zfs/cmd/vdev_id/vdev_id

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#!/bin/sh
#
# vdev_id: udev helper to generate user-friendly names for JBOD disks
#
# This script parses the file /etc/zfs/vdev_id.conf to map a
# physical path in a storage topology to a channel name. The
# channel name is combined with a disk enclosure slot number to
# create an alias that reflects the physical location of the drive.
# This is particularly helpful when it comes to tasks like replacing
# failed drives. Slot numbers may also be re-mapped in case the
# default numbering is unsatisfactory. The drive aliases will be
# created as symbolic links in /dev/disk/by-vdev.
#
# The currently supported topologies are sas_direct and sas_switch.
# A multipath mode is supported in which dm-mpath devices are
# handled by examining the first-listed running component disk. In
# multipath mode the configuration file should contain a channel
# definition with the same name for each path to a given enclosure.
#
# The alias keyword provides a simple way to map already-existing
# device symlinks to more convenient names. It is suitable for
# small, static configurations or for sites that have some automated
# way to generate the mapping file.
#
#
# Some example configuration files are given below.
# #
# # Example vdev_id.conf - sas_direct.
# #
#
# multipath no
# topology sas_direct
# phys_per_port 4
#
# # PCI_ID HBA PORT CHANNEL NAME
# channel 85:00.0 1 A
# channel 85:00.0 0 B
# channel 86:00.0 1 C
# channel 86:00.0 0 D
#
# # Custom mapping for Channel A
#
# # Linux Mapped
# # Slot Slot Channel
# slot 1 7 A
# slot 2 10 A
# slot 3 3 A
# slot 4 6 A
#
# # Default mapping for B, C, and D
# slot 1 4
# slot 2 2
# slot 3 1
# slot 4 3
# #
# # Example vdev_id.conf - sas_switch
# #
#
# topology sas_switch
#
# # SWITCH PORT CHANNEL NAME
# channel 1 A
# channel 2 B
# channel 3 C
# channel 4 D
# #
# # Example vdev_id.conf - multipath
# #
#
# multipath yes
#
# # PCI_ID HBA PORT CHANNEL NAME
# channel 85:00.0 1 A
# channel 85:00.0 0 B
# channel 86:00.0 1 A
# channel 86:00.0 0 B
# #
# # Example vdev_id.conf - alias
# #
#
# # by-vdev
# # name fully qualified or base name of device link
# alias d1 /dev/disk/by-id/wwn-0x5000c5002de3b9ca
# alias d2 wwn-0x5000c5002def789e
PATH=/bin:/sbin:/usr/bin:/usr/sbin
CONFIG=/etc/zfs/vdev_id.conf
PHYS_PER_PORT=
DEV=
MULTIPATH=
TOPOLOGY=
usage() {
cat << EOF
Usage: vdev_id [-h]
vdev_id <-d device> [-c config_file] [-p phys_per_port]
[-g sas_direct|sas_switch] [-m]
-c specify name of alernate config file [default=$CONFIG]
-d specify basename of device (i.e. sda)
-g Storage network topology [default="$TOPOLOGY"]
-m Run in multipath mode
-p number of phy's per switch port [default=$PHYS_PER_PORT]
-h show this summary
EOF
exit 0
}
map_slot() {
local LINUX_SLOT=$1
local CHANNEL=$2
local MAPPED_SLOT=
MAPPED_SLOT=`awk "\\$1 == \"slot\" && \\$2 == ${LINUX_SLOT} && \
\\$4 ~ /^${CHANNEL}$|^$/ { print \\$3; exit }" $CONFIG`
