Welcome to Mac OS recovery, brought to you by IBM. In this video, we'll be learning about the recovery partition and what services it offers. Let's get started, Mac OS comes with a hidden partition installed that's called macOS Recovery, it essentially replaces the installation discs that come with new computers. So it does offer a version of the operating system,you installed plus a few additional utilities. You can access it by restarting your Mac while holding down the R key. It may or may not ask you for an administrator password and once it boots up it will present you with this screen, which is just a small window saying macOS Utilities. The four options that macOS Utilities presents you with are Restore From Time Machine Backup, if you happen to back up your Mac that way. Reinstall macOS which will install the operating system, Get Help Online, which is a limited Safari browser window that let you have access to Apple Support documentation. And last, Disk Utility which helps us manage the storage on the device. What's nice about the Reinstall macOS option is that it's not an erase and install, it just replaces the OS files which doesn't touch the user directories. So if there's any issues with the operating system, you can reinstall them with a moderate level of confidence that none of the personal data is going to be compromised. Now, always, it's a good idea to have a backup, but worst case scenario, this option does exist. It should also be noted that this will reinstall the operating system that the computer shipped with, not what the most current operating system is. Let's go ahead and break down Disk Utility, Disk Utility offers a lot of functionality in managing the storage on your Mac. The things that you can do really break down into three areas, you can attempt to run first aid to resolve any issues, you can partition or create more volumes on the storage, or you can erase the drive altogether. In order to modify any of the volumes on the storage space, you'll need administrator access. And furthermore, if the disk is encrypted with filevault, you will need the filevault key in order to unlock the drive to be able to make modifications. In the event you wish to erase the hard drive there will be three options for you to pick from after the drive is erased, you get to choose how securely you would like that drive erased. On a standard erase, it's just like essentially dumping the entire contents of the storage into the trashcan and hitting empty data recovery is still pretty viable at that point in time. However, if you choose the middle option, it is essentially writing over the data three times which means the US Department of Energy standard for securely erasing magnetic media. The most secure option is writing over the data seven times, which means the US Department of Defense 5220-22M standard. If you need even further detail about the drive itself, you can use the info button in the top right hand corner to produce a list of as much information as you could possibly get about the drive. While Disk Utility has a lot of features, more often than not, it's used to re-partition any type of drive particularly the external hard drives out of the box, which don't usually work with Mac OS due to drivers. You can open it up in Disk Utility, select the drive, reformat it, which will get rid of any proprietary software or backup software that was on the disk and you can use it as normal. Now, all of these utilities are wonderfully helpful unless, of course, the hard drive or solid-state drive has been reformatted, in which case, the hidden partition that macOS Utilities exists on wouldn't be there. So what you can do in that case is what's called an internet recovery, you can access Internet recovery by booting holding option R. You'll see a little globe with a progress bar that indicates it is downloading the macOS Utilities. A couple of things to note here is that, one, it still will require an internet connection, which it will prompt for. And second, unlike the regular macOS Utilities which installs the operating system that came with the Mac, internet recovery will install the latest version that is compatible with your Mac. That'll do it for Mac OS recovery options, we'll see you in the next video.
