Oracleasm deletedisk failed Unable to clear disk

Hi Guys,


Today , I dropped a asm diskgroup. After that when I am planning to delete asm disks of diskgroup its showing error like
"

#oracleasm deletedisk -v DISK1

Clearing disk header: oracleasm-write-label: Unable to open device "/dev/oracleasm/disks/DISK1": Device or resource busy
failed
Unable to clear disk "DISK1"

or

 oracleasm deletedisk -v DISK6

Clearing disk header: oracleasm-write-label: Unable to open device "/dev/mapper/multipathbp1": Device or resource busy
failed
Unable to clear disk "DISK1"

Cause:  This disk header already in use.

Solution: we have to clear header forcely

step1:

root@rac1 ~]# blkid |grep oracleasm

/dev/sdd1: LABEL="DISK1" TYPE="oracleasm"

dd if=/dev/zero of=/dev/sdd1 bs=1024 count=100

or

dd if=/dev/zero of=/dev/mapper/multipathbp1 bs=1024 count=100

step2: login as root user

#partprobe /dev/mapper/multipathbp1

step3 :

#oracleasm deletedisk -v DISK1