if [ -z "$MAPPED_SLOT" ] ; then
MAPPED_SLOT=$LINUX_SLOT
fi
printf "%d" ${MAPPED_SLOT}
}
map_channel() {
local MAPPED_CHAN=
local PCI_ID=$1
local PORT=$2
case $TOPOLOGY in
"sas_switch")
MAPPED_CHAN=`awk "\\$1 == \"channel\" && \\$2 == ${PORT} \
{ print \\$3; exit }" $CONFIG`
;;
"sas_direct")
MAPPED_CHAN=`awk "\\$1 == \"channel\" && \
\\$2 == \"${PCI_ID}\" && \\$3 == ${PORT} \
{ print \\$4; exit }" $CONFIG`
;;
esac
printf "%s" ${MAPPED_CHAN}
}
sas_handler() {
if [ -z "$PHYS_PER_PORT" ] ; then
PHYS_PER_PORT=`awk "\\$1 == \"phys_per_port\" \
{print \\$2; exit}" $CONFIG`
fi
PHYS_PER_PORT=${PHYS_PER_PORT:-4}
if ! echo $PHYS_PER_PORT | grep -q -E '^[0-9]+$' ; then
echo "Error: phys_per_port value $PHYS_PER_PORT is non-numeric"
exit 1
fi
if [ -z "$MULTIPATH_MODE" ] ; then
MULTIPATH_MODE=`awk "\\$1 == \"multipath\" \
{print \\$2; exit}" $CONFIG`
fi
# Use first running component device if we're handling a dm-mpath device
if [ "$MULTIPATH_MODE" = "yes" ] ; then
# If udev didn't tell us the UUID via DM_NAME, check /dev/mapper
if [ -z "$DM_NAME" ] ; then
DM_NAME=`ls -l --full-time /dev/mapper |
awk "/\/$DEV$/{print \\$9}"`
fi
# For raw disks udev exports DEVTYPE=partition when
# handling partitions, and the rules can be written to
# take advantage of this to append a -part suffix. For
# dm devices we get DEVTYPE=disk even for partitions so
# we have to append the -part suffix directly in the
# helper.
if [ "$DEVTYPE" != "partition" ] ; then
PART=`echo $DM_NAME | awk -Fp '/p/{print "-part"$2}'`
fi
# Strip off partition information.
DM_NAME=`echo $DM_NAME | sed 's/p[0-9][0-9]*$//'`
if [ -z "$DM_NAME" ] ; then
return
fi
# Get the raw scsi device name from multipath -l. Strip off
# leading pipe symbols to make field numbering consistent.
DEV=`multipath -l $DM_NAME |
awk '/running/{gsub("^[|]"," "); print $3 ; exit}'`
if [ -z "$DEV" ] ; then
return
fi
fi
if echo $DEV | grep -q ^/devices/ ; then
sys_path=$DEV
else
sys_path=`udevadm info -q path -p /sys/block/$DEV 2>/dev/null`
fi
# Use positional parameters as an ad-hoc array
set -- $(echo "$sys_path" | tr / ' ')
num_dirs=$#
scsi_host_dir="/sys"
# Get path up to /sys/.../hostX
i=1
while [ $i -le $num_dirs ] ; do
d=$(eval echo \${$i})
scsi_host_dir="$scsi_host_dir/$d"
echo $d | grep -q -E '^host[0-9]+$' && break
i=$(($i + 1))
done
if [ $i = $num_dirs ] ; then
return
fi
PCI_ID=$(eval echo \${$(($i -1))} | awk -F: '{print $2":"$3}')
# In sas_switch mode, the directory four levels beneath
# /sys/.../hostX contains symlinks to phy devices that reveal
# the switch port number. In sas_direct mode, the phy links one
# directory down reveal the HBA port.
port_dir=$scsi_host_dir
case $TOPOLOGY in
"sas_switch") j=$(($i + 4)) ;;
"sas_direct") j=$(($i + 1)) ;;
esac
i=$(($i + 1))
while [ $i -le $j ] ; do
port_dir="$port_dir/$(eval echo \${$i})"
i=$(($i + 1))
done
PHY=`ls -d $port_dir/phy* 2>/dev/null | head -1 | awk -F: '{print $NF}'`
if [ -z "$PHY" ] ; then
return
fi
PORT=$(( $PHY / $PHYS_PER_PORT ))
