DaisyDisk 4.26.1 offers a workaround for slow scanning on macOS Sonoma
A few users who have upgraded to macOS Sonoma have reported that scanning with DaisyDisk on macOS Sonoma began to freeze on a certain point for a significant time, resulting in a much onger overall scanning time.
Our investigation has shown that the slowdown on Sonoma happens in ~/ and ~/ folders and is caused by a new privacy feature introduced by macOS Sonoma.
Luckily, only a small number of Sonoma users will likely experience this slowdown. It only becomes noticeable when you have a lot of stuff in the mentioned folders, i.e. when you use specific apps that tend to spawn lots of files and folders in their data.
The Containers and Group Containers folders are the conventional place where user’s sandboxed applications store their data. Aiming to additionally protect user’s privacy, the operating system now performs additional checks when a third-party app tries to access these folders, in particular when DaisyDisk does its scanning to build the size report.
Unfortunately, it seems that Sonoma’s code for these access checks was written suboptimally, and can cause significant delays in client apps, even after the user has granted the access.
We have filed a bug report to Apple, and received an acknowledgment of the problem. Hopefully, Apple will address it in future versions of macOS.
In the meantime, this new version of DaisyDisk offers a temporary workaround, allowing you to still scan your disk with DaisyDisk at full speed.
In order to use this option, press the Option key on the keyboard while you are clicking the Scan button (or while selecting the Scan as Administrator menu command).
This will exclude the slow folders from scanning, allowing the scan to complete super fast, but this may also somewhat increase the hidden space, respectively.
This is a free update for the existing users of DaisyDisk 4.x.
Full change log is here.