According to the Wikipedia article about CoreStorage, it seems like the primary/only use case was Fusion drives (hybrid SSD/HDD hardware).
The article says “It renders your expensive storage hardware completely useless.” but I’m really curious what that hardware could actually be. This seems like a pretty dead technology.
Sidebar, but as an end user, I remain annoyed that there isn't seemingly something that's a worthy successor to fusion drives.
Like I have an Unraid box with dual NVMe (RAID1) as the "cache" drive and a bunch of spinning disks as the "array", but it's also very manual, like torrents get downloaded first to cache and then a nightly job syncs them to the array. Feels like a real missed opportunity to not be able to have this kind of config transparently managed.
The successor is SSDs, and I think for what Apple was using fusion drives for they are worthy successors.
The 2.5” form factor also took up a ton of space in a laptop form factor.
With my NAS box (TrueNAS ZFS) I don’t bother with a cache. I struggle to justify the cost/benefit ratio. The sustained write speed of a 3.5” disk isn’t so bad for the most common NAS use cases.
If I could go back to 2024 I think I’d use a m.2 2280 array for my NAS just because my present tense brain would think it was cheap. I don’t even hoard that much content so 4-8TB would be fine.
I've gotta agree. I'm not sure what expensive storage hardware would be both relevant today and unable to migrate off CoreStorage. For example, my most expensive storage is a NAS with an iSCSI target, and it couldn't care less what blocks I write to it. If I had a CoreStorage setup on it, I could migrate the data to a new target and then reuse that space for something else. The hardware wouldn't mind, or even know, that I'd changed what's on it.
You mentioned old, obsolete Fusion drives. I'm having a hard time thinking of anything else where that'd matter, so you're probably right about that. AFAIK you can reformat those to use something other than CoreStorage if you're actually stuck using those boat anchors.
I have one of those in an ageing late 2009 27" iMac running Linux. It is a Seagate ST2000DX001-1CM1, a 2TB "SSHD" which comes down to having 8 GB of NAND storage bolted on to a conventional 2TB drive. It doesn't need any special driver to do its thing so I wonder what that CoreStorage bit is supposed to be about.
Apple sold iMacs for many years that had a completely separate SSD and HDD, and CoreStorage was used to combine them into a single block device which was then partitioned and formatted as HFS+ or APFS.
Did you install that SSHD as an aftermarket upgrade? I thought the Fusion Drive configurations shipped by Apple used normal hard drives and separate SSDs and were purely software-managed (and also used much more than 8GB of flash).
CoreStorage was also used for HFS+ formatted and encrypted external storage like Time Machine backups. If you have any of those in your archive you might not be able to read them in the future.
It doesn't really do everything that a real LVM does though. This was used to support those annoyingly bad Fusion Drives. They dropped them around 2020 I think.
Apple software updates are always a downgrade. It's an opportunity to abuse customers that Apple just can't resist. If you're lucky all they do is break your muscle memory by moving buttons pointlessly.
Gave up on Apple after my MBP is effectively stuck in High Sierra and can't run anything modern, no thanks to the App Store removing older versions of software.
It's the iOSsification of macOS. Apparently, newer macBooks will now have touchscreen too ... once iPad OS and macOS are fully merged into OneMacOStoRuleThemAll, they'll finally lock down the bootloader on all Macs (why do you want to install anything else other an Apple OS?) and force all software install only through the App Store.
And even that was 13 or 14 years after Apple shipped their last computer with a Firewire port - long enough that those computers weren't even supported by macOS 26. Apple dropping support for a largely obsolete technology, which they hadn't used for well over a decade, should hardly come as a great shock.
Apple's Thunderbolt FireWire 800 adapter daisy-chained with their TB2-to-TB3 adapter should work on any modern system with Thunderbolt and FireWire support, as it just presents as a bog-standard PCI FireWire card.
So worst-case, you should be able to access your old drives on a modern Mac by booting from a FireWire-compatible OS (Asahi or older macOS) on an external drive.
The author has another recent post from Oct 30 wherein DNS stops working on their machine every week or two. Unsetting/resetting the servers fixes it. I can't imagine daily driving a workstation with flaky DNS.
