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jueves, 21 de julio de 2011

Reescanear LUNs en Linux con HBA Qlogic

Buenas de nuevo... como veo que lo tengo abandonado el blog y "genero" mucha informacion tecnica que creo que seria interesante publicar en algun lado... voy a ir intercalandola con las fricadas que vaya colgando... asi que bueno este sera el primer Post de muchos...

Hace poco me he encontrado en la tesitura de que tenia un Ubuntu Server 11.04 con unas HBA (tarjetas de fibra) al que se le presentabas LUNS y para "verlas" tenia que reiniciar el sistema... asi que en una busqueda rapida por internet he encontrado una solucion mas elegante... si tienes la combinacion con tarjetas Qlogic... esto lo puedes averiguar rapidamente con este comando:

vmfs-bck:~$ lspci | grep QLogic
0a:00.0 Fibre Channel: QLogic Corp. ISP2432-based 4Gb Fibre Channel to PCI Express HBA (rev 03)
0b:00.0 Fibre Channel: QLogic Corp. ISP2432-based 4Gb Fibre Channel to PCI Express HBA (rev 03)
21:00.0 Fibre Channel: QLogic Corp. ISP2432-based 4Gb Fibre Channel to PCI Express HBA (rev 02)
22:00.0 Fibre Channel: QLogic Corp. ISP2432-based 4Gb Fibre Channel to PCI Express HBA (rev 02)

Una vez comprobado esto podremos pasar el siguiente Script a la maquina :




#!/bin/bash
# Skript to rescan SCSI bus, using the
# scsi add-single-device mechanism
# (w) 1998-03-19 Kurt Garloff (c) GNU GPL
# (w) 2003-07-16 Kurt Garloff (c) GNU GPL
# $Id: rescan-scsi-bus.sh,v 1.15 2004/05/08 14:47:13 garloff Exp $

setcolor ()
{
red="\e[0;31m"
green="\e[0;32m"
yellow="\e[0;33m"
norm="\e[0;0m"
}

unsetcolor ()
{
red=""; green=""
yellow=""; norm=""
}

# Return hosts. sysfs must be mounted
findhosts_26 ()
{
hosts=
if ! ls /sys/class/scsi_host/host* >/dev/null 2>&1; then
echo "No SCSI host adapters found in sysfs"
exit 1;
#hosts=" 0"
#return
fi
for hostdir in /sys/class/scsi_host/host*; do
hostno=${hostdir#/sys/class/scsi_host/host}
hostname=`cat $hostdir/proc_name`
hosts="$hosts $hostno"
echo "Host adapter $hostno ($hostname) found."
done
}

# Return hosts. /proc/scsi/HOSTADAPTER/? must exist
findhosts ()
{
hosts=
for driverdir in /proc/scsi/*; do
driver=${driverdir#/proc/scsi/}
if test $driver = scsi -o $driver = sg -o $driver = dummy -o $driver = device_info; then continue; fi
for hostdir in $driverdir/*; do
name=${hostdir#/proc/scsi/*/}
if test $name = add_map -o $name = map -o $name = mod_parm; then continue; fi
num=$name
driverinfo=$driver
if test -r $hostdir/status; then
num=$(printf '%d\n' `sed -n 's/SCSI host number://p' $hostdir/status`)
driverinfo="$driver:$name"
fi
hosts="$hosts $num"
echo "Host adapter $num ($driverinfo) found."
done
done
}

# Test if SCSI device $host $channen $id $lun exists
# Outputs description from /proc/scsi/scsi, returns new
testexist ()
{
grepstr="scsi$host Channel: 0*$channel Id: 0*$id Lun: 0*$lun"
new=`cat /proc/scsi/scsi | grep -e"$grepstr"`
if test ! -z "$new"; then
cat /proc/scsi/scsi | grep -e"$grepstr"
cat /proc/scsi/scsi | grep -A2 -e"$grepstr" | tail -n2 | pr -o4 -l1
fi
}

