Virtual machine change block tracking

A system configured to track modified data sectors of a virtual hard disk, the system comprising:

• one or more devices comprising one or more processors, wherein the one or more processors are configured to:
• receive a first write operation generated by a virtual machine to store data in a first sector, wherein the virtual machine (VM) is executed using a hypervisor and comprises a virtual hard disk file;
• determine an identity of the first sector based on the first write operation;
• record that data in the first sector has changed;
• receive an instruction to execute an incremental backup operation of the virtual machine,
• wherein the instruction to execute the incremental backup operation was initiated according to a schedule specified in an information management policy assigned to the virtual machine,
• wherein the information management policy comprises a set of parameters for performing backup operations on data assigned to the information management policy;
• and
• in response to receiving the instruction to execute the incremental backup operation:
• determine that changes to the virtual hard disk file are accurately reflected, execute the incremental backup operation, and
• upon completion of the incremental backup operation of the VM, generate a change block data structure to track disk changes made after the incremental backup operation was initiated.