8.5.1 Overview of Oracle Exadata Database Server Updates
When updating database servers, there is more than one software that needs to be updated.
Oracle Exadata database server release updates contain updates for the following components within a database server:
- Oracle Linux operating system
- Firmware (Disk, RAID controller, ILOM, HCA)
- Oracle Exadata System Software
The software and firmware components that are updated for a specific release depend on the current Oracle Exadata System Software release the database server is running and the release you are updating to. Oracle Linux operating system packages and Oracle Exadata System Software are always updated while firmware may be updated for only a small selection of the components or not at all.
Updates for Oracle Exadata database servers can be applied independently from the storage servers or RDMA Network Fabric switches unless otherwise specified in My Oracle Support Note 888828.1.
Updating database servers is always performed in-place. This means the active operating system is updated. The actual update is performed using YUM, but the command to do this is wrapped in an Oracle Exadata utility called patchmgr.
The YUM command is wrapped in the update utility to maintain strict ordering of validation and preparation steps during the update process. Also by using a utility Oracle can enforce application of fixes for known issues and best practices.
Oracle Clusterware processes and Oracle Real Application Clusters (Oracle RAC) database instances must not be running on a database server that is being updated. To reduce application-level impact, follow the client failover best practices described in the "Client Failover Best Practices for Highly Available Oracle Databases" technical reference paper.
If you cannot afford cluster-wide downtime, you can update database servers in a rolling fashion. This means updating one database server at a time. If you can afford cluster-wide downtime, you can update all database servers in parallel. Non-rolling updates reduce the overall time required to complete the upgrade at the expense of having a full database outage.