How to clear asm disk headers

Use the below command if you want to clear an ASM disk header. We may want to do that if we want to reuse the disk to add it to some other diskgroup.

$ dd if=/dev/zero of=/dev/raw/raw1 bs=8192 count=12800
12800+0 records in
12800+0 records out
104857600 bytes (105 MB) copied, 3.78717 seconds, 27.7 MB/s

Let us now verify the disk header..


$ kfed read /dev/raw/raw1
kfbh.endian: 0 ; 0x000: 0x00
kfbh.hard: 0 ; 0x001: 0x00
kfbh.type: 0 ; 0x002: KFBTYP_INVALID
kfbh.datfmt: 0 ; 0x003: 0x00
kfbh.block.blk: 0 ; 0x004: T=0 NUMB=0x0
kfbh.block.obj: 0 ; 0x008: TYPE=0x0 NUMB=0x0
kfbh.check: 0 ; 0x00c: 0x00000000
kfbh.fcn.base: 0 ; 0x010: 0x00000000
kfbh.fcn.wrap: 0 ; 0x014: 0x00000000
kfbh.spare1: 0 ; 0x018: 0x00000000
kfbh.spare2: 0 ; 0x01c: 0x00000000
$

KFBTYP_INVALID, indicates the disk headers are cleared. This disk should now appear as a CANDIDATE disk in the v$asm_disk.