Mac OS 26 – Tahoe – introduces a new disk image format

Disk images have been valuable tools marred by poor performance. In the wrong circumstances, an encrypted sparse image (UDSP) stored on the blazingly fast internal SSD of an Apple silicon Mac may write files no faster than 100 MB/s, typical for a cheap hard drive. One of the important new features introduced in macOS 26 Tahoe is a new disk image format that can achieve near-native speeds: ASIF, documented here.

macOS Tahoe brings a new disk image format – The Eclectic Light Company

https://eclecticlight.co/2025/06/12/macos-tahoe-brings-a-new-disk-image-format/

TIL: disk images had write speed bottlenecks. I suspect they made these improvements because of their path to support containerization.

Conclusions

• Where possible, in macOS 26 Tahoe in particular, VMs should use ASIF disk images rather than RAW/UDRW.
• Unless a sparse bundle is required (for example when it’s hosted on a different file system such as that in a NAS), ASIF should be first choice for general purpose disk images in Tahoe.
• It would be preferable for virtualisers to be able to call a proper API rather than a command tool.
• Keep an eye on C-Command’s DropDMG. I’m sure it will support ASIF disk images soon.

Exciting.

#containerization #containers #diskImages #mac #macOs #osX

Unregistry – "docker push" directly to servers without a registry

https://github.com/psviderski/unregistry

#HackerNews #Unregistry #docker #push #servers #registry #DevOps #Containerization #GitHub

For my container friends - I'm looking to be able to work on containers locally without an Internet connection.

Docker Desktop failed miserably this morning.

Podman is the next thing that comes to mind because I see it mentioned with dev containers as well.

Should I try Podman? Is there another platform I should consider running locally?

#containerization

That fancy new #glass style of #macOS #Tahoe 26 or the improvements to #Apple apps don't get me hyped, but the native #Linux #containerization surely does!

#container #OCI #macOS26

The #Apple #Containerization package v0.1.0 allows applications to use #Linux containers. Containerization is written in #Swift and uses Virtualization.framework on Apple silicon. #macOS 15 minimum (likely not supported for bug reports), macOS 26 beta recommended

https://github.com/apple/containerization

Apple introduced a Swift-powered, open-source alternative to Docker for running Linux containers on macOS, focused on security and isolation.
https://linuxiac.com/apple-launches-native-docker-alternative-for-macos/

#apple #macos #docker #containerization #opensource #linux

Here's how Apple's new Containerization framework works. It looks like an improvement over QEMU, Hypervisor.framework, and Virtualization.framework, which are used by Colima, Podman, et al.
https://github.com/apple/container/blob/main/docs/technical-overview.md

#macOS #docker #containerization #OCI