Azure VM Backup Taking Longer Than Expected

Question

I am taking backups of my Azure VM using Azure Recovery Service Vault. When I checked the backup recovery points, I noticed that it's taking a time up to 4 to 5 hours, but initially, it only took a snapshot for 10 minutes. It is a scheduled backup that runs once a day during off-hours

By getting it's more details have noticed it is taking time in Transfer data to vault

What is difference between Snapshot and Transfer Data to Vault?
Is this the default behavior, or could there be a specific reason for this duration?

Answer 1

What is difference between Snapshot and Transfer Data to Vault? Is this the default behaviour, or could there be a specific reason for this duration?

While taking the Backup of VM to Recovery Service Vault contains two stages

1.Snapshot ensures the availability of a recovery point stored alongside the disks, making it suitable for Instant Restores. These snapshots remain accessible for up to five days, depending on the user's configured snapshot retention settings.

2.Transfer data to vault : During the Transfer data to vault phase, a recovery point is established within the vault for long-term retention. This phase initiates only after the completion of the snapshot phase

At the backend, two Sub Tasks are in progress—one for the front-end backup job, which can be viewed in the Backup Job details pane as shown below

The completion time of the Transfer data to vault phase may be lengthy, influenced by factors such as disk size, churn per disk, and various other considerations.

Reference: Back up Azure VMs in a Recovery Services vault