tests/21raid5cache

   1 # check data integrity with raid5 write back cache
   2
   3 # create a 4kB random file and 4 files each with a 1kB chunk of the random file:
   4 #    randfile: ABCD   randchunk[0-3]:  A  B  C  D
   5 #
   6 # then create another random 1kB chunk E, and a new random page with A, B, E, D:
   7 #    randchunk4: E    newrandfile:   ABED
   8 create_random_data() {
   9     dd if=/dev/urandom of=/tmp/randfile bs=4k count=1
  10     for x in {0..3}
  11     do
  12         dd if=/tmp/randfile of=/tmp/randchunk$x bs=1k count=1 skip=$x count=1
  13     done
  14
  15     dd if=/dev/urandom of=/tmp/randchunk4 bs=1k count=1
  16
  17     rm /tmp/newrandfile
  18     for x in 0 1 4 3
  19     do
  20         cat /tmp/randchunk$x >> /tmp/newrandfile
  21     done
  22 }
  23
  24 # create array, $1 could be 5 for raid5 and 6 for raid6
  25 create_array() {
  26     if [ $1 -lt 5 -o $1 -gt 6 ]
  27     then
  28         echo wrong array type $1
  29         exit 2
  30     fi
  31
  32     mdadm -CR $md0 -c4 -l5 -n10 $dev0 $dev1 $dev2 $dev3 $dev4 $dev5 $dev6 $dev11 $dev8 $dev9 --write-journal $dev10
  33     check wait
  34     echo write-back > /sys/block/md0/md/journal_mode
  35 }
  36
  37 restart_array_write_back() {
  38     mdadm -S $md0
  39     mdadm -A $md0 $dev0 $dev1 $dev2 $dev3 $dev4 $dev5 $dev6 $dev11 $dev8 $dev9 $dev10
  40     echo write-back > /sys/block/md0/md/journal_mode
  41 }
  42
  43 # compare the first page of md0 with file in $1
  44 cmp_first_page() {
  45     cmp  -n 4096 $1 $md0 || { echo cmp failed ; exit 2 ; }
  46 }
  47
  48 # write 3 pages after the first page of md0
  49 write_three_pages() {
  50     for x in {1..3}
  51     do
  52         dd if=/dev/urandom of=$md0 bs=4k count=1 seek=$x count=1
  53     done
  54 }
  55
  56 # run_test <array_type:5/6> <degraded_or_not:yes/no>
  57 run_test() {
  58     create_random_data
  59     create_array $1
  60
  61     if [ $2 == yes ]
  62     then
  63         mdadm --fail $md0 $dev0
  64     fi
  65
  66     dd if=/tmp/randfile of=$md0 bs=4k count=1
  67     restart_array_write_back
  68     cmp_first_page /tmp/randfile
  69     restart_array_write_back
  70     write_three_pages
  71     cmp_first_page /tmp/randfile
  72
  73
  74     dd if=/tmp/randchunk4 of=/dev/md0 bs=1k count=1 seek=2
  75     restart_array_write_back
  76     cmp_first_page /tmp/newrandfile
  77     restart_array_write_back
  78     write_three_pages
  79     cmp_first_page /tmp/newrandfile
  80
  81     mdadm -S $md0
  82 }
  83
  84 run_test 5 no
  85 run_test 5 yes
  86 run_test 6 no
  87 run_test 6 yes