Cloning databases

IBM® Storage Protect Snapshot uses the FlashCopy® or snapshot function of the storage solutions for database cloning. This method eliminates downtime and minimizes the impact on the production database.

For FlashCopy backup, the physical volume identification numbers (PVIDs) are not changed. For FlashCopy cloning, the PVIDs of the FlashCopy target disks are automatically changed by the IBM Storage Protect Snapshot software. You can have several cloned databases of one source database that are running on one host. Each clone target requires a unique database name.

With IBM Storage Protect Snapshot, a cloning process can be started with an online or offline source database. For online IBM Storage Protect Snapshot cloning, the source database is suspended for a short time. The suspension occurs when the storage system creates its FlashCopy or snapshot of the source database.

The cloned database (target database) can have the same database name as the source database. The cloned database can also be renamed to any valid database name during the IBM Storage Protect Snapshot cloning process. Each clone target requires a unique database name.IBM Storage Protect Snapshot requires the cloned database to be created on a different database server than the source database server regardless of whether the clone database name is changed.

Archiving logs on cloned databases

Note: Do not run any queries or operations on the Oracle database and ASM instance on the clone system while IBM Storage Protect Snapshot clone operations are running.

When the source database cloned is in ARCHIVELOG mode, the resulting cloned database will not be configured as ARCHIVELOG but as NOARCHIVELOG mode. If you want to archive redo logs on the cloned database you must configure the database to enable archive logging, and specify a valid path to store the logs.

Cloning and IBM System Storage® SAN Volume Controller

When you clone databases and use IBM System Storage SAN Volume Controller, the space-efficient disks can be used as a target for FlashCopy cloning operations. However, when you use SAN Volume Controller space-efficient disks as a target for FlashCopy cloning, there are restrictions on the FlashCopy backups. You can complete cloning operations from the cloning source volumes. If you want to complete FlashCopy backup and FlashCopy cloning from the same source disks, use full target disks.

To use SAN Volume Controller space-efficient disks, in the DEVICE_CLASS that is used for cloning operations, set the ALLOW_NOCOPY_FLASHCOPY parameter to YES.