When you upgrade any Mac with an Apple
Fusion Drive to Mojave or Catalina, that drive
is automatically converted to Apple’s new
APFS file system. You don’t have any choice,
and both versions of macOS require to be
started up from APFS rather than the old Mac
Extended or HFS+ format.
Although APFS isn’t ideal on a hard disk,
where most users notice reduced performance,
it does works well on Fusion Drives and SSDs.
macOS then uses the SSD component within a
Fusion Drive to cache active files and improve
main storage performance on the hard disk.
The only potential issue arises with Fusion
Drives with SSDs smaller than 100GB, wherehigh levels of disk activity could in some cases
wear out the SSD and cause early failure, but
so far this appears rare.
In contrast, Time Machine backups are still
required to be on disks which are formatted
using HFS+. So your current backup disk
won’t have its format changed. However,
Catalina in particular makes changes to the
structure of existing backups which prevent
you from accessing them using older versions
of macOS and Time Machine. Your first full
backup after upgrading can also take many
hours or days. Consider archiving those old
backups and starting a fresh set for Catalina,
which can save time and trouble.> Which disks get converted by Catalina?
Would my iMac with an internal Fusion Drive upgrade fully to Catalina? And what would
happen with the Time Machine backups on its external hard disk? Would those be
converted to Apple’s new file system?Image rights: Apple.Although Catalina must start up from a disk in
the new APFS format, it can only make Time
Machine backups to those in older HFS+.IS THERE A SAFE WAY TO
DISABLE SIP?
No: System Integrity
Protection is a primary
defence mechanism which
protects system files in
macOS. There are few
circumstances when you
should ever consider turning
it off. Make a note to yourself
that SIP is turned off until
it’s safely turned back on.
Don’t forget, or your Mac
could get something nasty.HOW TO CHANGE THE
PRIMARY CONTACT
FOR AUTOFILL?
Open Contacts, select the
card you want to set as “My
Card,” then in the Card
menu, use the “Make This
My Card” command. It’s
worth checking this in
Contacts, and by opening
Safari’s Preferences, clicking
on the AutoFill tool, then on
the top Edit... button.68 SEP 2020 maclife.com
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