126 MACWORLD APRIL 2020
HELPDESK MAC 911works the same way
in earlier versions,
too:
- Launch
Messages. - Click the
conversation that
contains the items
you want to delete. - Click Details in
the upper-right
corner. - In the pop-
down window that
appears, you can select between Photos
and Files. - Control-click on a single image or a
selection of images (you can use Shift-click
and Command-click to add to the
selection), choose Delete from the pop-up
menu, and the confirm the deletion.
WHY YOU’RE PROMPTED TO
ERASE AN EXTERNAL DRIVE
WHEN YOU USE IT WITH TIME
MACHINE
When you attach an external drive to a
Mac to use with Time Machine and confirm
the prompt that appears asking if you want
to use it for that purpose, you may then be
prompted to erase the drive. Why does
that happen?
As noted in previous columns, Apple
supports backing up macOS drives in both
the older HFS+ (“Mac OS Extended
(Journaled)” in Disk Utility) and newer
APFS formats. But Time Machine backup
drives must use HFS+ for now. It’s a weird
requirement on Apple’s part after
automatically migrating all Macs startup
volumes to APFS during recent macOS
version updates (10.13 migrated SSDs; 10.14
migrated hard drives and Fusion drives).
When you see a prompt that asks you
to erase the drive, that’s because it’s not
formatted with HFS+. It might be perfectly
Finder mountable, because it uses APFS,
FAT32, or ExFAT. However, Time Machine
can’t work with it, and thus macOS gives
you an option to erase.
If you are willing to switch the drive
over, make sure you have all the data on it
copied somewhere else. After erasing and
reformatting as HFS+, you can store other