The following list provides a summary of Oracle ACFS resource-based management.
The Oracle ACFS, Oracle Kernel Services (OKS), and Oracle ADVM drivers are dynamically loaded when the Oracle ASM instance is started.
Oracle ACFS
This driver processes all Oracle ACFS file and directory operations.
Oracle ADVM
This driver provides block device services for Oracle ADVM volume files that are used by file systems for creating file systems.
Oracle Kernel Services Driver (OKS)
This driver provides portable driver services for memory allocation, synchronization primitives, and distributed locking services to Oracle ACFS and Oracle ADVM.
The drivers are managed as a single resource set. For additional information, see "Oracle ACFS Drivers Resource Management" and "Oracle ACFS Driver Commands".
When a volume is created, Oracle ADVM creates a resource with the name of ora.DISKGROUP.VOLUME.advm. This resource is usually managed through transparent high availability calls from Oracle ASM and requires no user interaction. However, the user may choose to use the SRVCTL command interface to start and stop volumes as well as control the default state of the volume after an Oracle ASM restart. This is especially beneficial in a large cluster or an Oracle Flex ASM cluster, as volumes on other nodes may be operated upon.
In addition, these Oracle ADVM resources can be used by other resources in the Oracle Clusterware stack to maintain dependency chains. Dependency chains ensure that the resources a program requires to run are available. For instance, if a resource was monitoring a backup application that was backing up to Oracle ADVM volume, the backup application would want to ensure that it specified the Oracle ADVM volume resource in it's START and STOP dependency list. Because the Oracle ADVM volume resource will enable the volume, this ensures that the volume is available before the backup begins.
Oracle ACFS file systems are either manually mounted or dismounted using an Oracle ACFS or Oracle Clusterware command-line tool, or automatically mounted or dismounted based on an Oracle Clusterware resource action.
For example, a file system hosting an Oracle Database home is named in the dependency list of the associated Oracle Database resource such that issuing a start on the database resource results in mounting the dependent Oracle ACFS hosted database home file system.
Oracle ACFS file system resources provide the following actions:
MOUNT
During the START operation the resource mounts the file system on the path configured in the resource. The Oracle ACFS file system resource requires all components of the Oracle ASM stack to be active (volume device, ASM) and ensures that they are active before attempting the mount.
UNMOUNT
During the STOP operation, the resource attempts to unmount a file system.
Oracle provides two resource types for Oracle Highly Available NFS. For more information, refer to "High Availability Network File Storage for Oracle Grid Infrastructure".
As with all Oracle Clusterware resources, these resources provide for high availability by monitoring the underlying device, file system, or driver to ensure that the object remains available. In the event that the underlying object becomes unavailable, each resource attempts to make the underlying object available again.