Reinstall from macOS Recovery
macOS Recovery makes it easy to reinstall the Mac operating system, even if you need to erase your startup disk first. All you need is a connection to the Internet. If a wireless network is available, you can choose it from the Wi-Fi menu , which is also available in macOS Recovery.
1. Start up from macOS Recovery
Some Mac users may require the ability to erase a disk or erase a hard drive from the command line on Mac OS, a task which is typically performed through the Disk Utility application from the GUI. The command line approach to disk erasure in macOS is a bit different and it requires precise syntax to insure that you are erasing the proper disk. Click Erase at the top of the Disk Utility window. Enter the name of this volume and choose Mac OS Extended (Journaled) format from the drop-down menu. You may need to enter your Apple ID for confirmation. When the process is complete, go the Disk Utility menu in the top left corner of your screen and select Quit Disk Utility. A reader preparing their Mac for sale has a well-meaning friend erase the startup volume. MacOS installer on a USB flash drive or a disk drive. To run Disk Utility, reinstall or wipe.
To start up from macOS Recovery, turn on your Mac and immediately press and hold one of the following sets of keys on your keyboard. Release the keys when you see an Apple logo, spinning globe, or other startup screen.
Command (⌘)-R
Reinstall the latest macOS that was installed on your Mac (recommended).
Option-⌘-R
Upgrade to the latest macOS that is compatible with your Mac.
Macbook Disk Utility Boot
Shift-Option-⌘-R
Reinstall the macOS that came with your Mac, or the closest version still available.
You might be prompted to enter a password, such as a firmware password or the password of a user who is an administrator of this Mac. Enter the requested password to continue.
When you see the utilities window, you have started up from macOS Recovery.
2. Decide whether to erase (format) your disk
You probably don't need to erase, unless you're selling, trading in, or giving away your Mac, or you have an issue that requires you to erase. If you need to erase before installing macOS, select Disk Utility from the Utilities window, then click Continue. Learn more about when and how to erase.
3. Install macOS
When you're ready to reinstall macOS, choose Reinstall macOS from the Utilities window. Then click Continue and follow the onscreen instructions. You will be asked to choose a disk on which to install.
- If the installer asks to unlock your disk, enter the password you use to log in to your Mac.
- If the installer doesn't see your disk, or it says that it can't install on your computer or volume, you might need to erase your disk first.
- If the installer is for a different version of macOS than you expected, learn about macOS Recovery exceptions.
- If the installer offers you the choice between installing on Macintosh HD or Macintosh HD - Data, choose Macintosh HD.
Please allow installation to complete without putting your Mac to sleep or closing its lid. During installation, your Mac might restart and show a progress bar several times, and the screen might be empty for minutes at a time.
![Macbook Disk Utility Erase Macbook Disk Utility Erase](https://www.askdavetaylor.com/5-blog-pics/mac-disk-utility-external-read-only-erase.png)
If your Mac restarts to a setup assistant, but you're selling, trading in, or giving away your Mac, press Command-Q to quit the assistant without completing setup. Then click Shut Down. When the new owner starts up the Mac, they can use their own information to complete setup.
macOS Recovery exceptions
The version of macOS offered by macOS Recovery might vary in some cases:
- If macOS Sierra 10.12.4 or later has never been installed on this Mac, Option-Command-R installs the macOS that came with your Mac, or the closest version still available. And Shift-Option-Command-R isn't available.
- If you erased your entire disk instead of just the startup volume on that disk, macOS Recovery might offer only the macOS that came with your Mac, or the closest version still available. You can upgrade to a later version afterward.
- If your Mac has the Apple T2 Security Chip and you never installed a macOS update, Option-Command-R installs the latest macOS that was installed on your Mac.
- If you just had your Mac logic board replaced during a repair, macOS Recovery might offer only the latest macOS that is compatible with your Mac.
If you can't get macOS Recovery to offer the installer you want, you might be able to use one of the other ways to install macOS.
Other ways to install macOS
- You can also install macOS from the App Store or Software Update preferences. If you can't install macOS Catalina, you might be able to install an earlier macOS, such as macOS Mojave, High Sierra, Sierra, El Capitan, or Yosemite.
- Or create a bootable installer disk, then use that disk to install macOS on your Mac or another Mac.
Partitioning a disk on a Mac is an effective way to organize your data into different categories. However, the main concern is that most external hard drives and USB keys come formatted for Windows, which is primarily for PCs. By default, a Mac runs a different file system, so it may bring issues while partitioning your disk on Disk Utility.
Macbook Disk Utility Erase Free Space
Hard drive partitioning is a common issue discussed in many tech forums. In a thread on Apple’s support forum, users complain that their Mac Disk Utility partition grayed-out while trying to partition their external hard drives.
