12C ASM: THE NEW ASM FRONTIER
When Automatic Storage Management (ASM) was introduced in 10gR1 and ASM was designed as a purpose-built host based volume management and file system that is integrated with the Oracle database. It is built on stripping and mirroring methodology (SAME) and providing the ability of rebalancing the file layout online, whenever the physical storage configuration changes. ASM is built on the Oracle instance architecture. From the users view, ASM exposes Disk Groups. These Disk Groups consists of ASM disks and files that are stripped across all the disks in a Disk Group. The Disk Groups are global in nature and the database instances running individually or in clusters have shared access to the Disk Groups and the files within them. ASM instances that access the same set of storage and under the realm of single CSS domain, to form an ASM cluster. With the advent of 11gR2, ASM become not only a significant part of the Oracle Clusterware stack, but is also a core component of engineered systems such as Exadata and ODA. Oracle 12c was announced in 2013, and along with this 12c release, came significant changes for ASM.