Another means of reducing the size of a backup file is compression. Use of compression decreases the size of created backups but affects duration of the backup procedure.
Veeam Backup & Replication allows you to select one of the following compression levels when configuring a backup job or a replication job:
•None - this option is recommended if you use storage devices with compression and/or de-duplication tools to store created backups.
•Dedupe-friendly — this is an optimized compression level for very low CPU usage and uses a very simple, fixed dictionary. This method can be a good compromise when using deduplicating storage or WAN accelerators because, while it will lower the dedupe ratio compared to no compression, it will send less data to the deduplicating appliance.
•Optimal — this is the recommended compression level providing the best ratio between the size of a result file and time of the backup/replication procedure.
•High — this level provides additional 10% compression level over Optimal at the cost of approx. 10x CPU usage.
•Extreme — provides the smallest size of a backup file but will reduce backup performance if there are not enough hardware resources to keep up. In general, this mode will create a backup file that is at most 3% smaller that High compression while using 100% more CPU resources. So, if you intend to use this compression level, it is recommended that you install Veeam Backup & Replication on computers with modern multi-core CPU (at least 8 cores per concurrent job is recommended). This method can be useful for backup/replication across slow WAN links where bandwidth is at a premium and the higher CPU will not be as impactful.