Storage Foundation for Oracle® RAC 7.4.1 Administrator's Guide - Linux
- Section I. SF Oracle RAC concepts and administration
- Overview of Storage Foundation for Oracle RAC
- About Storage Foundation for Oracle RAC
- Component products and processes of SF Oracle RAC
- About Virtual Business Services
- Administering SF Oracle RAC and its components
- Administering SF Oracle RAC
- Starting or stopping SF Oracle RAC on each node
- Administering VCS
- Administering I/O fencing
- About the vxfentsthdw utility
- Testing the coordinator disk group using the -c option of vxfentsthdw
- About the vxfenadm utility
- About the vxfenclearpre utility
- About the vxfenswap utility
- Administering the CP server
- Administering CFS
- Administering CVM
- Changing the CVM master manually
- Administering Flexible Storage Sharing
- Backing up and restoring disk group configuration data
- Administering SF Oracle RAC global clusters
- Administering SF Oracle RAC
- Overview of Storage Foundation for Oracle RAC
- Section II. Performance and troubleshooting
- Troubleshooting SF Oracle RAC
- About troubleshooting SF Oracle RAC
- Troubleshooting I/O fencing
- Fencing startup reports preexisting split-brain
- Troubleshooting CP server
- Troubleshooting server-based fencing on the SF Oracle RAC cluster nodes
- Issues during online migration of coordination points
- Troubleshooting Cluster Volume Manager in SF Oracle RAC clusters
- Troubleshooting CFS
- Troubleshooting interconnects
- Troubleshooting Oracle
- Troubleshooting ODM in SF Oracle RAC clusters
- Prevention and recovery strategies
- Tunable parameters
- Troubleshooting SF Oracle RAC
- Section III. Reference
CVM recovery
When a node leaves a cluster, the new membership is delivered by GAB, to CVM on existing cluster nodes. The fencing driver (VXFEN) ensures that split-brain scenarios are taken care of before CVM is notified. CVM then initiates recovery of mirrors of shared volumes that might have been in an inconsistent state following the exit of the node.
For database files, when ODM is enabled with SmartSync option, Oracle Resilvering handles recovery of mirrored volumes. For non-database files, this recovery is optimized using Dirty Region Logging (DRL). The DRL is a map stored in a special purpose VxVM sub-disk and attached as an additional plex to the mirrored volume. When a DRL subdisk is created for a shared volume, the length of the sub-disk is automatically evaluated so as to cater to the number of cluster nodes. If the shared volume has Fast Mirror Resync (FlashSnap) enabled, the DCO (Data Change Object) log volume created automatically has DRL embedded in it. In the absence of DRL or DCO, CVM does a full mirror resynchronization.