ASM 11.2: Instantiating disk: failed at createdisk

[root@oracle-node-2 ~]$ more /etc/redhat-release

Red Hat Enterprise Linux Server release 6.3 (Santiago)

[root@oracle-node-2 dev]# oracleasm createdisk DISK1 /dev/sdb1

Writing disk header: done

Instantiating disk: failed

Clearing disk header: done

It appears that Security Linux was blocking acces to the header of disk.

[root@oracle-node-2 log]# cd /etc/selinux

[root@oracle-node-2 selinux]# more config

SELINUX=enforcing

SELINUXTYPE=targeted

Disable SELINUX

 [root@oracle-node-2 selinux]# vi config

SELINUX=disabled

After REBOOT

[root@oracle-node-2 ~]# getenforce

Disabled

[root@oracle-node-2 ~]# oracleasm createdisk DISK1 /dev/sdb1

Writing disk header: done

Instantiating disk: done

[root@oracle-node-2 ~]# cd /dev/oracleasm/disks

[root@oracle-node-2 disks]# ls

DISK1

Then scan ASM disks on other node: 

[root@oracle-node-1 dev]# oracleasm scandisks

Reloading disk partitions: done

Cleaning any stale ASM disks...

Scanning system for ASM disks...

[root@oracle-node-1 dev]#