Preparing to use the dump command

Determining the amount of backup data

About 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.

Note
This method of estimation works only for full backups of volumes. It is impossible to determine how much data is being backed up in an incremental backup.

Estimating the amount of backup data in a volume

To estimate the amount of data in a full backup, complete the following steps.

Step	Action
1	For each item that you want to back up, enter the following command: df path_name path_name is the name of the item.
2	For multiple items, such as multiple volumes, add up the data for each item to determine the total amount of data to be backed up.

Step

Action

For each item that you want to back up, enter the following command:

df path_name

path_name is the name of the item.

For multiple items, such as multiple volumes, add up the data for each item to determine the total amount of data to be backed up.