[root@hostname]# /etc/init.d/oracleasm createdisk DATA_0001 /dev/sdb4

Marking disk "DATA_0001" as an ASM disk:                   [  OK  ]

[root@hostname]# /etc/init.d/oracleasm createdisk DATA_0002 /dev/sdb1

Marking disk "DATA_0002" as an ASM disk:                   [FAILED]

Check the reason in logs: /var/log/oracleasm

Unable to open device "/dev/sdb1": Device or resource busy

Solution:

[root@hostname]#  /usr/sbin/asmtool -C -l /dev/oracleasm -n DATA_0002 -s /dev/sdb1 -a force=yes

[root@hostname]#  /usr/sbin/asmtool -C -l /dev/oracleasm -n DATA_0003 -s /dev/sdb2 -a force=yes

[root@hostname]#  /usr/sbin/asmtool -C -l /dev/oracleasm -n REDO_0001 -s /dev/sdb3 -a force=yes

[root@hostname]#  /usr/sbin/asmtool -C -l /dev/oracleasm -n INDX_0001 -s /dev/sdb5 -a force=yes

[root@hostname]#  /usr/sbin/asmtool -C -l /dev/oracleasm -n INDX_0002 -s /dev/sdb6 -a force=yes

[root@hostname]# /etc/init.d/oracleasm listdisks

DATA_0001

DATA_0002

DATA_0003

INDX_0001

INDX_0002

REDO_0001

Fixing the Permission:

[root@hostname]#  /etc/init.d/oracleasm scandisks

Scanning the system for Oracle ASMLib disks:               [  OK  ]