags> /dev/<partition>" >>$DISKLAYOUT_FILE
extract_partitions "$raiddevice" >>$DISKLAYOUT_FILE
done
# Check the exit code of "mdadm --detail --scan --config=partitions"
# in the "mdadm --detail --scan --config=partitions | while read ... ; do ... done" pipe
# cf. layout/save/GNU/Linux/220_lvm_layout.sh
mdadm_exit_code=${PIPESTATUS[0]}
test $mdadm_exit_code -eq 0 || Error "'mdadm --detail --scan --config=partitions' failed with exit code $mdadm_exit_code"
# mdadm is required in the recovery system if disklayout.conf contains at least one 'raidarray' entry
# see the create_raidarray function in layout/prepare/GNU/Linux/120_include_raid_code.sh
# what program calls are written to diskrestore.sh
# cf. https://github.com/rear/rear/issues/1963
if grep -q '^raidarray ' $DISKLAYOUT_FILE ; then
REQUIRED_PROGS+=( mdadm )
# mdmon was added via https://github.com/rear/rear/pull/2702
PROGS+=( mdmon )
fi