How Data Integrity is Ensured in Compute Engine across Multiple Locations

Correct Answer: B.

Option A is incorrect.

Snapshot can be created from disks when attached to a running VM.

Hence, this statement is incorrect.

Option B is correct.

Snapshot data integrity is ensured by automatic checksum.

Option C is incorrect.

Snapshot data integrity is ensured by automatic checksum.

Hence, the state of the VM is not a concern.

Option D is incorrect.

Snapshot data integrity is ensured by automatic checksum.

Data is incrementally backed up from disks.

https://cloud.google.com/compute/docs/disks/snapshots

The correct answer is B. By automatic checksum.

Compute Engine is a cloud computing service offered by Google that allows users to create virtual machines (VMs) and store data on Google's infrastructure. When using Compute Engine, users can create snapshots of their VMs, which are essentially point-in-time copies of the VM's disk data.

To ensure data integrity of the snapshots, Compute Engine uses an automatic checksum. A checksum is a mathematical algorithm that calculates a unique value for a piece of data, such as a file or snapshot. When a snapshot is created, Compute Engine calculates the checksum of the data and stores it alongside the snapshot.

When a user retrieves a snapshot, Compute Engine calculates the checksum again and compares it to the stored checksum. If the two checksums match, then the snapshot is considered to be valid and the data is considered to be intact. If the checksums do not match, then the snapshot is considered to be invalid and the data may be corrupted or tampered with.

By using an automatic checksum, Compute Engine ensures that the data integrity of the snapshots is maintained. This helps to prevent data loss and ensures that users can retrieve their data in the event of a disaster or other data loss event.

Option A, by making sure that the snapshot is created only when VM is not running, does not necessarily ensure data integrity, as the VM's data could still be corrupted or tampered with while it is running.

Option C, by making sure that the snapshot is created only when VM is running, is not possible, as snapshots can only be created when the VM is stopped or paused.

Option D, by disabling incremental backup, is not directly related to data integrity, but rather relates to how Compute Engine handles backup data. Incremental backup is a method of backing up only the data that has changed since the last backup, which can help to reduce the amount of data that needs to be backed up and stored. However, disabling incremental backup would not necessarily improve data integrity.