Whether it’s through reconfiguration or redeployment, either by a person or an automated process, Change History allows you to easily find what changed to Azure Resource Manager Resources.
This feature is a Public Preview, meaning it is as-is with no Service Level Agreements and limited warranty. Microsoft also may choose not to release a Preview into “General Availability”.
Change History can be useful for CMDB purposes where you only get the incremental changes to resources on a frequent basis instead of the full resource details. Another case could be during incident management. A VM has rebooted unexpectedly, but during investigation Change History allowed you to find out the VM size had been changed during the incident window.
For the VM named AZF-VM-CHISTORY we need to know what caused a reboot between 9:30PM and 9:45PM. While in the Azure Portal we open the Activity Log, which we filter for this specific VM and time range.
From there we can see events that happened during this time range and we can open the required event.
Once opened we can select “Change history (Preview) and find changes that happened in the last 14 days.
This view shows you exactly what has changed, when it changed and it’s old (left) and new state (right). In this case the VM size had changed from a medium sized VM (B8ms) to a small sized VM (D2S V3).
Although it’s still a preview feature it’s a nice little feature which has many benefits including but not limited to change tracking and incident handling.