The following example shows how a database backup may run under normal conditions:

• Backup devices:

The database backup is carried out onto locally mounted tape units. The DAT DDS-2 disk drives are used presently with hardware compression. Ten tape units are available in our example.

• Throughput:

The throughput of the backup is about 2 GB per hour.

• Tape capacity assuming 120 meters of tape:

• about 2.4 GB for tape units without hardware compression
• about 7 GB for tape units with hardware compression (assuming the average compression rate for SAP data: about 3-4)

• Time window:

The backup should be possible in less than 10 hours overnight.

• Size of the database:

The size of the database is 100 GB.

If the database can be backed up in parallel to ten tape devices, then it can be made within ten hours (with hardware compression).