Virtual disk storage techniques

A method for managing a virtual disk of a virtual machine, the method comprising:

• receiving, from a guest operating system of the virtual machine, a signal indicating that a portion of a virtual disk extent of a virtual disk is no longer in use, wherein the virtual disk is stored in a group of virtual disk files comprising a child virtual disk file and a parent virtual disk file;
• identifying a portion of a virtual disk file of the group of virtual disk files that describes the portion of the virtual disk extent;
• and
• sending a request to trim the identified portion of the virtual disk file to a file system that stores the virtual disk file.

A system, comprising:

• at least one processor;
• and
• memory storing instructions that, when executed by the at least one processor, cause the system to perform a set of operations, the set of operations comprising:
• receiving a request for data of the virtual disk;
• identifying, based on state information associated with the virtual disk:
• a first virtual disk extent corresponding to the request for data, wherein the first virtual disk extent is stored in a child virtual disk file;
• and
• a second virtual disk extent corresponding to the request for data, wherein the second virtual disk extent is stored in a parent virtual disk file of the child virtual disk file, and state information of the child virtual disk file indicates a transparent state for the second virtual disk extent, thereby indicating the parent virtual disk file stores the second virtual disk extent;
• and
• providing, in response to the request for data, data from the first virtual disk extent of the child virtual disk file and data from the second virtual disk extent of the parent virtual disk file.