: Use Disk Utility to format your USB drive as Mac OS Extended (Journaled) with a GUID Partition Map . Name the drive MyVolume .
If you explore the DMG contents ( /Applications/Install macOS High Sierra.app/Contents/SharedSupport/InstallESD.dmg ), you'll find a hidden APFS snapshot mechanism that verifies the system volume during the conversion — a precursor to modern sealed system volumes in macOS. macos high sierra 10136 dmg full
If you are searching for a file, you are likely engaged in a specific, often frustrating, digital excavation. Unlike the modern macOS installers—which are essentially the size of a small hard drive and come as .app bundles—High Sierra represents an era where the DMG (Disk Image) was king. : Use Disk Utility to format your USB