Method for backing up a Photos Library using Disk Utility

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Level 4

1,248 points

Method for backing up a Photos Library using Disk Utility

I've recently adopted a new method for backing up a Photos Library that relies on generating a disk image. Here are the steps:

Select the Image from Folder

Navigate to the parent folder of the Photos Library

Select the disk image options

I've verified the above method several times without issue. In my view, it's an efficient and reliable alternative for backing up a Photos Library especially to networked storage. Once the backup is restored, depending on your usage, you may need to re-enable Photos application settings (e.g. Use as System Photos Library and Shared Albums). Also, please be aware that the replaced Photos Library will be automatically re-indexed. This can take days depending on the size of the library.

Although the disk image is read-only, it is still possible to use the Photos application's import command to access the contents of the backup. Conveniently, this function seems to work across versions of macOS (both backup and forward compatibility). Also, Photos will flag duplicate images which are already present in the current library.

Test Configuration

Photos Library: ~65 GB, 19000+ photos, 30+ videos

Main system: M2 Mac mini (2023) running Tahoe 26.2 with Samsung T7 external SSD hosting the Photos Library

Media server: i5 Mac mini (2018) running Monterey 12.7.6 with Samsung T5 external SSD with File Sharing enabled for hosting the disk image

Network configuration: Point-to-point ThunderBolt Bridge (systems must be close together due to cable length requirements)

Disk Utility image type: Read-only image (UDRO)

- Pie Lover

Mac mini (M2, 2023)

Posted on Jan 29, 2026 2:22 PM

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Answer 1

Jan 30, 2026 8:48 AM in response to BlueberryLover

Disk image is a great tool! It's interesting that you are including the entire Pictures folder.

For backup, Time Machine provides incremental backups that can be done hourly, or at any interval you like. Since I use a MacBook, I carry a tiny, 1 ounce, SSD with me and plug it in from time to time, and zip, it's done. Some use apps like CarbonCopyCloner to do the same thing.

Most of us also periodically just drag the Photos Library from the Pictures folder to an external drive. If the drive is formatted in APFS, then we can actually use the old copy directly.

For a laptop with a limited internal storage, many are using "Optimize Storage, and copying the Photos Library does not provide a backup at all. In that case, you can do this:

Backup iCloud Photos with an Optimized Mac

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Answer 2

BlueberryLover Author

Level 4

1,248 points

Jan 30, 2026 9:33 AM in response to Richard.Taylor

Thanks for the reply. In my case, I'm not using an iCloud Photos Library but rather one that located locally on an external SSD. For extra security, I prefer the library backup to reside on a separate machine which shares a fast network connection.

This approach has an advantage that it addresses both efficiency and security. Still, I periodically use the direct copy method to an SSD that's normally connected to another computer. Interestingly, the direct copy is actually slower than moving the disk images over a network connection. This is because the Photos Library is actually a container with a large number of individual files (over 100000 in my case) which makes copying the original library less efficient than single file DMG.

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Answer 3

BlueberryLover Author

Level 4

1,248 points

Jan 31, 2026 3:35 AM in response to BlueberryLover

I augmented the Automator script to move the disk image directly to the remote server. For some reason, the data transfer rate is slower in this direction. Backup of the 65GB Photos Library, including disk image generation, took about 20 minutes (as opposed to a total of about 12 minutes when the copy is initiated from the server).

Using the script, the backup averaged under 20 seconds per GB of the Photos Library. This is about 3 times faster than simply copying the Photo Library itself.

- Pie Lover

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Answer 4

BlueberryLover Author

Level 4

1,248 points

Jan 30, 2026 12:37 PM in response to BlueberryLover

In case anyone is interested, below is an Automator script as an alternative to using the Disk Utility.

- Pie Lover

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