Before backing up data using the dump command, you must have a clear idea of how much data you will be backing up and how many tapes you will need to store the data.
Determining the amount of backup data
Before you enter the dump command, it is helpful to estimate the amount of backup data so that you can determine the number of tape files and the number of tapes required for the backup.
Estimating the number of tapes for the backup
You must estimate the number of tapes required for the backup before executing the dump command. This estimate helps you to ensure that the dump command does not fail because it runs out of tapes. It also helps you to load the required number of tapes in the tape drives or libraries in advance for an unattended backup.
Scalability limits for dump backup and restore sessions
You must be aware of the maximum number of dump backup and restore sessions that can be performed simultaneously on storage systems of different system memory capacities. This maximum number depends on the system memory of a storage system.