An ASM volume device is the OS dependent device file that is normally used to access disk-type devices. The naming of the ASM volume device will include the ASM diskgroup name and the ASM volume file name specified by the administrator at volume file creation time. For example, an ASM volume named vol1 in diskgroupa and another ASM volume named vol1 in diskgroupb would have their device name in Unix variants as: /dev/asm/diskgroupa/vol1 /dev/asm/diskgroupb/vol1 The ASM volume device file will be created automatically when an ASM volume is created. Also once a diskgroup is mounted in an ASM instance and contains ASM volume files, volumes can be enabled which will cause the corresponding volume device files to be created. The disk group mount and volume enable can happen automatically upon ASM instance startup. The volume device file names are cluster wide unique and persistent across all nodes in the cluster which have an ASM instance running with the diskgroup mounted and volumes enabled. When a node boots into the cluster and the ASM instance is started, the cluster wide unique volume device files are created once the diskgroup is mounted which contains volume files and the volumes are enabled.