Tuesday, August 29, 2017

APFS to be Mandatory for SSDs in High Sierra

Apple (via Felix Schwarz):

When you upgrade to macOS High Sierra, systems with all flash storage configurations are converted automatically. Systems with hard disk drives (HDD) and Fusion drives won’t be converted to APFS. You can’t opt-out of the transition to APFS.


Boot Camp doesn’t support Read/Write to APFS-formatted Mac volumes.


Volumes formatted with APFS can’t offer share points over the network using AFP.

I assumed Apple would let you opt-out, since that was possible for the betas.

Previously: Pondering the Conversion From HFS+ to APFS.

Update (2017-08-29): Steve Moser:

I wonder what this means for hackintoshes since I read some where that APFS requires Apple firmware.

Update (2017-08-31): Edward Marczak:

For anyone worried about being “forced” into converting to APFS, startosinstall still supports the --converttoapfs flag

20 Comments RSS · Twitter

The “APFS Compatibility” section makes statements like “Devices formatted as HFS+ can be read and written to by devices formatted as APFS.” What is a “device” in the context of such a sentence? Disks do not write to each other; an operating system does. I don't understand what this is supposed to mean.

Why is AFP (Apple's own venerable network filing protocol) not supported, whereas SMB (the Microsoft one) is? Weird.

Fusion drives aren't supported by APFS? I thought I'd read otherwise. Maybe plans changed.

I presume the 'Devices formatted as HFS+" statement is referring to external HDDs.

Ben: AFP is likely not supported because it hasn't been significantly overhauled recently (although it got some extensions to support Time Machine), and could even have impacted the design of APFS had supporting it been a requirement. For example, APFS has 64-bit file IDs, and I highly doubt AFP supports it as-is. SMB has been majorly overhauled recently (SMB 2 and newer are vastly different than SMB 1.x), and supports among other things persistent handles to files, which are valid across disconnections, as well as locking.

Anonymous: Fusion drives are supported, they just won't be automatically converted during installation.

AFP is deprecated, macOS defaults to SMB wherever possible instead. There's even support for Time Machine over SMB now.

The issue with Hacintoshes, as well as Parallels/Fusion is that the *boot loader* (EFI) must understand the filesystem to be able to boot from it. That's why High Sierra update updates EFI too. This will presumably be solved by an update to one of the open EFI implementations soon enough.

Grab the popcorn. This is going to be quite a show.

I wonder why the automatic conversion is limited to SSDs, given that AFPS also supports HDDs and Fusion Drives. My best guess is performance: an HDD with lots of data could take unacceptably long (hours?) to convert, and Apple doesn't want the update to take that long.

It appears that the automatic conversion to APFS of your boot volume only occurs if it's the only volume (partition) on the disk. As soon as you have more partitions on it, the conversion does not occur in my test cases.

Also, not all kinds of APFS formatted disks will be readable on 10.12.6. I have an example of a dir with hard links inside which appears blank on 10.12.6.

Thomas: APFS does not support directory hard links.

@ Brendan: there's also the fact that OS X 10.11 and macOS 10.12 are disasters, from a performance point of view, on Mac systems with a HDD startup disk. So the conversion could be super slow and the performance gain would not be there after all.

Bryan Pietrzak

I manage 19,000 Macs for a school district and we did some testing of 10.9, 10.10, 10.11 and 10.12 on some of our older iMacs (2009 to 2011 models mostly)

10.12 on the same hardware was the clear winner in overall performance. It felt noticeably better and many tasks were quicker.

Note that our results could be skewed by the fact that we have mandatory AV installed and 10.12 has the newest version of that AV package - older OSes can't run the latest version so there could be optimizations there that allow 10.12 to outperform 10.9 for us.

But in our case, we couldn't be happier with 10.12. It pretty much every respect it's been an improvement for us.

@Bryan: Interesting. I don't have access to that huge amount of Macs. On the Mac Pro model that can run 10.11 but not 10.12: 10.11 is way slower than 10.7 or 10.8. On an iMac 27" that can run any recent OS, upgrading to 10.12 made the iMac unusable (permanent disk access - this could be relatif to iCloud drive backup though) and on 2 less recent iMac, same problem with 10.11 or 10.12: slowness due to permanent disk activity. In all cases.

@Bryan @someone I saw an old (non-SSD) MacBook become almost unusable following an OS upgrade. It went from being kind of slow but usable to frequently (temporarily) locking up. It seemed to be due to lots of processes accessing the disk at once, even just sitting in the Finder after booting. But this was definitely one of the releases before 10.11.

@Bryan @someone @michael yes, same here. MBP 2011 with spinning disk got very slow, with frequent spinning beach balls, maybe around 10.10. I finally got around to try booting from an external SSD (in an enclosure, and coming from an upgraded MBP on which I changed the SSD), and it's usable again. Huge difference, it does not lock up anymore. Now, I just have to buy an internal SSD because it's inconvenient to have that external SSD always attached to the laptop (unfortunately, I can't just use the same SSD I swapped from the other MBP).

Bryan Pietrzak

After imaging our computers tend to be very sluggish for an hour or so - between spotlight indexing, our inventory control system taking inventory, AV scans and update scans (the first three all require significant scanning of the drive) it's just very slow. But once all that settles down 10.12 even on a 2011 iMac runs pretty well.

We don't use any cloud services - so I can't speak to the impact or not of iCloud Drive and we (sadly) have very few Macs with SSDs. Note that we probably have 1200 or so MacBook Pro 2012 models with HDD and those run 10.12 quite nicely for our staff.

@Bryan The Mac I’m thinking of remained slow for years after the update and does not use cloud services, either. I have no way of ruling out whether it was a hardware issue, but the timing seemed to point to software.

Current macOS does not perform adequately with a hard drive (probably that goes back to 10.8 or 10.9, though I've been SSD-only since). Try using a brand new HDD (not Fusion Drive) iMac in an Apple Store - it's just embarrassing for a computer of that price to perform so badly. Modern Windows is much better on a hard drive.

My guess is that there's a significant performance regression on HDDs but not SSDs with APFS in 10.13, which is why they're not upgraded automatically.

In my very subjective experience, 10.9 and 10.12 seem to be the high points of subjective system performance among their neighbors. Even if you have a SSD if you plan on keeping your Mac for a few years (and you can replace it!) I'd recommend upgrading. I recently replaced my 2012 Mac mini's bundled internal SSD with a Samsung 850 EVO, certainly not the fastest thing around, and noted a pretty significant improvement.

One thing that has just *exploded* over the past few years is the number of background processes macOS runs by default - likely as a result of wanting to separate things for security. This places a lot more random I/O demands on the OS.

In response to @ Jesper - I never said "directory hard links". I talked about regular file hard links.

[…] also: comments about Mac performance changing with OS […]

Michael Domino

Hi, I was wondering if anyone has had problems updating from Sierra to Mojave? On a restart after the install, the Mac can’t boot and presents the black circle-with-a-slash screen, an indication that the computer couldn’t find a bootable volume. Or, the install screen will say "Install resources cannot be found." The problem seems to be related to some third-party software that might be installed, but I don't know the exact mechanism of the problem. Does anyone have any insight into this? Thanks!

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