Using Delphix as a Backup Solution to SQL Server
If you use a backup solution that is not supported by Delphix, you cannot use your existing backups to keep your dSources in sync. However, enabling Delphix Managed Backups will overcome this issue by using automatic copy-only full backups to keep dSources in sync. Currently, dSources linked when this feature is enabled will not support LogSync functionality, which means that you can only provision VDBs from snapshots and not from any time between snapshots. Additionally, in the current release, the Delphix Engine cannot take differential or transaction log backups of the source database.
Linking SQL Server dSources with Delphix Managed Backups
It possible to enable this feature here at link time or toggle it on after the link for future syncs. If you enable this feature, the dSource can only use copy-only full backups taken by the Delphix Engine to stay in sync with its source; the Delphix Engine will prohibit syncing using existing backups. Checking the Enabled box results in the following changes to the Data Management page:
- The initial load option is set to a copy-only full backup taken by the Delphix Engine
- The ability to provide a backup path disappears
- A SnapSync policy selection screen appears in the Policies page
You can select from the list of existing SnapSync policies, if the one you want doesn't exist you will need to create a new one on the Policies page under the Manage dropdown. Proceeding through the remainder of the link wizard will create a dSource with Delphix-managed backups enabled. You can confirm that a dSource has the feature by selecting the dSource and going to the Configuration > Data Management tab after creation and checking the Delphix Managed Backups section, as displayed below:
To disable / enable this feature after linking:
Toggling Delphix Managed backups is supported for SQL Server dSources. This means a dSource that was previously created with Delphix Managed Enabled can have regular validated sync and similarly a dSource that had external backups can use Delphix Managed Backups.
To disable Delphix Managed Backups for a specific dSource, select that specific dataset and go to Data Management tab under the Configuration tab.
Click the edit button and uncheck this feature. Then update all new inputs.
To enable this feature just go to the same edit menu.
Delphix Managed Backups on Secondary Nodes of AlwaysOn Availability Group Cluster
They can pick one of the following options that describe their backup policy as shown below.
Primary (default option): Backups are taken only on primary node.
Secondary Only: Customers who never want to use primary for their backups must choose this option as it ensures backups never go to the primary node. If the secondary nodes are down, the backups fail but do not use primary at all.
Secondary preferred: As the name suggests, one of the secondary nodes is used for backup. The backup will be taken on primary if none of the secondary nodes can be used for backup. So, customers who want reliable backups even if they are taken on primary node if required should use this option.
Backup policy can be changed after dSource creation too as shown below.
Backup policy is not only provided during the linking phase of a dsource but also during the manual snapsync phase too to provide more flexibility to customers as shown below. Default option is the Backup Policy selected during linking phase.
Understanding SnapSync Policies
- Click Manage.
- Click Policies.
Check SnapSync Policy
For dSources that have Delphix-managed backups enabled, the current SnapSync policy will be displayed under the SnapSync column. The rows corresponding to dSources that do not use Delphix Managed Backups will be grayed out. Clicking the current SnapSync policy for a dSource will display a drop-down menu of existing SnapSync policies along with the option to create a new SnapSync policy. Selecting a SnapSync policy from this list will change the current SnapSync policy for the dSource. When creating a new policy, you will see the following screen:
Create New SnapSync Policy
Here, you can configure the frequency with which the Delphix Engine takes backups of your source database. You can modify these schedules at any time by clicking the Modify Policy Templates button in the upper right-hand corner of the policy management screen.
The Timeout field above specifies how long a SnapSync job is allowed to run before it is terminated. If a SnapSync job exceeds its timeout window, the Delphix Engine discards the new backup and rolls back the dSource to the most recent snapshot.