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.
This has been detailed as a major improvement in lightweight virtualisation, where it promises to overcome the most significant performance limitation of VMs running on Apple silicon Macs. However, ASIF disk images are available for general use, and even work in macOS Sequoia. This article shows what they can do.
↫ Howard Oakley
Exactly what it says on the tin.
Giampalo should just step up and say NO! No more garbage FS, if they can change processor type three times, HFS can be retired.
Just make a BFS like filesystem with working metadata, and yeah the openBFS is open source and BSD licensed to use.
HFS in all its iterations needs to be deprecated.
NaGERST,
For the last ~7 years APFS has replaced HFS+ (which was the successor to HFS). I’m not sure the original HFS is even supported by macs at this point.
(And yes, it uses B-trees and has metadata checksumming)
What has to do the FS with the topic?
They are talking about about disk images. (like .vhdx / .vmdk /.vdi on real computers)
@the solutor
It is tradition in this site for some posters to insert BeOS/Amiga/OldWindows/etc, no matter how unrelated the topic, for some weird reason.
APFS (the standard macOS filesystem at this point) is a bree-based Copy-on-Write filesystem much like ZFS, Btrfs, or BCachefs..
I have no idea about Apple or MacOS — but can someone explain WHY they needed to implement “another one” instead of using an established FS here?
Not an authority but these are my thoughts:
1) Branding – it is easier to brand something as superior and a differentiated benefit if it is unique. As such, Apple has a fairly strong not-invented-here culture.
2) Lock-in – a core part of the Apple strategy is the walled garden
3) Control – Apple values their strategic independence – they want to be able to change hardware – they want to be able to transition everybody to new software – they cannot do this unless they control the platform – both to be able to take it where they want and to take it away from people that do not want to follow
4) Licensing – this is a combination of the above – they need proprietary or permissive licensing – copyleft licenses are all about transferring control away from the developer – you cannot differentiate and parade the exclusivity of features that others can legally copy
It’s a format that will be use pervasively by their VM/Containers/App Store stuff. So Apple wants to have as much control over it as possible, or at the very least not be at the mercy of 3rd parties.
It really is not that big of a deal. Disk Images have been traditionally a thing in Mac-land, this is just an updated version that they really needed to address.