Dive into APFS in Mints version 1.11

As I promised when I looked at how macOS Ventura and APFS mount an external SSD, here’s a new version of Mints that includes this as a standard Log Window. This brings the total number of tools provided by Mints to 22.


The new Disk Mount button will get you a log extract containing entries by most of the important actors in mounting an external disk. The predicate that it uses reads
subsystem CONTAINS[c] "com.apple.diskmanagement" OR subsystem CONTAINS[c] "com.apple.mobileaccessoryupdater" OR subsystem CONTAINS[c] "com.apple.DiskArbitration.diskarbitrationd" OR senderImagePath CONTAINS[c]
"IOAccessoryManager" OR senderImagePath CONTAINS[c] "apfs"

This is the first time that a predicate in Mints’ log windows has obtained log entries by the name of the sender, which is essential to get those from the two most important processes, IOAccessoryManager and APFS, which unfortunately aren’t given a convenient subsystem. IOAccessoryManager is the most important process involved in the early, hardware phase of disk mounting, and APFS is the key process for the later, software phase.


Controls in this new Log Window are the same as others. When looking at an event like a mount or unmount, time it to occur at a memorable time by the system clock. Leave your Mac until the actions are complete, give it another few seconds to be sure, then set the time and period to cover all expected log entries, and click on the Get log button.

You can then turn off MAU and DiskArb to see the main story given by IOAccessoryManager and APFS.

APFS + shows entries from IOAccessoryManager (IOAccMan) and APFS, which bear the brunt of the work. Because they’re seldom active at the same time, both processes are shown in the same category, using black lettering on white when in Light Mode. MAU is MobileAccessoryUpdater, whose messages are normally given as <private> unless you remove privacy from the log. DiskMan is DiskManagement, and DiskArb is DiskArbitration and diskarbitrationd, containing some important milestones.

I hope you’ll find this useful for investigating delays in mounting and unmounting. Because of its entries for APFS, it should also be useful for looking at any problem or event involving the file system, when using APFS.

Mints version 1.11 is now available from here: mints111
from Downloads above, from its Product Page, and via its auto-update mechanism.

I hope you find these insights both useful and fascinating.