I just realized that there is a new version of Mac OS out. I thought it was out for a while, but I happened to stumble across that it was released today, apparently. To upgrade, I just went to the App Store – and that was pretty uneventful. There is plenty of advertising for it too:
OK, my first order of business is to update that little installation partition so that I can do a fresh install of this new OS if I ever need/want to. I wrote how to do this for a USB drive, and a hard drive for OS X Mavericks. Well, you might not be surprised the operation is pretty much identical, but there is some syntax difference.
This time, since I now know what’s involved, I’ll just put down this information here in one place, since the technique is almost identical.
Downloading the installer:
Just installing the new OS isn’t enough for what we need. After you’ve installed it, go back into App Store and click “Download”. This will download the full installation media and put it into /Applications/ – instead of simply installing the OS.
Creating an install partition for OS X Yosemite:
If you don’t already have an install partition, then I think you need to re-install the OS and configure a partition during setup. During setup, you should create an 8GB partition for the installation files to be installed. That should be enough for a while. OS X Mavericks with a little over 4GB and OS X Yosemite is a little over 5GB.
Either way, I’ll assume you have a separate hard drive partition where you can put the installation media. The first thing to do is go into Disk Utility, erase the partition. You can calls yours whatever you want, but for simplicity, I’m calling the hard drive partition “hddInstall”. We’re going to need that name in a minute:
Assuming you’ve finished downloading the installation source (which should now be in /Applications/Install OS X Yosemite.app) – and assuming your 8GB partition is called “hddInstall”, run this command to make that partition bootable, and to copy the installation media to it:
sudo “/Applications/Install OS X Yosemite.app/Contents/Resources/createinstallmedia” –volume /Volumes/hddInstall –applicationpath “/Applications/Install OS X Yosemite.app”
which looks like this:
this took just a few minutes to run. Now, in Disk Utility, I can see the bootable media:
Now, if I wanted to re-install the operating system (and even completely re-format “Mini Mac HD”, my main hard drive partition – I can change the Startup Disk (in System Preferences):
and from there, I can boot to the installation media and kick off a fresh install if I want:
Creating an install USB drive for OS X Yosemite:
The good news is the steps for this are exactly the same – except that you format the USB drive, and the command is different for copying the installation over to the USB. So first go into Disk Utility and erase the USB drive – and in my case, I’m calling it “usbInstall”:
Now, again assuming that you have downloaded Yosemite and it’s in /Applications, and assuming that your USB flash drive has been formatted and named to “usbInstall”, you can run this command to make it bootable and copy the installation media:
sudo “/Applications/Install OS X Yosemite.app/Contents/Resources/createinstallmedia” –volume /Volumes/usbInstall –applicationpath “/Applications/Install OS X Yosemite.app”
which looks like this:
This took considerably longer – perhaps :20+ minutes maybe? Now, back over in Disk Utility, we can see this as a formatted, bootable flash drive now:
Now, if you were to go into Startup Disk (in System Preferences), you now have another boot option:
By the way, how is OS X Yosemite?
In my opinion, it’s pretty nice. The UI is much “flatter”, like the new iOS. It has the same look/feel now of an iPad or iPhone. The tray at the bottom is different I guess, but yeah, it’s nice – and pretty, as Mac OS usually is: