Data Domain compression calculations compare the amount of data that is received to data that is already stored on disks. Duplicate data from the host does not need to be stored again, while new data is locally compressed before being written to disk. Our results show that the first complete backup achieved a compression savings of approximately 201 MB (1,330 - 1,129) on Data Domain.
The following figure shows our Data Domain compression findings.
Figure 6. Data Domain compression findings for the Ready Node for SAP HANA
Because SAP HANA achieves higher data compression with columnar tables, the initial backup does not show significant savings. The space savings are substantial for the second and third backups because the client-side deduplication provides the Data Domain compression. The second full data backup takes up 81 MB and the third backup takes up 62 MB on the Data Domain system.
In all three tests, the Dell EMC engineers used full data backups of the SAP HANA database. Working with full backups is a benefit to the organization because they are faster to restore than a combination of full and incremental jobs. Full backups have no dependency on prior backups. Restores are faster because the database only has to read from the full backup and not from prior backups. The capability to perform a full database backup and take a minimum amount of space on the Data Domain system means that the organization can keep more backups online without having to archive data.