Dissecting Apple's Sparse Image Format (ASIF)

At WWDC 2025, Apple announced macOS 26 Tahoe. One of the new features in macOS Tahoe is a new disk image format: ASIF. Designed for use with virtual machines (its documentation lives under the Virtualization framework ), ASIF takes a lot of inspiration from existing virtual disk formats. Practically, that means it&rsquo;s another sparse virtual disk format, and functions very similar to sparse…