Can you install High Sierra and not convert to APFS?

[Crash0veride]

In this scenario the SSD will end up still on HFS+ (as will the HDD)??? HS won't convert the HDD and CCC will clones the files but not change the filesystem - do I have that right?

Can/should I convert the SSD to APFS afterwards???

That's correct. I would just upgrade it on the drive. I mean you have a clone backup right? Just flash it back if it's unsuccessful. Your method just puts unnecessary large write to the SSD, shortening it's life (albeit slightly) and takes a lot longer. The only advantage I can see on the less likely chance it fails, you have zero down time (but overall more downtown due to CCC copy times).

 

[simonsi]

So better to keep the clone backup and just upgrade the SSD?

Clone back TO the SSD if required will still work fine as that would be Sierra running on APFS?

 

[trevoclark]

So what do you think would happen in an iMac with dual internal drives where one drive is an SSD with the OS, and the other is an HD for storage. They are not fusion-ed at all.

 

[blakis08]

Just installed High Sierra on my Late 2013 iMac with an external SSD (Mushkin Reactor 1TB) via Delock Thunderbolt dock and everything went smooth. Disk utility showed APFS when the upgrade finished.

 

[thingstoponder]

Yes, after High Sierra install open diskutility, right click the external drive and click "Convert to APFS" (only works on HFS+ partitions). Now whether converting HDDs is useful is a whole other topic of discussion.

Thank you.

I installed High Sierra today and just converted my two 1TB hard drives that are 99 percent full. It took about 15 seconds each which is astounding to me. For some reason I assumed it would take over an hour like it did when I enabled FileVault on them for the first time a few months ago.

Does converting file systems always work so quickly? I've never done it before.

 

[MacinMan]

Hey guys, I am familiar with the status of Fusion drives and APFS on initial upgrade. What I wanted to find out is after the install is complete and everything is working. Can I boot into recovery and then convert the fusion drive with disk utility, or is that not supported either, at this time? Thanks.

 

[Gmouse]

This is unclear in the Apple guidance - it says only HDD will not be converted which seemed to leave open the question of whether they could be converted at user request. I asked this on another Apple Forum and the view was that at this time no APFS option will be available at all for HDD.

fwiw, I just bought an external SSD for the purpose of using it as a boot drive for High Sierra and gradually move to that as my default. I will retain a Sierra bootable.

I was going to ask about external HDD, as my internal iMAC SSD was converted but my external HDD was not. I guess I don't understand why the new file system won't work on HDD, and why you couldn't convert them seamlessly after the fact (without destroying data or anything)...

 

[MacinMan]

I was going to ask about external HDD, as my internal iMAC SSD was converted but my external HDD was not. I guess I don't understand why the new file system won't work on HDD, and why you couldn't convert them seamlessly after the fact (without destroying data or anything)...

I was able to manually convert my 6 TB Plex Media drive to APFS after install, using Disk Utility and it worked without issues. Just trying to determine if I should try the Fusion drive now, or just leave it as is until apple adds support for it to be done on upgrade.

 

[wilee]

Can you please help with APFS conversion? My main SSD drive was not converted during stable release install and when I boot into recovery mode - APFS is greyed out too

I disabled encryption and have SSD drive only configuration on 2014 MBP 15" - what may be wrong?

Thanks!

 

[simonsi]

So what do you think would happen in an iMac with dual internal drives where one drive is an SSD with the OS, and the other is an HD for storage. They are not fusion-ed at all.

I test installed HS on a dual-partitioned SSD with an attached HDD. The non-boot SSD partition and HDD were both left as HFS volumes, only the SSD boot partition was converted to APFS

 

[Crash0veride]

Terminal command for install without filesystem upgrade for the final installer:

/Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/startosinstall --converttoapfs NO

Agree to the License Agreement and a reboot should start.

 

[Beau Slim]

Terminal command for install without filesystem upgrade for the final installer:

/Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/startosinstall --converttoapfs NO

Agree to the License Agreement and a reboot should start.

Nice. Worked perfectly for me. High Sierra went in without a glitch, and I can still mount my Mac partition from within Linux.

 

[jenzjen]

Can someone tell me the exact steps now that we're on 10.13.4 - I want to clean install via a USB stick (not an in place install from disk) and not convert to APFS

The problem is I've tried both of the following, which lots of websites cite ... but both methods show my disk as APFS once the HS is finished installing (even though I used DU from the USB installer to reformat my target drive to HFS)

I feel like something must have changed with 10.13.4 as to why this no longer works

sudo "/Applications/Install macOS High Sierra.app/Contents/Resources/createinstallmedia" --volume /Volumes/Untitled --nointeraction

sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ macOS\ High\ Sierra.app –agreetolicense –converttoapfs NO –nointeraction

 

[Fishrrman]

jenzjen -

I think you're using the wrong terminal commands in post 38 above.

