So with the announcement of Mac OS High Sierra and iOS 11 comes a big change under the hood
for all of our Apple devices.
It's called Apple File System or APFS for short.
So what is a File System?
Well a File System is how your computer stores files and other data on the hard drive or
other storage system.
Now all these details are things we don't have to worry about as users.
But it has to keep them organized.
It has to know where files are, where the data for the files is kept on the drive.
It has to move them around and take care of all sorts of things like creating new files,
deleting files, copying files, duplicating files.
All those details are part of the file system.
So before, and for many years, Apple had a file system called Mac OS Extended or HFS+.
This was the file system used on all Macs and was also used in iOS, on the Apple Watch,
and even Apple TV.
It worked great and it was generally pretty fast.
Now it's different than a system used say on a windows machine.
That's why a lot of times you had to format a drive with a windows format so it could
be read on windows and the Mac could also read that format.
But the native Mac format, Mac OS Extended, is the one that say your boot up drive would
use and your Time Machine drive would use.
Now we're going to change from using this Apple Mac OS Extended format to APFS.
So what makes APFS better.
Well there's several different things that it brings.
First and foremost is speed.
It's faster.
So it's a more modern system.
As you can imagine a system developed in 1998 isn't very good with handling things like
solid state drive, flash memory in phones, and things like that.
This is very optimized and should be faster for all things you need to do including even
booting up your device.
There's a special thing in APFS that allows you to clone files faster.
So say you have a huge video file and you want to make a copy of it.
You can duplicate it and it will happen instantly even though it's a huge file because it actually
just stores the data once and points to the same file for both copies.
As you make changes it records the differences between those files, not necessarily making
an entire other file and having everything copied there.
There's also something called Snapshots.
This should help a lot with backups.
Snapshots are a way for to quickly create read only copies basically saving the entire
state of the drive very fast.
Another thing that APFS handles very well is encryption.
So it's supported natively.
With the old operating file system you had to, you know, had to basically save an encrypted
file.
Which is just a normal file.
But this is handled much more directly in APFS.
There's also some crash protection.
It's going to write files in such a way that's going to avoid corruption.
So if you're writing a big file and say you loose power or something like that it's less
likely to cause a problem under APFS than it was under the old file system.
Space sharing is another advantage.
You'll be able to have a drive that's partitioned say into two or three different volumes.
They'll be able to share the same free space.
So you should be able to do some interesting things having a big drive partitioned and
not having to decide exactly how much goes with each partition right off the bat.
Where are we going to see the new APFS.
Well pretty much everywhere in the Apple world.
Because we're going to get it with the new version of Mac OS called High Sierra.
We're going to get it with iOS 11 and we're going to get it on the new versions of the
operating systems for both the Apple TV and the Apple Watch.
So they're going to switch the entire Apple world over to APFS.
How is this going to happen?
Well, it's going to happen automatically.
When you install High Sierra or iOS 11 part of the installation process will be converting
the drive in place to APFS.
It should just happen automatically and seamlessly.
Of course any time you do something as big as an upgrade to a new operating system you
should make sure your backup is all good and working first.
So there really is no danger in doing it this way.
And supposedly everything is going pretty smoothly with beta conversions.
How about backward compatibility?
So you're in the new version of the file system but now you have drives that are using the
old one.
Well, you'll still be able to read those old drives just fine.
But with the new drives how about if you have an old Mac, an old Mac that's running say
El Capitan.
Will it be able to read new drives formatted in APFS?
No it won't.
Now if they are Mac OS Sierra computers they will because Sierra supports APFS.
It just didn't implement it as the primary file system.
So anything you've got that runs Sierra will still be able to access new drives using APFS.
Any new computer you've got using APFS should still be able to access anything you have
formatted in an old format say on an old external drive with an archive.
So when is this going to happen?
Well, it will happen with the release of High Sierra and with iOS 11 which will happen in
the Fall.
In the past Apple has had the releases right around September 30th, October 1st.
We just don't know for sure when the date will be.
But when you upgrade to these operating systems that's when you'll be switched over to APFS.