Describing Backup and Recovery

The normal database backup and recovery principles apply to SAP HANA. The SYSTEMDB and all tenants are separate databases, which can be individually backed up and restored. SAP HANA supports the following backup and recovery capabilities:

• Complete, differential, and incremental backups
• Automatic redo log backups
• Integrity checks for backups
• Backup lifecycle management
• Recovery to the most recent state, a specific point-in-time, or a specific data backup
• Backup and recovery using third-party tools
• Database copy using backup and recovery

With the tools SAP HANA cockpit, hdbsql and the ABAP transaction DBACOCKPIT, you can create backups manually or schedule backups.

Data and log backups are performed while the SAP HANA database is online. The performance impact of backups on system performance is negligible, and users can continue to work while the data backup is running.

The file system backup location for data and log is specified system-wide, and must be valid for all nodes of the SAP HANA system. Both the data and the log location should be located on external media.

The parameter basepath_databackup holds the location where the data backups are written. By default, the location for data backup files is $(DIR_INSTANCE)/backup/data. If you change the backup location in basepath_databackup, the change occurs immediately.

Backups of tenant databases are always created in sub-directories of basepath_databackuplocation.

The automatic log backups are written to the location mentioned in the parameter basepath_logbackup.

Integrity tests are performed while the database backup is running. If these checks are successful, the data is written to the backup destination. The data areas of all running SAP HANA services are individually backed up, these backup run in parallel. This is also true for an SAP HANA scale-out system were all data areas of all services on all hosts are backed up in parallel.

A complete data backup includes all the data that is required to recover the database to a consistent state. This includes both business data and administrative data. In a data backup, only the actual data is backed up; unused space in the database is not backed up. A data backup reflects the consistent database state from the time at which the data backup was started.

The system database plays a central role. It can initiate backups of both the system database itself and of individual tenant databases. A tenant database can create its own backups without the need to connect through the system database. System database and tenant databases have their own backup catalogs.

By default, the configuration files are not part of a data backup. If required, the data backup can easily be configured to include the configuration files.

In a recovery situation, configuration files can help to identify and restore the customer-specific changes. The configuration files are not essential to perform a recovery. If you want to use a customer-specific configuration, reconfigure the recovered system using the SAP HANA cockpit.

To ensure data security, it is necessary to perform data and log backups at appropriate intervals. We recommend that you perform:

• Daily a complete data backup, or at least once a week, in a 4-week backup cycle
• Daily a delta data backup (incremental or differential) during the week
• Daily automatic log backups

This creates four backup generations in a 28-day cycle. After the 28 days, the backup media can be reused.

Depending on factors such as database size, availability of backup destination, and other factors, you can define a suitable backup strategy.

You can use a simple backup strategy consisting of regular complete database backups and log backups. To recover from a media error (disk), you restore the database from a complete data backup (preferably from the last one), recover log backups written during and after this backup, and recover the most recent log entries from the log area to completely recover the database.

In a system where delta backups can reduce backup time, you can perform complete backups less often and replace them with delta backups. To recover from a media error (disk), you restore the database from a complete data backup (preferably from the last one), recover the necessary delta backups, recover log backups written during and after this delta backup, and recover the most recent log entries from the log area to completely recover the database.

The configuration of backup settings (for example, data and log backup destination paths, log mode, backup retention time) is available in the backup configuration application of SAP HANA cockpit 2.0. Most configuration parameters are configured systemwide, but depending on the backup strategy, some backup configuration setting should be adjustable per tenant.

Per tenant, the backup retention policy can be configured so that it matched the backup strategy. The data backup destination can also be adjusted per tenant, but this can be blocked from the SYSTEMDB setting. To restrict data backup path changes, in the Backup Configuration (Systemwide) application, set the Users Have Free Choice of Backup Destination switch to No. This disables backup destination path changes for the complete SAP HANA database system. To disable the backup destination path on a specific tenant, use the Restricted Features application, and for the tenant, uncheck the IGNORE_PATH_RESTRICT parameter with the description Ignoring of path restrictions for Backup Operations.

From the SYSTEMDB, the backup configuration lets you configure settings that apply to the whole SAP HANA database system. The systemwide backup configuration application allows you to change the following:

• Catalog settings

• Log settings

• Data Backup

• Retention Policy

• Restrictions for Tenant Database Users

From a tenant database, the backup configuration lets you configure settings that apply to that specific tenant database only.

In large SAP HANA systems, data backup files might be larger than the maximum file size that can be stored on the respective file system. The configuration options allow you to specify the maximum file size for backup files. If a backup exceeds this size, it is split into several files.

Backup and recovery operations can only be performed by users that have the appropriate authorizations. The authorization required depends on whether administrative tasks are performed at SYSTEMDB level or at tenant database level.

The table shows the available backup and recovery system privileges with a short description of each.

To be able to perform the different backup, recovery, and configuration tasks in SAP HANA Cockpit or using native SQL requires different sets of system privileges. The combinations of required system privileges also depends on the administrator role (admin or operator). The SAP Online Documentation provides a good overview on the System privileges needed to perform different backup and recovery tasks.