Determining FETB for workloads
The Front-End Terabytes (FETB) is the amount of data protected by NetBackup. Note that this is not the space allocated to clients, but the size of the data that NetBackup will protect. For example, a VMware virtual machine may have an 80 GB VMDK, but only 25GB is used, and after swap and paging files are excluded NetBackup reports 21 GB as the size of the backup. For sizing, 21 GB should be used as the FETB.
Database transaction logs need to be handled differently than other workloads, since the change rate for each backup will be 100%. For transaction logs, determine the total volume of logs that will be protected during the retention period.