AZ-104 Certification Notes

Chapter 10.4 - Managed Disk Snapshots Managed Custom Image

Managed Disk Snapshots and Managed Custom Image

A managed disk snapshot is a read-only crash-consistent full copy of a managed disk that is stored as a standard managed disk by default.

• Snapshots are point in time recovery
• Snapshots exist independent of the source disk and can be used to create new managed disks
• Snapshots are billed based on the used size. (If you have a 64 GB drive and only use 10 GB you're only billed the 10 GB)
• You can see the used size of you snapshots by looking at the Azure usage report A managed custom image allow you to create an image (a copy) of your disk from you VM. This image contains all managed disks associated with a VM, including both the OS and data disks.

A snapshot doesn't have awareness of any disk except the one it contains. This makes it problematic to use in scenarios that require the coordination of multiple disks, such as striping.

Snapshots would need to be able to coordinate with each other and this is currently not supported. This is where you would want to use a Managed Custom Image.

Practice Quiz

• What is true about a managed disk snapshot?

  • Snapshots are billed based on the used size.
  • You can see the used size of your snapshots by looking at the Azure usage report.
  • All of the options
  • Snapshots are point in time recovery
  • Snapshots exist independent of the source disk and can be used to create new managed disks

• What is a read-only crash-consistent full copy of a managed disk that is stored as a standard managed disk by default?

  • A managed disk snapshot

• What is a managed custom image?

  • A managed custom image allows you to create an image (a copy) of your disk from your VM. This image contains all managed disks associated with a VM, including both the OS and data disks.