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Crash-Consistent Backup

In this article

    Crash-consistent backup is Veeam’s method of creating crash-consistent VM images. A crash-consistent image can be compared to the state of a VM that has been manually reset. Unlike offline backup, crash-consistent backup does not involve any downtime.

    Crash-Consistent Backup Important!

    Crash-consistent backup does not preserve data integrity of open files of transactional applications on the VM guest OS and may result in data loss.

    Crash-consistent backup is performed in the following way:

    1. Veeam Backup & Replication interacts with the Hyper-V host VSS Services and requests backup of specific VMs.
    2. The Hyper-V host VSS Writer notifies the VSS provider that volume snapshots can be taken.
    3. The Hyper-V host VSS provider creates a snapshot of the requested volume.
    4. The volume snapshot is presented to Veeam Backup & Replication. Veeam Backup & Replication reads VM files from the volume snapshot using one of two backup modes — on-host backup or off-host backup. After the backup is completed, the snapshot is deleted.

    Crash-Consistent Backup