Bootable USB Installers for OS X Mavericks, Yosemite, El Capitan, and Sierra First, review this introductory article: Create a bootable installer for macOS. Second, see this How To outline for creating a bootable El Capitan installer. DMG file is a compressed file format being used widely on Mac computer. ILamourCar Bootable USB Stick for mac OS X El Capitan 10.11.6 USB Flash Drive for Full OS Recovery, Upgrade Reinstall System Install USB 16GB, Green. 4.3 out of 5 stars. Get it as soon as Tue, May 25. FREE Shipping on orders over $25 shipped by Amazon.
I'm a bit confused by your post on what you are trying to do here. Are you trying to boot into Recovery Mode to install macOS to an external USB drive or are you trying to boot from a macOS USB installer to install macOS to the internal drive?
Here are the instructions for creating a bootable macOS USB installer:
Bootable El Capitan Installer
Make sure to carefully read the section regarding macOS 10.11 as there are extra steps required to extract the real installer from the downloaded .dmg archive to the Applications folder. After running the .pkg file from the mounted .dmg file you can then proceed to use the command line to create the bootable macOS USB installer itself.
Bootable Usb El Capitan
Macs are very picky about the drives used for booting a Mac plus the quality of many USB sticks is extremely poor so try using another USB stick especially a different brand.
When erasing the drive make sure to select the whole physical drive within Disk Utility and erase the physical drive as GUID partition and MacOS Extended (Journaled). The physical drive should be the top most item which is usually identified by the make & model of the drive itself.
El Capitan Bootable Usb Not Working
Aug 21, 2021 12:52 PM