I guess I misjudged Apple's commitment to support HFS+ long-term.
It now seems like there's no real native way of doing encrypted backups to HDDs on macOS (APFS not really recommended for HDDs)... the options are either encrypted Time Machine to a network location, or a third-party tool.
I don't think APFS was designed or tuned with HDDs in mind, but it will work just fine. Especially for backups where random read/write performance is not important.
I would not recommend using an APFS formatted HDD for Time Machine. It's painfully slow. With my Samsung T7 the hourly Time Machine backups are usually finished after a couple of minutes. Using my older HDD they can easily take 20 minutes to half an hour.
It's definitely APFS. I've had the pleasure* of HFS+ and APFS on the same external HDD and APFS is horrible. Given it is optimised for solid-state drives[0], it's understandable there'd be some slack but it is absolute horse paste.
(If I could create an encrypted external HFS+ volume, I would but macOS hasn't allowed that for a while as far as my experience goes - it's non-encrypted HFS+ or encrypted APFS.)
While time machine used to be snappy on HDD it was build out of one of the weirdest little hacks hard links in folders. The new Time Machine might front a similar front end but under the hood its a different beast. You're having to mount snapshots as you move through time.
MacOS is only Posix like, and does a lot of weird nonstandard things in the background regarding mounting drives/images.
There are restrictions on where things can run, what can run, and what is accessible to the process.
SSHFS is slow, but at least can mount windows/linux/android systems over VPN without issues. Look at what is needed to bring up SSHFS or NTFS support, and you should have a better idea of Apples walled garden policies.
Apple makes information appliances, and not general-purpose computers. Some may disagree, but they usually choose an exception use-case rather than the normal experience of users. =3
That would happen around once a year when I used the 2013 AirPort Time Capsule.
It seemed to stop killing itself when I moved to a ZFS backed samba share.
Funnily enough I also kept snapshots enabled because I was expecting TM to bork itself eventually, so I could always rollback to a working state but I don’t remember needing to use that.
I also had a recurring corruption issue using a Windows Server file share.
Before MacOS 27, I was always able to remove the Time Machine destination, replace the corrupted sparse bundle with a fresh empty one, and reconfigure that as the new TM destination. I even made a script for this, so I didn’t have to figure out the terminal commands every time.
Unfortunately the script doesn’t work anymore; it throws ‘error 25’ on my MacOS 27.
What’s weirdest is that, before the corruption, TM backup and restore used to work fine on my MacOS 27. Seemingly the backup functionality works as normal, but setting the TM destination was broken.
I backup to TrueNAS which configures Samba/ZFS to take a snapshot before each backup. If TM decides to corrupt a backup, I can revert to a snapshot. I've only ever had to do this once in years of operation with several Macs backing up (each to their own share).
Ok I may be an idiot, but I just have a permanently attached external disk that does Time Machine, what am I missing out on? Why network location? Or are you backing up massive amounts of data? (for me it’s just 2TB)
It's mainly for multiple people in a household to back up to one location, especially if some have laptops that are often not on desks. Those Airport APs used to also let you attach disks for this. You could even do it over a VPN.
> I guess I misjudged Apple's commitment to support HFS+ long-term.
One thing I have learned with (current) Apple is to never trust their commitment to support something they're not using. And even be wary for stuff they are using. (in my mind, a core technical difference between Microsoft & Apple is that MS will bend over backwards for backwards compatibility, whereas Apple will drop it as soon as they can, and sometimes sooner still)
They replaced their use of HFS+ with APFS in 2017, so it's had a good run.
I have heard from ex-CoreOS (the Apple org) colleagues is that the organization is run intentionally lean, because the leadership believes that people do their best work under pressure. This leads, among other things, to aggressive YAGNI pruning.
With macOS 27, I don't know who Apple is trying to outdo?. 27 has been a total disaster for me and my setup at home.
Back when there was a little more rivalry between Microsoft and Apple, Apple would come up with these really cool things to showcase the operating system and make lives easier. Now, I don't know what it is they're trying to prove with this operating system. I also hate the fact that they skinned the whole operating system around a failed hardware product.
I can't immediately find prior warnings that this was coming.
