When using Microsoft Azure to run your SAP system, depending on the scenario (such as failure, error, or other use case) the level of restore and recovery is different.
You may need just the virtual machine (VM), database, a few files, or everything. You also need to know your organization’s tolerance for data loss to make recovery decisions. If there is a logical error, then you need an older recovery point than when the error occurred.
Virtual Machine Restore
Depending on whether a VM has encrypted disks, Microsoft Azure Backup has several restore options as shown in the figure below (encrypted disk doesn’t support file-level restore).
Restore can either be in the same region on the original or alternate VM if failure occurred because of corruption, logical error, and so on, or it can be to a Microsoft Azure paired region (if enabled) for disaster events or drills. The cross-region restore feature uses geo-redundant storage under the hood managed by Microsoft Azure Backup. From Microsoft Azure portal, the restore options can be invoked from the backup blade of a VM (or from a recovery vault), as shown in this figure.
Microsoft Azure Backup has the option—called instant restore—to retain the VM snapshot locally up to five days, which significantly reduces the restore time. Instant restore has an impact on storage cost, but the feature can’t be disabled; if you don’t anticipate using this feature, set it to one day to minimize cost.
SQL Server and SAP HANA
Database restores are more involved because you can do point-in-time recovery using logs. For SQL Server as well as SAP HANA, log backups can be done as frequently as 15 minutes. Microsoft Azure Backup understands point-in-time recovery and presents you with an option to do so, as highlighted in the next figure. Similar to the VM restore, there are options to either override the existing database or restore at an alternate location.
Another useful option is Restore as files, which comes in handy when you’re trying to restore the database in a different subscription or region, such as a system copy if your nonproduction systems are in a separate subscription.
Microsoft Azure Backup also supports cross-region restore for both SQL Server and SAP HANA backups.
Testing for all Use Cases
Whether you’re using the same tool across the board for backups or a combination of different tools based on use case, you should test and document the backup, restore, and recovery processes for all the use cases identified in scope.
There may be database-specific steps that you’ll need to perform; for example, if you restore as files for the SAP HANA database, you’ll need to recreate the backup catalog (using SAP HANA executable hdbbackupdiag), which should be documented and operationalized.
For those using third-party tools, refer to the product-specific restore/recovery procedures.
If you're looking to learn about paths to Microsoft Azure for SAP customers, take a look at this blog post.
Editor’s note: This post has been adapted from a section of the book SAP on Microsoft Azure: Architecture and Administration by Ravi Kashyap.