With the latest software release for the Oracle Database Appliance (ODA), Oracle has decided to make ACFS (ASM Cluster FileSystem) the default storage for all new databases. This is a major change for Oracle since ACFS previously had not allowed Oracle data files to be stored on it. ACFS was introduced in Oracle 11.2 and has been proven to be stable and feature rich. However, not until recently has Oracle compared the performance of ACFS to Native ASM.
ACFS is a full-featured cluster filesystem that was introduced with Oracle database release 11gR2 but has been enhanced with each release since then. It now supports all Oracle data file types and is the recommended choice for storage starting with ODA software release 12.x. ASM and ACFS have been optimized for the highest level of performance with Oracle databases as well as general storage requirements such as Virtual Machine (VM) files.
With the 12.x release of the ODA software all databases created with oakcli will create an ACFS filesystem and repository (if it doesn’t already exist) for database storage. With the latest 12.x release of Exadata with OVM (Oracle VM) this will also be the default storage option. Unfortunately if you decide to use ACFS for Exadata database storage you will currently be unable to take advantage of the Oracle Smart Scan option.
In addition to being a general purpose clustered filesystem ACFS offers the following features:
- Point-in-Time Read-Write Snapshots
- High Availability NFS