The following technical note from July 22nd says Encrypted HFS+ Volumes won't be supported in macOS *28*, so this seems a bit early...
https://support.apple.com/en-us/125615
throwaway27448 | 7 hours ago
duskwuff | 7 hours ago
Because it isn't LVM, and giving it the same name as another similar-but-distinct technology would just make matters more confusing.
Grombobulous | 7 hours ago
The article says “It renders your expensive storage hardware completely useless.” but I’m really curious what that hardware could actually be. This seems like a pretty dead technology.
mikepurvis | 7 hours ago
Like I have an Unraid box with dual NVMe (RAID1) as the "cache" drive and a bunch of spinning disks as the "array", but it's also very manual, like torrents get downloaded first to cache and then a nightly job syncs them to the array. Feels like a real missed opportunity to not be able to have this kind of config transparently managed.
jmgao | 6 hours ago
Grombobulous | 6 hours ago
The 2.5” form factor also took up a ton of space in a laptop form factor.
With my NAS box (TrueNAS ZFS) I don’t bother with a cache. I struggle to justify the cost/benefit ratio. The sustained write speed of a 3.5” disk isn’t so bad for the most common NAS use cases.
If I could go back to 2024 I think I’d use a m.2 2280 array for my NAS just because my present tense brain would think it was cheap. I don’t even hoard that much content so 4-8TB would be fine.
Maybe one of these nifty things would be fun: https://www.bee-link.com/products/beelink-me-mini-n150
hypercube33 | 4 hours ago
kstrauser | 7 hours ago
You mentioned old, obsolete Fusion drives. I'm having a hard time thinking of anything else where that'd matter, so you're probably right about that. AFAIK you can reformat those to use something other than CoreStorage if you're actually stuck using those boat anchors.
hagbard_c | 6 hours ago
mrpippy | 6 hours ago
wtallis | 6 hours ago
MilaM | 6 hours ago
sysguest | 7 hours ago
zamadatix | 7 hours ago
throwaway27448 | 7 hours ago
wolvoleo | an hour ago
vondur | 7 hours ago
throwaway27448 | 7 hours ago
It manages logical volumes. Any quibbling is a matter of degree.
exabrial | 7 hours ago
drooopy | 7 hours ago
otterley | 7 hours ago
sys_64738 | 7 hours ago
varispeed | 7 hours ago
R1D3R | 6 hours ago
thewileyone | 3 hours ago
thisislife2 | 6 hours ago
icedchai | 5 hours ago
hmartin | 7 hours ago
traceroute66 | 7 hours ago
Erm... it was dropped in macOS 26 back in 2025 ?
https://www.techspot.com/news/108394-usb-killer-dead-apple-d...
duskwuff | 6 hours ago
RulerOf | 5 hours ago
Only really used it as a scratch drive for junk but it was still handy.
jasomill | 4 hours ago
So worst-case, you should be able to access your old drives on a modern Mac by booting from a FireWire-compatible OS (Asahi or older macOS) on an external drive.
conradev | 3 hours ago
Thunderbolt 3 to Thunderbolt 2 Thunderbolt 2 to FireWire 800 FireWire 800 to FireWire 400
to plug a modern Mac into an iMac G4 in Target Disk Mode
Now you need to add another layer: virtualizing old macOS on a modern Mac
mahboi | 3 hours ago
hmartin | an hour ago
As in, not even a dialog saying "hey this drive isn't support anymore"... just... nothing.
What exactly is Apple gaining by dropping a (presumably) super stable driver??
Nice that you can dismiss this as "largely obsolete technology" tho.
conradfr | 4 hours ago
hmartin | 2 hours ago
flanz_10 | 7 hours ago
reaperducer | 5 hours ago
Well, I guess I can finally throw out all those FireWire cables I have "just in case."
Fortunately, my FireWire drives also support other interfaces, though far more slowly.
varispeed | 7 hours ago
accrual | 5 hours ago
https://wadetregaskis.com/dns-resolution-failures-in-macos-2...
soulofmischief | 3 hours ago
Marsymars | 6 hours ago
I posted ~7 months ago about my decision to use HFS+ for backups, and had a couple skeptical replies. (https://news.ycombinator.com/item?id=47317123)
I guess I misjudged Apple's commitment to support HFS+ long-term.
It now seems like there's no real native way of doing encrypted backups to HDDs on macOS (APFS not really recommended for HDDs)... the options are either encrypted Time Machine to a network location, or a third-party tool.
Guess I'll figure out SuperDuper or Carbon Copy.
mrpippy | 6 hours ago
MilaM | 6 hours ago
fl0id | 6 hours ago
zimpenfish | 4 hours ago
(If I could create an encrypted external HFS+ volume, I would but macOS hasn't allowed that for a while as far as my experience goes - it's non-encrypted HFS+ or encrypted APFS.)
[0] https://support.apple.com/en-gb/guide/security/seca6147599e/...
outofpaper | 6 hours ago
isityettime | 6 hours ago
https://www.openzfsonosx.org/
Joel_Mckay | 3 hours ago
There are restrictions on where things can run, what can run, and what is accessible to the process.
SSHFS is slow, but at least can mount windows/linux/android systems over VPN without issues. Look at what is needed to bring up SSHFS or NTFS support, and you should have a better idea of Apples walled garden policies.
Apple makes information appliances, and not general-purpose computers. Some may disagree, but they usually choose an exception use-case rather than the normal experience of users. =3
https://rclone.org/install/
Marsymars | 15 minutes ago
lakeviewterrace | 5 hours ago
this has a bonus feature where it will slowly corrupt itself over time and offer to start a completely new backup instead.
thfuran | 4 hours ago
yangm97 | 3 hours ago
It seemed to stop killing itself when I moved to a ZFS backed samba share.
Funnily enough I also kept snapshots enabled because I was expecting TM to bork itself eventually, so I could always rollback to a working state but I don’t remember needing to use that.
nijave | 2 hours ago
The only thing that definitely made it worse was smb over openvpn. It'd corrupt itself every couple months instead of once or twice a year.
themanualstates | 2 hours ago
Before MacOS 27, I was always able to remove the Time Machine destination, replace the corrupted sparse bundle with a fresh empty one, and reconfigure that as the new TM destination. I even made a script for this, so I didn’t have to figure out the terminal commands every time.
Unfortunately the script doesn’t work anymore; it throws ‘error 25’ on my MacOS 27.
What’s weirdest is that, before the corruption, TM backup and restore used to work fine on my MacOS 27. Seemingly the backup functionality works as normal, but setting the TM destination was broken.
js2 | 2 hours ago
mistrial9 | 2 hours ago
stingraycharles | 5 hours ago
Marsymars | 4 hours ago
root9876 | 4 hours ago
mahboi | 3 hours ago
stingraycharles | 2 hours ago
mahboi | 2 hours ago
AceJohnny2 | 4 hours ago
One thing I have learned with (current) Apple is to never trust their commitment to support something they're not using. And even be wary for stuff they are using. (in my mind, a core technical difference between Microsoft & Apple is that MS will bend over backwards for backwards compatibility, whereas Apple will drop it as soon as they can, and sometimes sooner still)
They replaced their use of HFS+ with APFS in 2017, so it's had a good run.
AceJohnny2 | 4 hours ago
unsloppable | 3 hours ago
qmr | 3 hours ago
mahboi | 3 hours ago
hoherd | 3 hours ago
whatever1 | 6 hours ago
For backups use a NAS. You can find from completely plug and play options to bring your own machine ones.
mahboi | 3 hours ago
someonehere | 5 hours ago
Back when there was a little more rivalry between Microsoft and Apple, Apple would come up with these really cool things to showcase the operating system and make lives easier. Now, I don't know what it is they're trying to prove with this operating system. I also hate the fact that they skinned the whole operating system around a failed hardware product.
AceJohnny2 | 5 hours ago
https://developer.apple.com/documentation/macos-release-note... (Search for CoreStorage; their fragment links are hilariously broken)
The premier 3rd Party technical blog Eclectic Light talked about it in June: https://eclecticlight.co/2026/06/17/what-to-do-with-your-enc...
I can't immediately find prior warnings that this was coming.
The following technical note from July 22nd says Encrypted HFS+ Volumes won't be supported in macOS *28*, so this seems a bit early... https://support.apple.com/en-us/125615