Mir Sayeed Hassan – Oracle Blog

Error while deleting the oracleasm disks from Oracle Server

Check the disk need to delete

[root@pri-db ~]# cd /dev/oracleasm/disks/

[root@pri-db disks]# ls
ORADATA

Delete the oracleasm disk “ORADATA”

[root@pri-db disks]# oracleasm deletedisk ORADATA
Clearing disk header: failed
Unable to clear disk "ORADATA"

As we would see the disk does not deleted due to the header of the disk in unclear

Check the disk Name

[root@pri-db ~]# cd /dev/mapper/

[root@pri-db mapper]# ls
backup-backup control ol-root ol-swap Unity71-Shop-DB Unity71-Shop-DB1

[root@pri-db mapper]# ll

total 0
lrwxrwxrwx. 1 root root 7 Aug 16 20:00 backup-backup -> ../dm-2
crw-------. 1 root root 10, 236 Aug 16 20:00 control
lrwxrwxrwx. 1 root root 7 Aug 16 20:00 ol-root -> ../dm-0
lrwxrwxrwx. 1 root root 7 Aug 16 20:00 ol-swap -> ../dm-1
lrwxrwxrwx. 1 root root 7 Aug 16 20:00 Unity71-Shop-DB -> ../dm-3
lrwxrwxrwx. 1 root root 7 Aug 16 20:00 Unity71-Shop-DB1 -> ../dm-4

Clear the header of the disk by uisng the below command

[root@pri-db mapper]# dd if=/dev/mapper/Unity71-Shop-DB1 of=/tmp/Unity71-Shop-DB1_header_bck bs=4096 count=1
1+0 records in
1+0 records out
4096 bytes (4.1 kB, 4.0 KiB) copied, 0.00112731 s, 3.6 MB/s

[root@pri-db mapper]# dd if=/dev/zero of=/dev/mapper/Unity71-Shop-DB1 bs=4096 count=1
1+0 records in
1+0 records out
4096 bytes (4.1 kB, 4.0 KiB) copied, 0.00063471 s, 6.5 MB/s

Deleted the disk successfully

[root@pri-db mapper]# oracleasm deletedisk ORADATA
Disk "ORADATA" defines an unmarked device
Dropping disk: done

=====Hence deleted the disk, tested & verified in our env=====