In the drop-down menu under Partition Layout, choose 1 to create a single new partition. This won’t work for Yosemite, so we need to change it. In our case, our drive is brand new and formatted as a FAT volume with a Master Boot Record partition scheme. The partition scheme and volume properties of your flash drive will vary depending on manufacturer and previous configuration. With the USB drive selected, choose the Partition tab on the right side of the window. Note that you want to select the drive and not the volume. We’re using a SanDisk Cruzer flash drive, so in our case we choose 8 GB SanDisk Cruzer Media and not the default “No Name” volume. In Disk Utility, select the USB flash drive from the list on the left. Plug the drive into a Mac running OS X 10.7 Lion or higher and launch Disk Utility from the /Applications/Utilities folder. While it’s possible to create a separate partition for the Yosemite USB installer, it’s safest and easiest to use an empty drive or one that you don’t mind erasing. Grab a USB flash drive that’s at least 8GB in size. It will also launch the Yosemite installer app when the download completes. This will put a file called Install OS X 10.10 Developer Preview.app in your /Applications folder. You can now quit Terminal and eject the volume.Step 1: Obtain the Yosemite Developer Preview Installerĭownload the OS X Yosemite Developer Preview installer from the Mac App Store.

When Terminal says that it's done, the volume will have the same name as the installer you downloaded, such as Install macOS Monterey.

After the volume is erased, you may see an alert that Terminal would like to access files on a removable volume.

Terminal shows the progress as the volume is erased.

When prompted, type Y to confirm that you want to erase the volume, then press Return.

Terminal doesn't show any characters as you type.

When prompted, type your administrator password.

If the volume has a different name, replace MyVolume in the command with the name of your volume.

Each command assumes that the installer is in your Applications folder, and MyVolume is the name of the USB flash drive or other volume you're using.

Type or paste one of the commands below into Terminal, then press Return to enter the command.

Open Terminal, which is in the Utilities folder of your Applications folder.Plug in the USB flash drive or other volume that you're using for the bootable installer.

Os x yosemite download to usb