Serviceguard Extended Distance Cluster (EDC) with VxVM/CVM Mirroring on HP-UX, May 2008

Oracle Cluster Registry and Vote Disk

Oracle 10g Release 2 supports up to two copies of the Oracle Cluster Registry (OCR) and up to three

vote disks. For EDC, each copy of OCR and each vote disk are required to be physically mirrored by

software (CVM mirroring) between the two datacenters.

In the event of a loss of communication between the datacenters, the quorum server serves as a tie-

breaker for Serviceguard. The CVM mirrored OCR and vote disks ensure that Oracle Clusterware has

access to local physical copies for Oracle Clusterware cluster reformation.

Oracle Clusterware and Oracle Database Binaries

For EDC configurations, it is recommended to maintain local storage for Oracle Clusterware and

Oracle Database binaries and HOME, to reduce inter-site traffic.

Oracle Database Datafiles

Database datafiles are required to be physically mirrored by CVM to both datacenters, when using

CFS and CVM.

Database Recovery Data

For EDC, when using SLVM or CVM, the database recovery data should reside locally and must be

made available to the RAC instance performing the recovery. The benefit of using CFS for database

recovery data is the ease by which recovery data is made available to all instances - the database

recovery data is physically mirrored to both datacenters. Recovery data can include archive redo logs

and the flash recovery area, if configured.