First, you must create your bootable USB installer.
Have you done that yet?

If not, I recommend that you use the free "Boot Buddy" to create the installer. You can get it here:
https://sqwarq.com/boot-buddy/

You'll also need a USB flashdrive 8 or 16gb.
Pre-format it to Mac OS extended with journaling enabled.
Have your OS installer in the applications folder.
Then run Boot Buddy -- takes only a few clicks of the mouse. It will take a while to create the installer.

When done, boot from the flash drive.
You will see the OS installer first, but YOU DON'T WANT TO RUN IT.
Quit it.

Now open Disk Utility from the Utilities menu.
Choose to ERASE your internal drive. NUKE IT BACK TO ZERO -- Mac OS extended with journaling enabled.
Now, quit Disk Utility.

Open Terminal.
Enter this command:
/Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/startosinstall --converttoapfs NO

Agree to the license agreement and the install should start.
You'll probably get one or more reboots and the whole process will take some time.

If you try my advice, please come back and tell us how it went.

 

[jenzjen]

If you try my advice, please come back and tell us how it went.

Thank you - my curiosity led me to the solution, which is pretty much what you described. I was missing that I needed to run Terminal a 2nd time from the installer (1st time created the USB installer)

I created my USB installer after downloading the package from the app store
sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ macOS\ High\ Sierra.app

Rebooted holding option, select my USB installer then run disk utility to completely erase my Mac HDD selecting the Mac OS extended journaled file system (not APFS)

Close disk utility then go to utilities and terminal in the menu bar ... entered the following where "Mac" is the name of my just formatted Mac HDD
/Volumes/"Image Volume/Install macOS High Sierra.app"/Contents/Resources/startosinstall --volume /Volumes/Mac --converttoapfs NO --agreetolicense

 

[dwnldr]

Dear Friends !

As i see, im not the only one who is fighting with APFS and FusionDrive combo... I would like to kindly ask you for help.
Im using Apple products approx. 20years, but i wasnt in situation like this :

Yesterday, i tried to reinstall macOS on my iMac Late 2015 with 2TB FusionDrive as "always". Ive created bootable USBkey drive with installer, booted iMac from this USBkey and started installer. I was suprised, because in DiskUtility was possible to choose APFS filesystem for my FusionDrive. YES, i know, FusionDrives wasnt fully supported, BUT "Craig" mentioned, that support will be added later in HS updates. My opinion was, OK, this time has come, and i give a try. The formatting process ended with FAIL. Drive was wiped, but the process ended with error and Partition wasnt created. What next ? Reformatting to JHFS+, because the APFS donest seems to be fully compatible yet with FusionDrive. In the moment i pushed "FORMAT" button to JHFS+ the iMac restarted. Since this time im in troubles :

- If i run the machine, and try to boot from USBkey installer, the machine restarts in couple seconds of LOADING the content from USB (so i cannot get to installer screen, diskutility, etc...). iMac restarts immediately the "loading" slider reaches first "milimeter"

- I tried to run internet recovery, but this situation is the same. After download finishes and the setup screen should start, some messages (like in verbose mode) appers for some seconds = reboot

- i installed from my MacBook from upper mentioned USBkey a clean HS to SSD drive, connected to iMac and choosen this partition to load = reboot

The iMac is cca 6months old (buyed as new, so in AppleCare warranty), diagnostics tells that is everything OK and healthy. No parts should be damaged... My next step should be connecting iMac in TargetMode to Air and manage the HDD, but im missing Thunderbolt-Thunderbolt cable yet...

Maybe if you have som ideas, what should i try, because a would like to avoid from sending the new machine to disassembly in workshop etc...

Thank you very much !

 

[Fishrrman]

dwnldr -

You need to FORGET THAT APFS EVEN EXISTS.

If you have a fusion drive, erase it to Mac OS extended with journaling enabled (HFS+) and LEAVE IT THERE.

If you have a bootable USB flashdrive, I can't understand why the Mac won't boot from it.

Are you holding down the option key at boot time?

Do it this way:
- Power down ALL THE WAY OFF
- Insert the USB flashdrive into a USB port
- Press the power on button
- IMMEDIATELY hold down the option key and KEEP HOLDING IT DOWN until the startup manager appears
- Select the USB drive with the pointer and hit return.

Does this routine work?