Description of problem:

I cannot mdadm --manage --stop /dev/md10 or raidstop /dev/md10 on 
an unused but active linux software array.

Here is /proc/mdstat:
# cat /proc/mdstat
Personalities : [raid1] [raid5]
read_ahead 1024 sectors
Event: 5
md10 : active raid5 sde1[0] sdl1[7] sdk1[6] sdj1[5] sdi1[4] sdh1[3]
sdg1[2] sdf1[1]
      124430656 blocks level 5, 64k chunk, algorithm 0 [8/8] [UUUUUUUU]
       
md0 : active raid1 sdb1[1] sda1[0]
      136448 blocks [2/2] [UU]
       
md2 : active raid1 sdb2[1] sda2[0]
      2096384 blocks [2/2] [UU]
       
md1 : active raid1 sdb3[1] sda3[0]
      6650816 blocks [2/2] [UU]
       
md3 : active raid1 sdd1[1] sdc1[0]
      8883840 blocks [2/2] [UU]
       
unused devices: <none>

Here is the output of mdadm --examine --scan
# mdadm --examine --scan
ARRAY /dev/md0 level=raid1 num-devices=2
UUID=1adde9c7:e77194da:43bc5f52:76e7a23d
   devices=/dev/sdb1,/dev/sda1
ARRAY /dev/md3 level=raid1 num-devices=2
UUID=a544ff0c:ad65467c:3ad51db9:576bd4b4
   devices=/dev/sdd1,/dev/sdc1
ARRAY /dev/md10 level=raid5 num-devices=8
UUID=b24e52ec:7951c2c5:67b0240a:efb64382
  
devices=/dev/sdl1,/dev/sdk1,/dev/sdj1,/dev/sdi1,/dev/sdh1,/dev/sdg1,/dev/sdf1,/dev/sde1


Version-Release number of selected component (if applicable):

Kernel version 2.4.21-15.0.4.ELsmp

How reproducible:

All the time.

Steps to Reproduce:

Make any arbitrary raid array unused and attempt to stop the array.

For example:

Steps to Reproduce:
1. umount /boot
2. mdadm --manage --stop /dev/md0
  
Actual results:

raid array continues running because it is seen as in use.

Expected results:

raid array should stop.

Additional info: