Oracle Replication Technologies for Non-Database Files

Oracle Advanced Cluster File System (Oracle ACFS), Oracle AI Database File System, and Oracle Solaris ZFS Storage Appliance Replication are the Oracle replication technologies for non-database files.

Table 2 Oracle Replication Technologies for Non-Database Files

Technology	Recommended Usage	Comments
Oracle Advanced Cluster File System	Recommended to provide a single-node and cluster-wide file system solution integrated with Oracle ASM, Oracle Clusterware, and Oracle Enterprise Manager technologies. Provides a loosely coupled full stack replication solution when combined with Data Guard or Oracle GoldenGate.	Oracle ACFS establishes and maintains communication with the Oracle ASM instance to participate in Oracle ASM state transitions including Oracle ASM instance and disk group status updates and disk group rebalancing. Supports many database and application files, including executables, database trace files, database alert logs, application reports, BFILEs, and configuration files. Other supported files are video, audio, text, images, engineering drawings, and other general-purpose application file data. Can provide near-time consistency between database changes and file system changes when point-in-time recovery happens Can be exported and accessed by remote clients using standard NAS File Access Protocols such as NFS and CIFS.
Oracle AI Database File System	Recommended for providing stronger synchronization between database and non-database systems.	Can be integrated with the database to maintain complete consistency between the database changes and the file system changes All data stored in the database and can be used with Oracle Active Data Guard to provide both disaster recovery and read-only access Can take advantage all of the Oracle database features
Oracle Solaris ZFS Storage Appliance Replication	Recommended for disaster recovery protection for non-database files, and specifically for Oracle Fusion Middleware critical files stored outside of the database.	Replicates all non-database objects, including Oracle Fusion Middleware binaries configuration Can provide near time consistency between database changes and file system changes when point-in-time recovery happens

Technology

Recommended Usage

Comments

Oracle Advanced Cluster File System

Recommended to provide a single-node and cluster-wide file system solution integrated with Oracle ASM, Oracle Clusterware, and Oracle Enterprise Manager technologies. Provides a loosely coupled full stack replication solution when combined with Data Guard or Oracle GoldenGate.

Oracle ACFS establishes and maintains communication with the Oracle ASM instance to participate in Oracle ASM state transitions including Oracle ASM instance and disk group status updates and disk group rebalancing.

Supports many database and application files, including executables, database trace files, database alert logs, application reports, BFILEs, and configuration files. Other supported files are video, audio, text, images, engineering drawings, and other general-purpose application file data.

Can provide near-time consistency between database changes and file system changes when point-in-time recovery happens

Can be exported and accessed by remote clients using standard NAS File Access Protocols such as NFS and CIFS.

Oracle AI Database File System

Recommended for providing stronger synchronization between database and non-database systems.

Can be integrated with the database to maintain complete consistency between the database changes and the file system changes

All data stored in the database and can be used with Oracle Active Data Guard to provide both disaster recovery and read-only access

Can take advantage all of the Oracle database features

Oracle Solaris ZFS Storage Appliance Replication

Recommended for disaster recovery protection for non-database files, and specifically for Oracle Fusion Middleware critical files stored outside of the database.

Replicates all non-database objects, including Oracle Fusion Middleware binaries configuration

Can provide near time consistency between database changes and file system changes when point-in-time recovery happens

Oracle Advanced Cluster File System

Oracle Advanced Cluster File System (ACFS) is a multiplatform, scalable file system, and storage management technology that extends Oracle Automatic Storage Management (Oracle ASM) functionality to support customer files maintained outside of Oracle AI Database.

Oracle ACFS supports many database and application files, including executables, database trace files, database alert logs, application reports, BFILEs, and configuration files. Other supported files are video, audio, text, images, engineering drawings, and other general-purpose application file data.

Oracle ACFS takes advantage of the following Oracle ASM functionality:

Oracle ACFS dynamic file system resizing
Maximized performance through direct access to Oracle ASM disk group storage
Balanced distribution of Oracle ACFS across Oracle ASM disk group storage for increased I/O parallelism
Data reliability through Oracle ASM mirroring protection mechanisms

Oracle ACFS Replication, similar to Data Guard for the database, enables replication of Oracle ACFS file systems across the network to a remote site, providing disaster recovery capability for the file system. Oracle ACFS replication captures file system changes written to disk for a primary file system and records the changes in files called replication logs. These logs are transported to the site hosting the associated standby file system where background processes read the logs and apply the changes recorded in the logs to the standby file system. After the changes recorded in a replication log are successfully applied to the standby file system, the replication log is deleted from the sites hosting the primary and standby file systems.

An additional feature of Oracle ACFS is that it offers snapshot-based replication for generic and application files, providing an HA solution for disaster recovery and Test/Development environments. Oracle AI Databases stored in ACFS can leverage Oracle Multiltenant and ACFS snapshot technologies to create quick and efficient snapshot clones of pluggable databases.

Oracle Data Guard and Oracle ACFS can be combined to provide a full stack high availability solution with Data Guard protecting the database with a standby database and Oracle ACFS replicating the file system changes to the standby host. For planned outages the file system and the database remain consistent to a point in time with zero data loss.

See Also: Oracle ACFS ASM Cluster File System: What is it and How to use it http://www.oracle.com/goto/maa for Oracle MAA technical brief “Full Stack Role Transition - Oracle ACFS and Oracle Data Guard”

Oracle AI Database File System

Oracle AI Database File System (DBFS) takes advantage of the features of the database to store files, and the strengths of the database in efficiently managing relational data, to implement a standard file system interface for files stored in the database.

With this interface, storing files in the database is no longer limited to programs specifically written to use BLOB and CLOB programmatic interfaces. Files in the database can now be transparently accessed using any operating system (OS) program that acts on files. For example, extract, transform, and load (ETL) tools can transparently store staging files in the database.

Oracle DBFS provides the following benefits:

Full stack integration recovery and failover: By storing file system files in a database structure, it is possible to easily perform point-in-time recovery of both database objects and file system data.
Disaster Recovery System Return on Investment (ROI): All changes to files contained in DBFS are also logged through the Oracle database redo log stream and thus can be passed to a Data Guard physical standby database. Using Oracle Active Data Guard technology, the DBFS file system can be mounted read-only using the physical standby database as the source. Changes made on the primary are propagated to the standby database and are visible once applied to the standby.
File system backups: Because DBFS is stored in the database as database objects, standard RMAN backup and recovery functionality can be applied to file system data. Any backup, restore, or recovery operation that can be performed on a database or object within a database can also be performed against the DBFS file system. See Also: Database File System (DBFS)

Oracle Solaris ZFS Storage Appliance Replication

The Oracle Solaris ZFS Storage Appliance series supports snapshot-based replication of projects and shares from a source appliance to any number of target appliances manually, on a schedule, or continuously.

The Oracle Solaris ZFS Storage Appliance series supports the following use cases:

Disaster recovery: Replication can be used to mirror an appliance for disaster recovery. In the event of a disaster that impacts the service of the primary appliance (or even an entire data center), administrators activate the service at the disaster recovery site, which takes over using the most recently replicated data. When the primary site is restored, data changed while the disaster recovery site was in service can be migrated back to the primary site, and normal service is restored. Such scenarios are fully testable before a disaster occurs.
Data distribution: Replication can be used to distribute data (such as virtual machine images or media) to remote systems across the world in situations where clients of the target appliance would not ordinarily be able to reach the source appliance directly, or such a setup would have prohibitively high latency. One example uses this scheme for local caching to improve latency of read-only data (such as documents).
Disk-to-disk backup: Replication can be used as a backup solution for environments in which tape backups are not feasible. Tape backup might not be feasible, for example, because the available bandwidth is insufficient or because the latency for recovery is too high.
Data migration: Replication can be used to migrate data and configuration between Oracle Solaris ZFS Storage appliances when upgrading hardware or rebalancing storage. Shadow migration can also be used for this purpose.

The architecture of Oracle Solaris ZFS Storage Appliance also makes it an ideal platform to complement Data Guard for disaster recovery of Oracle Fusion Middleware. Oracle Fusion Middleware has a number of critical files that are stored outside of the database. These binaries, configuration data, metadata, logs and so on also require data protection to ensure availability of the Oracle Fusion Middleware. For these, the built-in replication feature of the ZFS Storage Appliance is used to move this data to a remote disaster recovery site.

Benefits of the Oracle Solaris ZFS Storage Appliance when used with Oracle Fusion Middleware include:

Leverages remote replication for Oracle Fusion Middleware
Provides ability to quickly create clones and snapshots of databases to increase ROI of DR sites See Also: Oracle ZFS Storage Appliance Software