Probably, you just bought your external hard drive and are eager to use it on your Mac. But somehow, you cannot access the Mac Disk Utility partition, so you can’t write data to the drive.
Fear not, we have a solution to this problem. In this post, we will guide you through a step-by-step process on how to restore a grayed-out Disk Utility partition. Free macbook storage cleaner. Many Apple users who have faced Partition grayed out in Mac issues eventually partitioned their external hard drives with the help of these fixes.
Why Partition Grayed Out in Mac (Plus Solution)
Problem 1: Sometimes, you cannot access the Mac Disk Utility partition because your hard drive doesn’t have sufficient space.
Solution: If you want to go ahead with the partitioning task, you need to create more space on your hard drive. In other words, you have to erase the data on your drive to create additional space. You can then format your hard drive using GUID Partition Table. After that, go ahead with your partitioning plans.
Important Note: Before formatting your hard drive, back up your most important files. Needless to say, the process will get rid of all the data on the disk, so you risk losing your files for good.
Problem 2: As mentioned earlier, external drives are usually not compatible with macOS, which may bring issues when you want to partition. In most cases, users choose the wrong partitioning option, and as a result, the Partition option in Disk Utility remains grayed out.
Solution: The right way you should follow when selecting a partition option is to choose the drive name within the list provided under Internal or External (depending on the device you want to partition). Your hard drive will be available on the left side of the Disk Utility pane.
How to Restore Grayed Out Disk Utility Partition: Format Your Hard Drive to Work with Mac
To format your external disk to be compatible with macOS, connect your hard drive to the Mac and follow these steps:
- Open Disk Utility by going to Applications, then select Utilities > Disk Utility.
- Choose the drive name within the list provided under ‘External’. If your hard drive is connected, it will show in the left panel of the Disk Utility. Highlight the disk and click the Erase button in the top toolbar.
- Wait for a window asking you to select the file system you want to use to format your external drive to pop up. For your case, you will select ‘Mac OS Extended (Journaled)’. But if you have plans to use your disk for both PC and Mac, then a better option is ‘ExFAT’. You can also rename your hard disk here to your desired name.
- Wait for the formatting process to complete. The process usually takes less than a minute, but it depends on the size of your hard disk.
- When done, confirm if the formatting was successful by right-clicking the icon for your disk on the desktop and then choosing Get Info. The information is available under Format.
If it reads “Mac OS Extended (Journaled)”, congratulations, you successfully restored the grayed-out Disk Utility and your hard disk is now compatible with macOS.
Partitioning Your Hard Drive on Mac
Now that you have prepared your hard drive to work with Mac, the next step is to partition it on your Mac by following these steps:
- Launch the Disk Utility app on your Mac and highlight the hard drive icon under ‘External’ (for external hard drives). If you choose any other drive, the partition option will become unclickable.
- Now click Partition on the top toolbar. A window that has partition information will pop up. On the left side of the window, look for the name and the volume size of your hard drive. The next step is to click add(+) button on the bottom of the window to create partitions on your disk. Allocate the desired volume size to each partition.
- Hit the Apply button and wait for a window asking you to verify your choices. Confirm the changes by clicking the Partition button.
- Wait for the process to complete. You can confirm if the process was successful on your desktop. You will see additional disk icons show
Pro Tip: If the main reason for partitioning your hard drive is to install Windows, Apple recommends that you use Boot Camp Assistant instead of Disk Utility. You should, however, note that you cannot use Disk Utility to erase a partition generated using Boot Camp Assistant.
What Else Can You Do to Resolve Common Mac Issues
If you are like many users, partitioning a hard drive on Mac may not be the only challenge you have had with your computer. Mac users have also reported slow performance, random freezes, and space issues. The best way to guarantee the best performance for your Mac is to scan and clean the computer. Outbyte MacRepair helps you to optimize your Mac for peak performance by checking for and cleaning up junk files, unnecessary apps, and other space hogs that may affect your Mac’s memory.
![Can Can](https://www.macobserver.com/tip/2006/06/diskutility_erase.jpg?x17707)
We hope the above solutions helped you to restore the grayed-out Disk Utility partition. As always, we would love to hear your success story. Share it in the comment section. Also, let us know if you experienced challenges during the partitioning process.
If you’re running into errors and your system is suspiciously slow, your computer needs some maintenance work. Download Outbyte PC Repair for Windows, Outbyte Antivirus for Windows, or Outbyte MacRepair for macOS to resolve common computer performance issues. Fix computer troubles by downloading the compatible tool for your device.
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