Back in the day when we bought OS X on discs, as long as you kept that disc, you always had a bootable installer just in case. Modern, downloadable versions of OS X create a on your drive, but it's always a smart idea to make your own bootable installer drive too.I recommend making one for Yosemite, on an external hard drive or USB thumb drive, for many of the same reasons I recommend: If you want to install Yosemite on multiple Macs, using a bootable installer drive can be more convenient than downloading or copying the entire installer to each computer. If you want to erase the drive on a Mac before installing Yosemite, or start over at any time, you can use a dedicated installer drive to boot that Mac, erase its drive, and then install the OS clean and restore whatever data you need from a backup. And if your Mac is experiencing problems, a bootable installer drive makes a handy emergency disk.Macworld also has bootable-install-drive instructions for, and.As with previous versions of OS X, it’s not difficult to create a bootable installer drive from the Yosemite installer, though the processes have changed slightly since Mavericks.
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I show you how, below. Keep the installer from being deletedLike all recent versions of OS X, Yosemite is distributed through the Mac App Store., if you leave the Yosemite beta installer in its default location (in the main Applications folder) when you install OS X 10.10, the installer will delete itself after the installation finishes. If you plan to use that installer on other Macs, or—in this case—to create a bootable drive, be sure to copy the installer to another drive, or at least move it out of the Applications folder, before you install.
If you don't, you'll have to redownload the installer from the Mac App Store before you can create a bootable installer drive. Create the Yosemite install drive: The optionsI’ve come up with three ways you can create a bootable OS X install drive for the Yosemite: using the installer’s built-in createinstallmedia tool; using Disk Utility; or performing the Disk Utility procedure using Terminal.The createinstallmedia method is the easiest; if you’re at all comfortable using Terminal, it’s the approach that I recommend you try first. (Note that the createinstallmedia tool doesn’t work under OS X 10.6 Snow Leopard—it requires OS X 10.7 Lion or later.)The Disk Utility method is the way to go for people who are more comfortable in the Finder (though it does require a couple Terminal commands), and it works under Snow Leopard, Lion, Mountain Lion, Mavericks, and Yosemite. The Disk Utility-via-Terminal approach is for the shell junkies out there.Whichever method you use, you need a Mac-formatted drive (a hard drive, solid-state drive, thumb drive, or USB stick) that’s big enough to hold the installer and all its data—I recommend at least an 8GB flash drive.
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That drive must also be formatted with a GUID Partition Table. (Follow to properly format the drive.) Your OS X user account must also have administrator privileges. Option 1: Use createinstallmediaStarting with Mavericks, hidden inside the OS X installer is a Unix program called, provided by Apple specifically for creating a bootable installer drive.
Jun 07, 2014 When Yosemite was first announced with all of its awesome features, I exclaimed on iDB’s group chat session that I would be installing the OS as soon as it was available for download.Sebastien quickly rebuffed my excitement and told me how unreasonable it was to install a beta OS on my main machine, and especially so while I’m out of the country.
If you’re comfortable using Terminal, createinstallmedia is a relatively simple tool to use.As mentioned above, the createinstallmedia tool works only in Lion, Mountain Lion, Mavericks, or Yosemite—you can’t create an installer drive this way while booted into Snow Leopard. If you need to create a Yosemite beta install drive while booted into Snow Leopard, you should use the Disk Utility instructions, below.
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Using the createinstallmedia command in Terminal IDG Here are the required steps:. Connect to your Mac a properly formatted 8GB (or larger) drive, and rename the drive Untitled. (The Terminal command used here assumes the drive is named Untitled.) Also, make sure the Yosemite installer, called Install OS X Yosemite.app, is in its default location in your main Applications folder (/Applications).
This means that if you moved it before installing Yosemite, you need to move it back before making your installer disk. Select the text of this Terminal command and copy it:sudo /Applications/Install OS X Yosemite.app/Contents/Resources/createinstallmedia -volume /Volumes/Untitled -applicationpath /Applications/Install OS X Yosemite.app -nointeraction.
Launch Terminal (in /Applications/Utilities). Warning: This step will erase the destination drive or partition, so make sure that it doesn’t contain any valuable data. Paste the copied command into Terminal and press Return. Type your admin-level account password when prompted, and then press Return. The Terminal window displays the progress of the process, in a very Terminal sort of way, by displaying a textual representation of a progress bar: Erasing Disk: 0%. 10 percent.20 percent.
The program then tells you it’s copying the installer files, making the disk bootable, and copying boot files. Wait until you see the text Copy Complete. (see the screenshot above), which could take as long as 20 or 30 minutes, depending on how fast your Mac can copy data to your destination drive.You now have a bootable Yosemite install drive.
If you like, you can rename the drive from its default name of Install OS X Yosemite, though I think it’s kind of a catchy name. Option 2: Use Disk UtilityYou’ll find Disk Utility, a handy app that ships with OS X, in /Applications/Utilities. Here are the steps for using it to create your installer drive. The procedure is a bit more involved with Yosemite than it was for Mavericks (which was itself a bit more involved than under Mountain Lion and Lion).
IDG Right-click (or Control+click) the Yosemite installer to view its contents. Once you’ve downloaded Yosemite, find the installer on your Mac. It’s called Install OS X Yosemite.app and it should have been downloaded to your main Applications folder (/Applications). Right-click (or Control+click) the installer, and choose Show Package Contents from the resulting contextual menu. In the folder that appears, open Contents, then open Shared Support; you’ll see a disk image file called InstallESD.dmg. Double-click InstallESD.dmg in the Finder to mount its volume.
That volume will appear in the Finder as OS X Install ESD; open it to view its contents. Several of the files you’ll need to work with are hidden in the Finder, and you need to make them visible.
If you're using one of these computers with,. you can install macOS Catalina. Your Mac also needs at least 4GB of memory and 12.5GB of, or up to 18.5GB of storage space when upgrading from OS X Yosemite or earlier.introduced in 2015 or laterintroduced in 2012 or laterintroduced in 2012 or laterintroduced in 2012 or laterintroduced in 2012 or lateriMac Pro (all models)introduced in 2013 or later. To upgrade from Lion or Mountain Lion, first upgrade to, then upgrade to Catalina.
To find your macOS version, Mac model, memory, and storage space, choose About This Mac from the Apple menu . If your Mac isn't compatible with macOS Catalina, the installer will let you know. If you're using OS X El Capitan v10.11.5 or later and your App Store preferences or Software Update preferences are set to download new updates when available, macOS Catalina will download conveniently in the background, making it even easier to upgrade. A will inform you when macOS Catalina is ready to be installed. Click Install to get started, or dismiss the notification to install later.
When you're ready to install, just open the file named Install macOS Catalina from your Applications folder.
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