# Look in /sys/.../sas_device/end_device-X for the bay_identifier
# attribute.
end_device_dir=$port_dir
while [ $i -lt $num_dirs ] ; do
d=$(eval echo \${$i})
end_device_dir="$end_device_dir/$d"
if echo $d | grep -q '^end_device' ; then
end_device_dir="$end_device_dir/sas_device/$d"
break
fi
i=$(($i + 1))
done
SLOT=`cat $end_device_dir/bay_identifier 2>/dev/null`
if [ -z "$SLOT" ] ; then
return
fi
CHAN=`map_channel $PCI_ID $PORT`
SLOT=`map_slot $SLOT $CHAN`
if [ -z "$CHAN" ] ; then
return
fi
echo ${CHAN}${SLOT}${PART}
}
alias_handler () {
# Special handling is needed to correctly append a -part suffix
# to partitions of device mapper devices. The DEVTYPE attribute
# is normally set to "disk" instead of "partition" in this case,
# so the udev rules won't handle that for us as they do for
# "plain" block devices.
#
# For example, we may have the following links for a device and its
# partitions,
#
# /dev/disk/by-id/dm-name-isw_dibgbfcije_ARRAY0 -> ../../dm-0
# /dev/disk/by-id/dm-name-isw_dibgbfcije_ARRAY0p1 -> ../../dm-1
# /dev/disk/by-id/dm-name-isw_dibgbfcije_ARRAY0p2 -> ../../dm-3
#
# and the following alias in vdev_id.conf.
#
# alias A0 dm-name-isw_dibgbfcije_ARRAY0
#
# The desired outcome is for the following links to be created
# without having explicitly defined aliases for the partitions.
#
# /dev/disk/by-vdev/A0 -> ../../dm-0
# /dev/disk/by-vdev/A0-part1 -> ../../dm-1
# /dev/disk/by-vdev/A0-part2 -> ../../dm-3
#
# Warning: The following grep pattern will misidentify whole-disk
# devices whose names end with 'p' followed by a string of
# digits as partitions, causing alias creation to fail. This
# ambiguity seems unavoidable, so devices using this facility
# must not use such names.
local DM_PART=
if echo $DM_NAME | grep -q -E 'p[0-9][0-9]*$' ; then
if [ "$DEVTYPE" != "partition" ] ; then
DM_PART=`echo $DM_NAME | awk -Fp '/p/{print "-part"$2}'`
fi
fi
# DEVLINKS attribute must have been populated by already-run udev rules.
for link in $DEVLINKS ; do
# Remove partition information to match key of top-level device.
if [ -n "$DM_PART" ] ; then
link=`echo $link | sed 's/p[0-9][0-9]*$//'`
fi
# Check both the fully qualified and the base name of link.
for l in $link `basename $link` ; do
alias=`awk "\\$1 == \"alias\" && \\$3 == \"${l}\" \
{ print \\$2; exit }" $CONFIG`
if [ -n "$alias" ] ; then
echo ${alias}${DM_PART}
return
fi
done
done
}
while getopts 'c:d:g:mp:h' OPTION; do
case ${OPTION} in
c)
CONFIG=${OPTARG}
;;
d)
DEV=${OPTARG}
;;
g)
TOPOLOGY=$OPTARG
;;
p)
PHYS_PER_PORT=${OPTARG}
;;
m)
MULTIPATH_MODE=yes
;;
h)
usage
;;
esac
done
if [ ! -r $CONFIG ] ; then
exit 0
fi
if [ -z "$DEV" ] ; then
echo "Error: missing required option -d"
exit 1
fi
if [ -z "$TOPOLOGY" ] ; then
TOPOLOGY=`awk "\\$1 == \"topology\" {print \\$2; exit}" $CONFIG`
fi
# First check if an alias was defined for this device.
ID_VDEV=`alias_handler`
if [ -z "$ID_VDEV" ] ; then
TOPOLOGY=${TOPOLOGY:-sas_direct}
case $TOPOLOGY in
sas_direct|sas_switch)
ID_VDEV=`sas_handler`
;;
*)
echo "Error: unknown topology $TOPOLOGY"
exit 1
;;
esac
fi
if [ -n "$ID_VDEV" ] ; then
echo "ID_VDEV=${ID_VDEV}"
echo "ID_VDEV_PATH=disk/by-vdev/${ID_VDEV}"
fi