Creating and Managing Snapshots of a Database Deployment

Oracle Database Exadata Cloud Service supports the creation of snapshot master databases, which can be used as the basis for creating space-efficient clone databases that can be created and destroyed very quickly and easily. Snapshot clones are often used for development, testing, or other purposes that require a transient database.

Note:

To create and manage snapshot masters and clones, your Exadata Cloud Service instance must be configured with the SPARSE disk group. See Creating an Exadata Cloud Service Instance.
Exadata Cloud Service supports snapshots only with Oracle Database 12c, or later. You cannot create a snapshot master of a database using Oracle Database 11g Release 2.

The snapshot master is a completely independent database deployment that contains a read-only copy of the source database. It can continue to function as a snapshot master even if the source database deployment is deleted. When you create a snapshot master, the source database deployment is put into maintenance status while a copy is taken.

When you create a snapshot clone, Exadata Cloud Service creates another database deployment that references the snapshot master. To record changes in the clone database, Oracle writes altered blocks to the SPARSE disk group without changing the snapshot master. Thus, you can create several space-efficient clones based on the same snapshot master to use for various purposes, including application testing or branched application development work.

Here are the tasks for creating and managing snapshot masters and clones:

Creating a Snapshot Master

Open the Oracle Database Cloud Service console.

For detailed instructions, see Accessing the My Services Dashboard and the Oracle Database Cloud Service Console.
Click the name of the database deployment for which you want to add a snapshot master.

The Oracle Database Cloud Service Overview page is displayed.
Click the Administration tile and then click the Snapshots tab.

The Oracle Database Cloud Service Snapshots page is displayed. Any snapshot masters already associated with the deployment are shown in the Available Snapshot Masters list.
Click Create Snapshot Master and specify the attributes associated with the snapshot master. Then, click Create.
- Snapshot Master Name — enter a name for the snapshot master.
- DB Name — enter a name for the database instances.
- Administration Password and Confirm Password — enter and then re-enter an administration password.
  
  The administration password is used to configure administration accounts and functions in the snapshot master database deployment, including the password for the Oracle Database SYS and SYSTEM users.
  
  Note:
  Ensure that you remember the administration password associated with your snapshot master database deployment.
- Hostnames — specify one or more compute nodes that you want to host the database instances for this snapshot master.
- Description — enter a description of the snapshot master. (Optional)
- ACFS — select this option to use Oracle ASM Cluster File System (ACFS) to store the Oracle binaries for this snapshot master.
  
  Note:
  By using ACFS, you can reduce the amount of local storage space consumed by Oracle binaries on each compute node. However, this option is only recommended for non-production databases on Exadata Cloud Service.
- Clone Source Oracle Home — select this option to clone the existing Oracle Home directory location and binaries into a new Oracle Home location for the snapshot master to use. If you do not select this option, then a new Oracle Home directory location is created and populated with binaries from the current default software image for the corresponding Oracle Database software version.

Listing Clone Database Deployments Created from a Snapshot Master

Open the Oracle Database Cloud Service console.

For detailed instructions, see Accessing the My Services Dashboard and the Oracle Database Cloud Service Console.
Click the name of the snapshot master deployment that you are interested in.

The Oracle Database Cloud Service Overview page is displayed.
Locate the Associations region on the Oracle Database Cloud Service Overview page.

Click the triangular expand icon () before Associations to view the list of clone deployments that are associated with the snapshot master.

If the Associations region is not displayed, no clone deployments have been created from the snapshot master.

Deleting a Clone Database Deployment

Open the Oracle Database Cloud Service console.

For detailed instructions, see Accessing the My Services Dashboard and the Oracle Database Cloud Service Console.
Locate the snapshot clone that you want to delete and choose Delete from that snapshot clone’s action menu ().
In the Delete Service window, confirm that you want to delete the clone database deployment by clicking Delete.

Once deleted, the associated entry is removed from the list of database deployments displayed in the Oracle Database Cloud Service console.

Deleting a Snapshot Master

Note:

You cannot delete a snapshot master that has clone database deployments associated with it. You must first delete the clone deployments, as described in Deleting a Clone Database Deployment.

Open the Oracle Database Cloud Service console.

For detailed instructions, see Accessing the My Services Dashboard and the Oracle Database Cloud Service Console.
Locate the snapshot master that you want to delete and choose Delete from that snapshot master’s action menu ().
In the Delete Service window, confirm that you want to delete the snapshot master by clicking Delete.

If the window warns you that you cannot delete the snapshot master because there are existing clones, click Close and then delete the clones before trying to delete the snapshot master.

Once deleted, the associated entry is removed from the list of database deployments displayed in the Oracle Database Cloud Service console.