We performed a full backup of a 1 TB Oracle database by using DD Boost software. DD Boost software integrates with RMAN and enables host-based deduplication of database backups to the Data Domain appliance. A full backup eliminates reliance on other backups, simplifying the management of backups and simplifying restoration after an unplanned failure.
In this use case, we used the DD Boost appliance to perform the full backup of the production database. In the tested configuration, we used a LAN connection to the Data Domain appliance, as shown in the following figure.
Figure 33. Use case 1 architecture diagram
The first full backup of an Oracle database is entirely unique; thus, all the data is protected on the Data Domain system. Therefore, the DD Boost software only sends a small subset of information to the Data Domain system for protection. Although the first full backup is unique, when the data has been protected on the Data Domain system, it then is compressed, as shown in the following figure.
Figure 34. Data compression statistics after the backup in Data Domain Appliance
A Data Domain system uses a local compression algorithm developed specifically to maximize throughput as data is written to disk. The default algorithm (lz) allows shorter backup windows for backup jobs but uses more space. Two other types of local compression are available, gzfast and gz. Both provide increased compression over lz, but at the cost of additional CPU load. Local compression options provide a trade-off between slower performance and space usage. It is also possible to disable local compression.
The following figure demonstrates a local compression factor savings that is based on the default algorithm (maximized throughput) on the Data Domain system. There is a relationship between the amount of unique data and the local compression factor: the greater the amount of unique data, the more opportunity for compression and the higher the compression factor. For example, the first backup consists of entirely unique data and has the largest compression factor. The following figure illustrates the compression.
Figure 35. Database server size and Data Domain backup comparison
This compression saves significant space on the Data Domain system. Dell EMC engineering test results show that the compression factor was 1.4X: that is a 40 percent space savings for the full backup. The 1 TB Oracle RAC database was backed up in 36 minutes to the Data Domain system. Because this backup was the first full backup and all the data is considered unique, the backup time shows the capability of the business to protect databases quickly with the Data Domain system.