How screwed am I? And is there a simple way to resolve it?

redshark313 wrote:

Ah, ok. I just don't rememeber seeing this expanded view before and I thought either 14.4.1 had changed things or I'd somehow screwed up my HD format when erasing my USB stick.

If you look at the top of the Disk Utility, just to the left of the Disk Utility name, there is a View menu. It has three choices:

• Hide Sidebar
• Show Only Volumes
• Show All Devices

The screenshots that you and I posted are what you get when you have selected "Show All Devices". If you select "Show Only Volumes", Disk Utility hides the Media and Container lines and you get this:

Breaking this down:

• APPLE SSD AP1024Q Media represents the hardware device (SSD) that contains your data. On my Mac Studio, the AP---- name is different, but the idea is the same.
• Container disk3 is an APFS container that contains the volumes making up what the Finder calls "Macintosh HD"; the 'disk3' derives from it being /dev/disk3 in Terminal.
• Macintosh HD volumes is an APFS volume group that includes the volumes making up "Macintosh HD".
• Macintosh HD (directly below it) is a cryptographically-signed volume containing core OS files which the system normally only has to read. The idea is that the cryptographic signature makes it extremely hard for any malware to infect or vandalize the OS without the Mac detecting it.
• Macintosh HD snapshot is a further security measure. Apple doesn't just cryptographically sign the volume with the core OS files; they have the Mac run off an APFS startup snapshot of it as a further guard against tampering.
• Data is a volume where your data files go – where any operating system file that might have to be modified during normal operation goes – and perhaps, where stuff that could be hardened (but hasn't been yet) goes.

I believe that what you see as "Macintosh HD" in the Finder is actually a combination of "Data" and "Macintosh HD snapshot" … presented to you as a single logical drive.

I don't think that you are screwed – just confused by Apple's new "standard arrangement."

According to your tag line, your MacBook Air is running macOS 14.4 (Sonoma). The SSD is formatted using APFS, which is what I would expect for any internal Mac SSD these days.

In the old days – say on a machine running macOS 10.12 (Sierra), with a disk formatted using HFS+, you'd have a drive, and within that, partitions. Unless you had a Fusion Drive, you'd likely have a large Macintosh HD partition, and perhaps smaller EFI and Recovery partitions (that Disk Utility might or might not show you).

With APFS, there's the idea of a "container", where all of the "volumes" within a container share free space – but are separate from each other in other respects. With recent versions of macOS, Apple has hardened macOS, by putting some core operating system files into a cryptographically-sealed and normally read-only volume. Up at Finder level, it all looks like one "disk" (Macintosh HD) – but in Disk Utility, more of the true structure is revealed.

redshark313 wrote:

So I'm left now less worried, I mean, it seems I haven't changed the format of the MAcBook Air, correct?

I don't think you've changed it at all.

And of course, it seems to work fine (although, now maybe a bit slower in opening some apps - but maybe that's just me). So I can leave the HD as is? Is it correct?

"[Seems] a bit slower in opening some apps" is probably nerves speaking. You were worried by what you saw in Disk Utility, so you were inclined to see a problem that likely is not there. You can leave the internal SSD alone.

But I'm still confused as to why the USB sticks I formatted and I tried (exFAT, Apple J, etc.) all work ok with my MacBook Air but not with any other computer?!

What formats did you use with the USB drives? macOS and Windows can both read and write FAT32 and exFAT (although FAT32 does not allow files >4 GB, and some implementations don't support volumes >32 GB).

APFS and HFS+ would not be recognized by Windows PCs (unless you had installed special filesystem drivers), and APFS would not be recognized by older Macs (running versions of macOS prior to High Sierra).

There might also be something going on with the choice of partitioning scheme (MBR vs. GUID) – and I believe that some USB flash drives might even resist low-level reformatting.

Look familiar?

That's what the Ventura version of Disk Utility shows for my internal SSD. Nothing to worry about.