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Received — 22 July 2026 ⏭

Sunsetting CoreStorage

✇Michael Tsai
By: Michael Tsai
14 July 2026 at 19:26

Apple:

In macOS 28 and later, the Mac OS Extended file system format will be supported only for volumes (disks and other storage devices) that aren’t encrypted. For future macOS compatibility, either decrypt or reformat any encrypted Mac OS Extended volumes.

I think Apple removed the user interface for creating such volumes way back in Big Sur. It’s not really surprising that they’re going away, although only offering a year of warnings seems rather aggressive. Many people delay updating to major OS versions or wait until they get a new Mac. There will be users that switch to a Mac that can only run macOS 28 and get rid of their old one before realizing that some drive they haven’t connected in a while won’t mount.

The other surprising part is that Apple’s options—reformat or decrypt—are not great. During the initial transition to APFS, macOS would transparently convert an encrypted HFS+ boot volume to encrypted APFS without rewriting any data. This functionality is nominally still available via the diskutil apfs convert command, but Apple hasn’t mentioned this or built an automatic upgrader GUI.

[Decrypting] doesn’t apply to encrypted Time Machine backup disks.

It’s obvious why. The old Time Machine format with hard links is totally different from the new one based on APFS snapshots. But this means that you’ll either need to buy a new Time Machine drive for use with macOS 28 or delete your backup history. Even if you keep the old drive, you’ll need an older boot drive or an old Mac in order to be able to access it.

Previously:

Update (2026-07-24): Marcus Mendes:

Apple has now revised the page to add a third option, allowing users to convert an encrypted HFS+ volume directly to encrypted APFS without decrypting it first.

[…]

The company has also removed its previous instructions for decrypting the volume first, converting it to APFS without erasing it, and then optionally re-encrypting it.

Hammer:

Ignore Apple’s guidance and do not use Convert to APFS in Disk Utility for disk images.

The first encrypted HFS+ disk image I tried to convert that way failed and left me with an unusable disk image. If I didn’t have backups I’d have lost its contents.

It didn’t corrupt the disk images that I tried, but it didn’t work, either, instead failing with an error about expecting a GPT partitioning scheme.

Update (2026-07-28): Howard Oakley:

As encrypted disk images have never used CoreStorage, withdrawal of support for that has no impact on the continued use of any form of encrypted disk image, including those using HFS+ as their virtual file system.

This is a good point. Apple’s support page refers to “encrypted Mac OS Extended disks,” but the developer release notes refer to CoreStorage specifically. So this shouldn’t affect most encrypted disk images, which show up in Finder as unencrypted after mounting. The encryption is at the disk image level rather than at the file system level. However, I’m not sure that all encrypted disk images are safe. Presumably, a device image, which directly copies the blocks rather than the files, would still use CoreStorage.

Searching Time Machine Backups and Versions

✇Michael Tsai
By: Michael Tsai
9 July 2026 at 19:38

Howard Oakley:

Spotlight doesn’t currently appear able to search Time Machine backups reliably, at least not in Sequoia or Tahoe, although this may not be universal.

[…]

If I now step back through my backups to reach one that I know contains that file, I can restore it. But if I type anything into the search field, nothing is found. If I change the scope of the search to that backup, the window title changes but its contents remain blank, and there isn’t even a busy spinner to indicate a search is in progress.

[…]

As I can’t disable Spotlight indexing on that volume without macOS telling me that it’s required to be indexed by Spotlight, neither can I force that volume to be reindexed.

[…]

My conclusion is that using Spotlight to search Time Machine backups no longer works, and the instructions given by Apple are also broken.

That has been my experience, too. As I see it, there are four separate problems:

  1. I want to be able to search all my backup snapshots, because I don’t know which one might contain the file I want to restore. Time Machine only lets you search one at a time.
  2. Searching an individual snapshot doesn’t actually work.
  3. Spotlight indexing is invasive, using lots of CPU time, and with spinning hard drives causes wear and tear and creates lots of noise. If search doesn’t work anyway, I’d like to turn it off, but macOS won’t let me.
  4. If the problem is with the index, there’s no way to reset it without deleting your backup.

Howard Oakley:

Unfortunately, all those saved versions in the version database fall outside the scope of Spotlight indexing, and Spotlight search can’t look inside any of the old versions saved in a volume’s version database. Surprisingly, the version browser doesn’t offer any search facilities either, as that’s presumably another feature intended for a future that never came.

[…]

One way around this is to save each document version as a separate file, allow Spotlight to extract their contents and add those to its indexes for that volume, then to search those files. This is quick and simple using my free utility Versatility.

Previously:

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