Apple Deprecates hdiutil in macOS 27, and the Replacement Isn't Ready

The macOS 27 Golden Gate beta marks the command-line disk-image tool hdiutil as deprecated, steering users toward diskutil image for attach, create, resize, info, and passphrase operations. diskutil is also the only tool that supports Apple’s new Sparse Image Format (ASIF). Most hdiutil options survive under new names, but several are gone, including -puppetstrings (machine-parsable progress output) and a handful of create -srcfolder flags such as -scrub, -atomic, and -crossdev.

Testing a daily home-folder backup exposed rough edges in the replacement. diskutil was notably faster (roughly 40-45 seconds versus 110-115 for hdiutil) and produced a slightly smaller encrypted DMG, but it failed opaquely on a root-owned file: where hdiutil raised an authentication prompt and continued after admin credentials, diskutil just returned “Operation not permitted” with no useful detail despite verbose mode, forcing the file to be deleted. It also silently scrubs temporary files (dropping ~/.Trash) with no way to disable the behavior, since the -noscrub option no longer exists.

The author argues there’s little justification for retiring hdiutil when the same functionality persists in diskutil, warning that the change risks breaking longtime scripts and third-party apps like Knox that call hdiutil directly. A separate, still-unfixed bug involving inaccessible .bnnsir files affects both tools in the beta — and Apple’s response to the filed report was to ask for an iOS sysdiagnose to diagnose a macOS problem.