My Time Machine backups (from MacOS Sonoma, installed on a14" M3 MacBook Pro running the most recent Sonoma OS (I’ve not updated previously because of nostalgia: before the 2017 wildfire, I’d been a Sonoma County resident for almost 2 decades, afterwards technically “homeless” (although we did still own a rubble-filled hole in the ground). My backup strategy included two arms: SuperDuper Clones to an external OWC TB3 SSD, and incremental Time Machine backups to a 4 TB G-Drive rotating platter mechanism formatted HFS+.
Recently, my TM backups (even incremental) have taken forever (longer than an hour, with the backup interval set to BE the default 1 hour)… Several people I trust have suggested I should be backing up to an APFS-formatted device, even if it was a rotating platter external drive. So, I used Disk Utility to reformat a spare 1 TB drive just to test, and I was somewhat surprised to see how Disk Utility logged that activity:
Erasing “G-DRIVE mobile USB-C Media” (disk4) and creating “MB Pro Time Machine Test”
Unmounting disk
Creating the partition map
Waiting for partitions to activate
Formatting disk4s2 as Mac OS Extended (Journaled) with name MB Pro Time Machine Test
Initialized /dev/rdisk4s2 as a 931 GB case-insensitive HFS Plus volume with a 81920k journal
Mounting disk
Creating a new empty APFS Container
Unmounting Volumes
Switching disk4s2 to APFS
Creating APFS Container
Created new APFS Container disk5
Preparing to add APFS Volume to APFS Container disk5
Creating APFS Volume
Created new APFS Volume disk5s1
Mounting APFS Volume
Setting volume permissions
Operation successful.
Is it the case that erasing and reformatting a previously used rotating platter drive always results in Disk Utility doing an INITIAL format in HFS+, and only AFTER that, substituting the APFS formatting? (Way above my pay grade in understanding, but still curious).
Jim Robertson