# Perform search (scan $host)
dosearch ()
{
for channel in $channelsearch; do
for id in $idsearch; do
for lun in $lunsearch; do
new=
devnr="$host $channel $id $lun"
echo "Scanning for device $devnr ..."
printf "${yellow}OLD: $norm"
testexist
if test ! -z "$remove" -a ! -z "$new"; then
# Device exists and we're in remove mode, so remove and readd
echo "scsi remove-single-device $devnr" >/proc/scsi/scsi
echo "scsi add-single-device $devnr" >/proc/scsi/scsi
printf "\r\x1b[A\x1b[A\x1b[A${yellow}OLD: $norm"
testexist
if test -z "$new"; then
printf "\r${red}DEL: $norm\r\n\n\n\n"; let rmvd+=1;
fi
fi
if test -z "$new"; then
# Device does not exist, try to add
printf "\r${green}NEW: $norm"
echo "scsi add-single-device $devnr" >/proc/scsi/scsi
testexist
if test -z "$new"; then
# Device not present
printf "\r\x1b[A";
# Optimization: if lun==0, stop here (only if in non-remove mode)
if test $lun = 0 -a -z "$remove" -a $optscan = 1; then
break;
fi
else
let found+=1;
fi
fi
done
done
done
}

# main
if test @$1 = @--help -o @$1 = @-h -o @$1 = @-?; then
echo "Usage: rescan-scsi-bus.sh [options] [host [host ...]]"
echo "Options:"
echo " -l activates scanning for LUNs 0-7 [default: 0]"
echo " -w scan for target device IDs 0 .. 15 [default: 0-7]"
echo " -c enables scanning of channels 0 1 [default: 0]"
echo " -r enables removing of devices [default: disabled]"
echo "--remove: same as -r"
echo "--nooptscan: don't stop looking for LUNs is 0 is not found"
echo "--color: use coloured prefixes OLD/NEW/DEL"
echo "--hosts=LIST: Scan only host(s) in LIST"
echo "--channels=LIST: Scan only channel(s) in LIST"
echo "--ids=LIST: Scan only target ID(s) in LIST"
echo "--luns=LIST: Scan only lun(s) in LIST"
echo " Host numbers may thus be specified either directly on cmd line (deprecated) or"
echo " or with the --hosts=LIST parameter (recommended)."
echo "LIST: A[-B][,C[-D]]... is a comma separated list of single values and ranges"
echo " (No spaces allowed.)"
exit 0
fi

expandlist ()
{
list=$1
result=""
first=${list%%,*}
rest=${list#*,}
while test ! -z "$first"; do
beg=${first%%-*};
if test "$beg" = "$first"; then
result="$result $beg";
else
end=${first#*-}
result="$result `seq $beg $end`"
fi
test "$rest" = "$first" && rest=""
first=${rest%%,*}
rest=${rest#*,}
done
echo $result
}

if test ! -d /proc/scsi/; then
echo "Error: SCSI subsystem not active"
exit 1
fi

# defaults
unsetcolor
lunsearch="0"
idsearch=`seq 0 7`
channelsearch="0"
remove=""
optscan=1
if test -d /sys/class/scsi_host; then
findhosts_26
else
findhosts
fi

# Scan options
opt="$1"
while test ! -z "$opt" -a -z "${opt##-*}"; do
opt=${opt#-}
case "$opt" in
l) lunsearch=`seq 0 7` ;;
w) idsearch=`seq 0 15` ;;
c) channelsearch="0 1" ;;
r) remove=1 ;;
-remove) remove=1 ;;
-hosts=*) arg=${opt#-hosts=}; hosts=`expandlist $arg` ;;
-channels=*) arg=${opt#-channels=};channelsearch=`expandlist $arg` ;;
-ids=*) arg=${opt#-ids=}; idsearch=`expandlist $arg` ;;
-luns=*) arg=${opt#-luns=}; lunsearch=`expandlist $arg` ;;
-color) setcolor ;;
-nooptscan) optscan=0 ;;
*) echo "Unknown option -$opt !" ;;
esac
shift
opt="$1"
done

# Hosts given ?
if test "@$1" != "@"; then
hosts=$*;
fi

echo "Scanning hosts $hosts channels $channelsearch for "
echo " SCSI target IDs " $idsearch ", LUNs " $lunsearch
test -z "$remove" || echo " and remove devices that have disappeared"
declare -i found=0
declare -i rmvd=0
for host in $hosts; do
dosearch;
done
echo "$found new device(s) found. "
echo "$rmvd device(s) removed. "




No se os olvide asignarle permisos de ejecucion (chmod 755 script.sh) y en el caso que os falle el texto de arriba podeis bajarlo directamente desde aqui .

miércoles, 13 de julio de 2011

Linux es diabolico!

Quienes hemos tenido la oportunidad de conocer el entorno LINUX, sabemos que este es un sórdido mundo, donde lo malo, demoníaco y bizarro se presenta en la más diabólica y cruel de sus expresiones.

Link completo: