Catalina on HFS+ - a HOWTO

[toru173]

I've just had some success getting Catalina on HFS+:

Please ignore that I selected the APFS volume of my main boot drive on the tester Mac. I hadn't noticed when taking the screenshot and when I did notice I'd already erased the volume for my next test.

Method:

From an image of a working install of macOS Catalina (/Volumes/Macintosh\ SD/):

ditto /Volumes/Macintosh\ SD/ /Volumes/Macintosh\ HFS+
ditto /Volumes/Macintosh\ SD\ -\ Data/Users /Volumes/Macintosh\ HFS+
ditto /Volumes/Macintosh\ SD\ -\ Data/Device/ /Volumes/Macintosh\ HFS+

Ditto merges directories and keeps permission. Verbose mode boot spews out a lot of errors, and I saw high CPU usage once logged in. It eventually quietened down, though.

I'm trying again from a fresh, unbooted install made to a disk image, then I will try directly from a macOS installer. Wish me luck!

 

[jackluke]

I attempted to manually clone an APFS Catalina Installation to an HFS+ volume, considering the old structure/layout before Catalina, I guess HFS+ is unaware how to handle "Users and Library" on a separated partition, unless adding some symlinks, so I filled from APFS Data into the HFS+ the /Device/ Content copying it in the root HFS+ , and moved the /System/Applications/ into HFS+ /Applications/ only result I have a working Catalina HFS+ single user mode, but typing "exit" it stuck during verbose mode lines or a kernel panic before reaching the loginUI.

While as you know, restoring a Catalina BaseSystem.dmg (it's still in HFS) does work as a kind of "HFS Recovery HD".

 

[toru173]

I had the same behaviour when just copying the contents of /System/Library/Templates/Data to /. I’m still looking in to it, but I believe macOS stores a heap of temp and config files there that are set up by the installer. I need to dump the install log and read what it’s doing.

The existence of /etc/rc.cdrom is what tells launchd it’s launching the recovery environment. It would be interesting to see what happens if you restore basesystem.dmg and delete it and /etc/rc.install

 

[jackluke]

It's all about this new Data Volume, since on Mojave (and HighSierra) almost automatically "Preboot+VM+System" were combined in one only HFS+ Volume, but they added also some new security frameworks, for example also broken Catalina HFS+ single user mode I am unable to use "kextcache".

 

[toru173]

It's all about this new Data Volume, since on Mojave almost automatically "Preboot+VM+System" were combined in one only HFS+ Volume, but they added also some new security frameworks, for example also broken Catalina HFS+ single user mode I am unable to use "kextcache".

Ah! I think you may not have copied everything. Kextcache lives at /sbin (I think), and it is at /Data/Device on Catalina

 

[jackluke]

I meant kextcache throws the same error of Catalina APFS single user mode, it can't be executed due to a security framework, that I don't know where is, same for "fsck -fy or fsck_apfs -y" it ask for a /dev/diskX/ to be mounted in read-only, tried to mount as -rdonly, but didn't worked.

 

[toru173]

I meant kextcache throws the same error of Catalina APFS single user mode, it can't be executed due to a security framework, that I don't know where is, same for "fsck -fy or fsck_apfs -y" it ask for a /dev/diskX/ to be mounted in read-only, tried to mount as -rdonly, but didn't worked.

I haven’t seen that error. Interesting

 

[toru173]

Installing to the volume using the 10.13 installer and then copying /System/Library/Templates/Data/Device and /System/Library/Templates/Data/Users to / did not result in a bootable system. Rebuilding the dyld and kextcache (which the installer does after the fact) doesn't result in a bootable system. So far, the easiest way to install to HFS+ appears to be to install to a sparseimage on the target volume, then dittoing the files to the root of the target. Investigations are ongoing.

 

[toru173]

The same process works to install to an HFS formatted RAID; however, once installed you need to rebuild the booting partitions using kextcache -fu /Volumes/Macintosh\ RAID. This only seemed to work correctly when running kextcache from the installer

 

[toru173]

Some pictures. Performance is terrible, but I don't know how much of that is Catalina on HFS+ and how much is my rubbish USB sticks

 

[jackluke]

Some pictures. Performance is terrible, but I don't know how much of that is Catalina on HFS+ and how much is my rubbish USB sticks

In this configuration showed you are using Catalina in APFS since your main disk1 label "Macintosh HD" is contained into a disk container, and the disks containers in macOS are only APFS.

So for sure this is not a Catalina HFS+ installation.

I am more convinced that a Catalina HFS+ install is no more possible, unless you can replicate your first attempt without using RAID and using "ditto".

 

[chrfr]

In this configuration showed you are using Catalina in APFS since your main disk1 label "Macintosh HD" is contained into a disk container, and the disks containers in macOS are only APFS.

So for sure this is not a Catalina HFS+ installation.

I am more convinced that a Catalina HFS+ install is no more possible, unless you can replicate your first attempt without using RAID and using "ditto".

You're misreading the information. You can see that the RAID is mounted at /, which indicates that it is the root volume and thus it's where the OS is running.
As for why one would want to force Catalina to run in this configuration, I have no understanding of that.

 

[toru173]

As for why one would want to force Catalina to run in this configuration, I have no understanding of that.

Because I can, and I need a bootable HFS+ install for some internal tools. I'm glad to see I'm amusing the community!

 

[jackluke]

You're misreading the information. You can see that the RAID is mounted at /, which indicates that it is the root volume and thus it's where the OS is running.
As for why one would want to force Catalina to run in this configuration, I have no understanding of that.

I guess no, in the configuration showed the OS is "contained" into a main "/" RAID HFS+ disk but is running from an APFS container namely disk1

Wait!

My mistake! I have misread the labels for Startup disk "Macintosh HD" and "Macintosh RAID"

so maybe it's a native Catalina HFS+ booting.

 

[toru173]

I guess no, in the configuration showed the OS is "contained" into a main "/" RAID HFS+ disk but is running from an APFS container namely disk1

Wait!

I have misread the "Macintosh HD" and "Macintosh RAID"

so maybe it's a native Catalina HFS+ booting.

Some background:

My main machine is running 10.13.3 (because I haven't updated in so long) installed to a single APFS container. I am installing Catalina to 4x USB sticks in RAID with HFS+, with a similar setup to what I did in https://forums.macrumors.com/threads/mojave-on-raid-with-apfs-a-howto.2125096/

 

[jackluke]

Some background:

My main machine is running 10.13.3 (because I haven't updated in so long). I am installing to 4x USB sticks, like I did in https://forums.macrumors.com/threads/mojave-on-raid-with-apfs-a-howto.2125096/

You're right, my mistake, I have misread the labels, however what do you have in disk1 ? Another Catalina APFS from where you "ditto-ed" ?

Or Mojave or HighSierra in APFS maybe ?

Just a curiosity.

 

[toru173]

You're right, my mistake, I have misread however what do you have in disk1 ? Another Catalina APFS from where you "ditto-ed" ?

/dev/disk1 is my APFS container for my 10.13 internal drive. I unmounted and deleted the sparse image when I successfully booted the RAID array

 

[jackluke]

/dev/disk1 is my APFS container for my 10.13 internal drive. I unmounted and deleted the sparse image when I successfully booted the RAID array

Maybe RAID is not yet properly supported on Catalina beta 1, I mean your first configuration with a standard (non-RAID) HFS+ disk ran better with Catalina ? I guess

Ah you installed Catalina on USB sticks that's why performs so slowly.

I usually as external tests use a SATA SSD USB.

 

[pippox0]

Hi,
i'm trying to get a working HFs+ partition with Catalina.
I 'm getting some experiments with Virtual installation.
I'm using Parallels Desktop for mac because i can copy, clone, modify VM without rebooting physical device.

What i have just done.
1. i have installed Mojave in Parallels desktop and then i have upgrade to macOs 10.15 beta.
the VM is APFS and after upgrade i have macOS and macOs-Data partitions (15Gb) .
2. I have created a second virtual Disk and i have cloned with Caron Copy Cloner Catalina to the another VM HFS+ (10Gb) - With CCC data partition is not copied.

3. With Finder i have copied data from Data-partition to HFS+
I'm trying to recreate folders like "Mojave"
i have copied Applications from Data to Applications in / HFS+
i have copied System/Library -> HFS+
I have copied Library , Vm , etc.

It's a Proof of Concept ...

For now HFs+ is still not working , but i feel i get close to success ....

I belive that if i'm able to recreate an old style scheme of folders, it will be able to boot from HFS+

 

[toru173]

Hi,
i'm trying to get a working HFs+ partition with Catalina.
I 'm getting some experiments with Virtual installation.
I'm using Parallels Desktop for mac because i can copy, clone, modify VM without rebooting physical device.

What i have just done.
1. i have installed Mojave in Parallels desktop and then i have upgrade to macOs 10.15 beta.
the VM is APFS and after upgrade i have macOS and macOs-Data partitions (15Gb) .
2. I have created a second virtual Disk and i have cloned with Caron Copy Cloner Catalina to the another VM HFS+ (10Gb) - With CCC data partition is not copied.

3. With Finder i have copied data from Data-partition to HFS+
I'm trying to recreate folders like "Mojave"
i have copied Applications from Data to Applications in / HFS+
i have copied System/Library -> HFS+
I have copied Library , Vm , etc.

It's a Proof of Concept ...

For now HFs+ is still not working , but i feel i get close to success ....

I belive that if i'm able to recreate an old style scheme of folders, it will be able to boot from HFS+

That was my thought train too. I used ditto rather than finder as ditto preserves extended attributes and permissions and merges directories. Doing that, I was able to get the hfs+ install to boot.

My next step is to recreate the ‘- Data’ partition manually. That way I can either just extract Core.pkg with pkgutil, or use an older (or patched) version of OSInstaller.framework that doesn’t convert to APFS or split the disk. I have a dump of the install log, a dump of fs_usage events recorded during the install and a diff of a working and non-working (manually created) installs that I’m reading through. Over 5 GB of log files!

 

[toru173]

Ok, this is weird. I just installed to an HFS+ disk using the 10.13 installer (which I’ve done before), ditto’d the contents of /System/Library/Templates/Data/Device to / and /System/Library/Templates/Users to /Users. I meant to try to rebuild the caches, but missed the reboot and single user mode.

It booted straight up???

I’m going to try again

 

[toru173]

The system hangs on boot when replacing /usr/sbin/installer and OSInstaller in the 10.15 BaseSystem.dmg with those from 10.13.6. The install is successful and I can then ditto the files into the right places, but the device hangs on boot after the install is finished.

I'm trying to replicate my accidental success by installing from my active 10.13.3 install. If this works, I'll have some more info to go on.

Edit: It didn't work. I'm going back through my history to see what I did differently.

Conclusion: it’s still not working. Either I did something vastly different that time, or I didn’t erase the disk after the previous attempt. I can’t say and I can’t recreate my error. I didn’t save the terminal output because I wasn’t focusing on it. Ah well, back to the drawing board

 

[Fishrrman]

Once Mike Bombich and the CCC folks get their software working for Catalina, this job may become MUCH easier...

 

[toru173]

Once Mike Bombich and the CCC folks get their software working for Catalina, this job may become MUCH easier...

we're going to drop support for backing up macOS (Catalina and later) to HFS+ formatted volumes

https://bombich.com/blog/2019/06/06...em-volume-and-hfs-getting-out-system-business

 

[VerizonLover]

https://bombich.com/blog/2019/06/06...em-volume-and-hfs-getting-out-system-business

I have a fealing on 10.15 and later, CCC will just backup the Data partition in the volume group.

Though it does make one wonder how utilities like DiskWarrior (if it ever comes out) will cope with repairing the base (read-only) system image...