Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/startosinstall -converttoapfs NOĪ command which is issued in the Terminal. There is a way at least to bypass this automatic formatting in High Sierra: Mounting it via USB while booted off an older system renders the drive invisible. The side effect of this is that any older system than High Sierra, can't read the drive directly, unless it used shared via a networking protocol such as FTP. Note: when an SSD, or other solid state media (such as a USB stick or SD card) is used to install Mac OS 10.13 High Sierra or Mac OS 10.14 Mojave, it automatically chooses APFS. How to choose between APFS and Mac OS Extended when formatting a disk for Mac - Apple Supportĭiscusses using Disk Utility for the new file system.
Mac OS 10.13, released Septemhas introduced a new file system, APFS: Note, for hard drive model specific issues, see this tip:
