The process takes 10–30 minutes.
Open (Applications → Utilities → Terminal) and run: create mac os x bootable usb installer from dmg
sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/macOS\ Installer --applicationpath /Applications/Install\ macOS\ High\ Sierra.app The process takes 10–30 minutes
: MyVolume (this makes the Terminal command easier to copy/paste). Format : Mac OS Extended (Journaled) . Scheme : GUID Partition Map . Click Erase and wait for completion. 2. Mount the DMG File Apple Support Communityhttps://discussions.apple.com create mac os x bootable usb installer from dmg
sudo dd if=~/Downloads/OSX_Mavericks.dmg of=/dev/rdisk2 bs=1m