Duration of the Backup 
Duration of the Backup
Backups often take a great deal of time. For example, if you use DAT tape devices as a backup medium, you can back up 500-1000 MB per hour (without hardware compression) or 1000-2000 MB per hour (with hardware compression). This means that backing up a 10 GB database on one tape device of this type would take approximately 10 hours.
Parallel Backup
You can solve this problem by performing data backups in parallel. If you have several backup devices, you can make a parallel backup with BRBACKUP by assigning several tape devices to the
init<DBSID>.sap parameters tape_address and tape_address_rewind or several disks to parameter backup_root_dir . You can then make a backup of, for example, a 20 GBbyte database in parallel on 5 tape devices in 5 hours. Parallel BackupLogical Volumes
If you are using the logical volume manager, a logical volume is considered to be one disk. Therefore, you should not distribute a logical volume over several physical disks when this is not absolutely essential. This increases the effectiveness of the BRBACKUP minimization of read/write head movement on the disk.
Backup on disk
One interesting way to reduce the backup time is to back up to disk (
backup_dev_type = disk ). These backups can then be copied from disk to a volume (tape, for example), using UNIX utilities ( tar, cpio). This later copy operation could be treated with lower priority Two-Phase Backup tape_copy_cmd.