Hyper-V RCT

Hyper-V RCT - Enhanced Backup and Recovery Performance

What is Hyper-V RCT?

Hyper-V RCT (Resilient Change Tracking) is a native mechanism within the Hyper-V architecture designed to track changes in the disk blocks of virtual machines (VMs). This feature is akin to Changed Block Tracking (CBT) in VMware and represents a significant leap forward in managing data backup operations. RCT enables incremental and differential backup processes to be more efficient by directly providing the list of changed blocks since the last backup. This bypasses the need for traditional, time-consuming methods of comparing current VM disk blocks with those in existing backups to identify changes.

Use Cases:

• Incremental Backups: RCT is particularly beneficial for incremental backups where only the changes since the last backup need to be captured. This can significantly reduce the backup window and storage requirements.

• Differential Backups: For differential backups, which capture all changes since the last full backup, RCT provides a straightforward method to determine the necessary data, simplifying and accelerating the backup process.

How Does It Work?

RCT operates by maintaining a change tracking log for each virtual disk attached to a VM. This log records blocks that have been modified since the last backup. When a backup operation is initiated, RCT provides a list of these changed blocks to the backup software, which then only needs to copy these blocks. This mechanism is continuously updated with every backup, ensuring that each subsequent backup is both fast and efficient.