Veeam backup methods and the impact on destination storage I/O

Veeam Backup & Replication allows users to choose among several different backup methods to fit their need. Each method has its own strenghs and weeknesses, and there is always a tradeoff between used space on the backup storage and the amount of activity (both from the cpu and the IOPS generated on the storage) required to complete the backup.
However, backup designers often evaluate only the used space, keeping low attention on the impact each chosen method has on destination backup I/O. This is fundamental in the choice of the backup appliance so that backup times do not go over the desired backup window.
We will analyze in this paper the available methods and their pros and cons. We will assume standard disk storage is used; different analysis may be required if deduplication storage appliances or other different systems are used.