Dissecting Apple’s Sparse Image Format (ASIF)
ASIF takes a lot of inspiration from existing virtual disk formats. Practically, that means it’s another sparse virtual disk format, and functions very similar to sparse VMDK, VHDX or QCOW2 files (for the uninitiated, it allow you to store a large disk, or file, in a smaller, “sparse” manner).
Shortly before the release of macOS Tahoe (late 2025), I thought it’d be a fun exercise to try and write a parser for ASIF files.
Previously:
