Format the ASM disk and reuse the Free disk as candidate disk.
Format the ASM Disk or Remove candidate disk during installation in oracle.
Check the device which you want to format and remove from the ASM utilization or reuse purpose in asm.
During installation we select the disk for installation, but due to some failure in installation, when we tried to installed oracle again, it will not show the disk in available. So, to get the list again we need to run the following command dd provided by linux/unix/mac OS.
In Linux, you can get the list as follows:
# /etc/init.d/oracleasm listdisks
Check the entries of the disk map in rawdevices files
#more /etc/sysconfig/rawdevices
if you asm is already configured then you can check from lsdsk command lists information
#select query from the V$ASM_DISK_STAT and V$ASM_DISK views.
# asmcd
asmcd> lsdsk
Suppose /dev/sdd/dev01 is used by asm. you want to format and reuse it again.
Place that disk name in OF parameter of following command and Format it.
#dd if=/dev/zero of=/dev/sdd/dev01 bs=8192 count=4
dd can modify data in place. For example, this overwrites the first 8192 bytes of a file with null bytes.
if : means read from the file
of: means write to the file
bs: read and write bytes at a time.
count: copy only that no of blocks