Starting with Oracle Database 19c, Oracle Advanced Cluster File System (ACFS) and Oracle RMAN combine best-in-class backup, reliability, and scalability in a newly supported configuration.
Oracle RMAN is Oracle’s integrated backup and recovery solution for Oracle Database, supporting multiple targets. A target contains the location of a backup set which can be used to restore a database. Oracle RMAN can use multiple locations to store these backup sets. Still, the backup locations must be highly available, performant, and provide large amounts of storage to fit the needs of the database.
Oracle ACFS provides an ideal backup location, as it allows for highly available, highly scalable, and highly performant storage without requiring additional database licenses. As a bonus, Oracle ACFS is already pre-configured and available in many of Oracle’s engineered systems.
Oracle RMAN backup sets can utilize an integrated NFS client to provide high-performance flexible NFS solutions to access the backup locations. This reliable solution allows for consolidated storage management, ease of access, performance, and other advanced functionality.
In short, Oracle RMAN backup sets must be written to a highly available location to stay online for mission-critical operations. Oracle RMAN backup sets must be written to storage that is performant enough to handle the load of the Oracle Database, or performance may be compromised. Lastly, Oracle RMAN backup sets must be written to a location with enough storage or Oracle RMAN backups will fail. Traditional Linux NFS filers and essential volume managers, file systems, and other storage solutions, such as one might find in a standard Oracle Linux install, do not usually provide the higher storage consolidation and configuration level these filers provide.
Oracle ACFS is a best-in-class file system that bundles these storage consolidation features at no additional cost. A quick list of the advanced storage features of Oracle ACFS includes Online Resize for storage efficiency, high availability for maximum uptime, replication for redundancy, and varying data redundancy and availability options.
These features combined provide a compelling solution for Oracle RMAN backup sets – especially when Oracle ACFS is generally available in most configurations in which Oracle RMAN is used, often with no additional infrastructure.
As a result of intensive testing, Oracle ACFS 19c has been certified as a dNFS target for RMAN backup sets availability. Oracle ACFS was put through a series of intensive tests to achieve this certification to ensure compatibility, interoperation, performance, and high availability. At a high level, configuration is easy –configure an NFS mount point using Oracle NAS|MAX HA-NFS and add that as a dNFS target for Oracle RMAN Backups.
One of the heavily-tested features as part of the certification was storage availability. Oracle ACFS NAS|MAX HA-NFS multipathing was used during the certification effort. This configuration enables multiple network paths to a single ACFS NFS target, while typically only one path per node in the target cluster can be used. When all cluster nodes are available, this provides storage performance benefits. However, the real benefit of a multi-network path access to a target cluster is reliability in case one or more cluster nodes are not available. At this point, the Oracle NAS|MAX HA-NFS targets will move around the cluster to ensure that the NFS target continues to exist and accept data. This reliability provides higher uptime than traditional NFS storage solutions, as the NFS targets are as highly available as other RAC services.
Storage scalability was also intensively tested during the certification process using Oracle ACFS auto-resize to ensure that storage was efficiently used. For the test, the storage to the Oracle ACFS file system was not pre-allocated in large chunks but was instead kept at 20% free space. This keeps the amount of wasted storage to a minimum. As Oracle RMAN backup data sets were created, Oracle ACFS allocated additional storage to meet the increased demand. Storage can be quickly shrunk to maintain an appropriate level of used storage so that extra storage is not wasted.
Last but not least, the performance of the Oracle RMAN dNFS backup sets was evaluated. Oracle ACFS NAS|MAX HA-NFS exports were set up with standard best practices, Oracle recommended NFS options, and no additional tuning was necessary. As the test cases ran, cluster nodes were removed and added forcefully, disks were dropped and added forcefully, and network links were removed and added forcefully. Although performance might degrade during these catastrophic failure case scenarios, no performance impact was detected. Overall the result is that Oracle ACFS and the Oracle ACFS NAS|MAX extensions can easily keep up with Oracle RMAN backup’s performance, availability, and scalability requirements.
Given the many advanced features of Oracle ACFS, including the high availability benefits, the ability to scale both network and storage performance, and the fact that Oracle ACFS is available in most cluster configurations, Oracle ACFS + Oracle RMAN provides a best-in-class, easily configurable, highly available, highly performant, and highly efficient solution for Oracle Database backups.
Please, refer to https://docs.oracle.com/en/database/oracle/oracle-database/21/acfsg/understand-acfs-concepts.html#GUID-30F87EDC-188C-4F19-9035-9C0E6C4CCBE1 for more information and restrictions when using Oracle ACFS and Database Homes. The complete Oracle ACFS NAS | MAX Extensions Technical Brief can be found here: https://www.oracle.com/a/tech/docs/oracle-acfs-nas-max-extensions.pdf