#!/bin/bash

# (C) ken chase, alliance technologies 2005
# v0.02 2005sep27 - basic inception, gives status from /proc/mdstat
# v0.03 2005sep29 - check for component devices, if none, exit
# v0.04 2005sep30 - adapted for 2.6 kernels, which dont give err exit codes
#			for mdadm - now bases action on text output
# v0.05 2005oct04 - updated so works with 2.4 (err exit code) or 2.6 (text) 

mdadm=/root/mdadm-1.12.0/mdadm

if [ -z "$1" ]; then
  cat <<"EOF"
  Usage: $0 [md device]

  Will thrash /dev/[device] (an md device addressable with $mdadm) by
  removing each of component drives/partitions in turn from the array,
  and readding them, letting the array rebuild.
EOF
  exit
fi


drives=`$mdadm --detail /dev/$1 | grep '^[ ]*[0-9]' | rev | cut -d " " -f1 | rev | grep /dev/`

if [ -z "$drives" ]; then
  echo "Device /dev/$1 has no devices... EXITING..."
  exit
fi

while :; do

it=$[ $it+1 ]
echo "*** ITERATION $it `date` ***"
echo
echo "errorcode 1 = rebuilding. 2+ = more than 1 device failed. 3+ = failure"
echo
echo "Component devices:"
echo " "$drives
echo

for i in $drives; do
#  while ! $mdadm --detail /dev/$1 --test >& /dev/null; do

  echo state is `$mdadm --detail /dev/$1 | grep "State :"`
  echo

  while $mdadm --detail /dev/$1 | grep -q "State.*degraded" ||
   ! $mdadm --detail /dev/$1 --test >& /dev/null; do
    state=`$mdadm --detail /dev/$1 | grep "State :" | cut -d : -f2-`
    echo -ne "\r`date +%H:%M:%S` /dev/$1: $state \
      `grep -A2 $1 /proc/mdstat | 
       tail -1 | 
       tr -s " \t" " " | 
       sed 's/\[.*\]//' | 
       sed 's/[a-z]*[ ]*=//g' |
       sed 's/clean //' |
       sed 's/(.*)//' |
       tr -s ' '`"
#    if [ $err -ge 2 ]; then
#      echo "Error code $err!!!  HALTING!!!"
#     exit
#    fi
    sleep 2
  done
  echo
  echo "===================================================================="
  echo -n "Failing $i...."
  $mdadm --manage /dev/$1 --fail $i
  sleep 1

  echo -n "Removing $i..."
  $mdadm --manage /dev/$1 --remove $i
  sleep 1

  echo -n "Re-adding $i.."
  $mdadm --manage /dev/$1 --add $i
  sleep 1

  echo
  echo "Waiting for rebuild of $1..."
  echo

  sleep 5
done

done


#
# #root@nl6:/var/log>cat /proc/mdstat 
#Personalities : [raid5] 
#read_ahead 1024 sectors
#Event: 22                  
#md0 : active raid5 sdb1[11] sdj1[8] sdl1[10] sdk1[9] sdi1[7] sdh1[6] sdg1[5] sdf1[4] sde1[3] sdd1[2] sdc1[1]
#      48916480 blocks level 5, 64k chunk, algorithm 2 [11/10] [_UUUUUUUUUU]
#      [=========>...........]  recovery = 45.2% (2213648/4891648) finish=7.9min speed=5591K/sec
#md1 : active raid5 sdl2[10](F) sdk2[9] sdj2[8] sdi2[7] sdh2[6] sdg2[5] sdf2[4] sde2[3] sdd2[2] sdc2[1] sdb2[0]
#      9879040 blocks level 5, 64k chunk, algorithm 2 [11/10] [UUUUUUUUUU_]
#      
#unused devices: <none>
#


#/dev/md1:
#        Version : 00.90.00
#  Creation Time : Fri Sep 23 12:16:00 2005
#     Raid Level : raid5
#     Array Size : 9879040 (9.42 GiB 10.12 GB)
#    Device Size : 987904 (964.75 MiB 1011.61 MB)
#   Raid Devices : 11
#  Total Devices : 12
#Preferred Minor : 1
#    Persistence : Superblock is persistent
#
#    Update Time : Mon Sep 26 17:16:11 2005
#          State : dirty, no-errors
# Active Devices : 11
#Working Devices : 11
# Failed Devices : 1
#  Spare Devices : 0
#
#         Layout : left-symmetric
#     Chunk Size : 64K
#
#    Number   Major   Minor   RaidDevice State
#       0       8       18        0      active sync   /dev/sdb2
#       1       8       34        1      active sync   /dev/sdc2
#       2       8       50        2      active sync   /dev/sdd2
#       3       8       66        3      active sync   /dev/sde2
#       4       8       82        4      active sync   /dev/sdf2
#       5       8       98        5      active sync   /dev/sdg2
#       6       8      114        6      active sync   /dev/sdh2
#       7       8      130        7      active sync   /dev/sdi2
#       8       8      146        8      active sync   /dev/sdj2
#       9       8      162        9      active sync   /dev/sdk2
#      10       8      178       10      active sync   /dev/sdl2
#           UUID : a2e82a7f:c0920995:d9c94456:20737321
#         Events : 0.23
#::0::
#