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Best Practices for Veeam Backup & Replication 7.0 for VMware

Veeam Management Pack Help Center  > Best Practices for Deployment & Configuration >  Understanding Veeam Backup & Replication Options > How It Works: Backup Methods > Reversed Incremental

Reversed Incremental

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With reversed incremental mode, the first run of a backup job creates a full backup of a VM. VM data is copied block by block, compressed using the selected compression level, and stored in a resulting full backup file (.VBK).

All subsequent backups are incremental, reading only data blocks that have changed since the last job run utilizing VMware’s built-in Change Block Tracking. During the incremental backup, changes are injected into the .VBK file, modifying this file to reflect the most recent state of the virtual machines it contains.

The process also creates a reversed incremental backup file (.VRB). This file contains only the data blocks that were replaced during the incremental run.

The full backup file (.VBK) continues to contain the blocks which represent the most recent backup data, but by overlaying the reversed incremental file (.VRB) Veeam can represent the previous state of the VM as well since that file now contains the older blocks.

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Below are listed some pros and cons of reversed incremental method.

Advantages

Considerations

Uses absolute least amount of space.

Requires significantly more I/O on target storage (1x read, 2x write during backup).

Granular retention (e.g. keep exactly 30 restore points)

Typically slower with dedupe, especially for high change rate VMs.

Allows for forever incremental (no full backups needed)

New backups cannot be run while restores or virtual labs are running.

Not recommended for dedupe appliances because the large .VBK files are changed during every backup, causing the appliance to re-dedupe the file every time.

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