Running High Sierra GM on SSD formatted HFS+

[SteveRings]

So my High Sierra boot partition disappeared after HS GM install which is when I discovered there is no option to install without APFS.  Well, that maybe the future but I don't want it.  So, I removed it.

 

My setup is a dual boot with Win 8 (I use it about once a month, by accident).  My Mac boot disk is disk0s6, 70GB, and I have my user data on disk0s8, about 300GB, not the boot disk.  This division allows quicker restores and less-dangerous upgrades as the data is always safe.  You may need far more than 70GB depending on your applications so think about it before you do that split.

 

I mention that because you have to destroy your boot disk in order to revert to HFS+; having to restore all of your data every time is both tedious and a little more dangerous than having it safely housed away from what ever APPLE has decided is best for us this week.

 

So here are the steps:

 

1) Make a local USB Time Machine backup of your boot disk;  you can use a network version (make sure it is up-to-date!) but the restore will take HOURS.

2) Install the High Sierra GM onto a bootable USB device

3) Migrate your previous backup onto the new install (if your USB is too small, do step 4 before step 3)

4) Boot into Recovery; using DISK Utility, restore the USB install onto your HFS+ boot partition.

 

I'm staying on HFS+ as long as possible - the world is not ready for APFS and way too much stuff is affected without good alternatives. 

 

[snifferdog]

> there is no option to install without APFS

 

Would it be accurate to add: "when installing to an SSD"?  My understanding is that APFS is optimised for SSDs.

 

Edit: answered my own question:

 

https://support.apple.com/en-gb/HT208018

[pinarek]

there is no compulsive conversion to APFS if you install correctly.

 

there is a page where you can choose to install, by ticking a checkbox in a box, whether you want to install on APFS or not, i. e. as usual on HFS+.

 

No compulsion, but a selection ! I have read about "forced conversion" in several forums, it seems they don't know how to install High Sierra correctly.

[SteveRings]

The conversion CANNOT be avoided if you have flash storage.  I chose the box on Beta 1 and had HFS+ on my flash storage thru out the Beta but the GM has no such check box for flash storage.  If you get a box then you do NOT have Apple recognized FLASH storage.

 

Another option might be to cripple the KEXT for flash storage until after the install ... unfortunately, I'm out of town for two weeks so I'll have to get back to y'all about that ... 

[Guest ricoc90]

Alternatively you can deploy the HS installation directly onto your drive from within another mac or hack, by using the "startosinstall --converttoapfs NO" command OR change the FFM in your SMBIOS: http://www.insanelymac.com/forum/topic/324194-pre-release-macos-high-sierra/?p=2471719

[malgkas]

Alternatively you can deploy the HS installation directly onto your drive from within another mac or hack, by using the "startosinstall --converttoapfs NO" command OR change the FFM in your SMBIOS: http://www.insanelymac.com/forum/topic/324194-pre-release-macos-high-sierra/?p=2471719

Hi Everyone,

 

Just did upgrade on SSD drive running this command:

 

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

 

No problems noticed so far and macOS loads much faster than from APFS partition.

 

Thank for tip Ricoc90.