# macOS 27 does not support CoreStorage volumes

- HackerByte page: <https://hackerbyte.net/en/stories/a-developer-issue-regarding-the-compatibility-of-a-new-macos-version-with-an-old-50356944>
- Original source: <https://wadetregaskis.com/macos-27-golden-gate-does-not-actually-support-corestorage-or-hfs-volumes/>
- Hacker News discussion: <https://news.ycombinator.com/item?id=50356944>
- Submitted to Hacker News: 2026-11-03T19:27:53.000Z

A developer issue regarding the compatibility of a new macOS version with an older storage technology.

## AI-generated summary

Apple's latest macOS release, codenamed 'Golden Gate' \(macOS 27\), has effectively broken support for CoreStorage and encrypted HFS\+ volumes. Users can no longer mount, convert, or erase these volumes through standard tools, rendering significant storage hardware useless. While a workaround involving deleting logical volumes and rebooting is possible, it's convoluted and doesn't fully restore functionality.

## Key points

- macOS 27 \(Golden Gate\) no longer supports CoreStorage and encrypted HFS\+ volumes.
- Standard tools like Disk Utility and diskutil fail to mount, convert, or erase these volumes.
- An error dialog misleadingly suggests macOS 28 will be the first unsupported version.
- A low\-level workaround using \`mount\_hfs\` with read\-only access is possible.
- A more involved workaround involves deleting logical volumes and rebooting to enable erasure.