In the Disk Utility, the options for erase, restore and unmount are all unavailable (see picture 2), I imagine that’s because you normally cannot do any of these on the OS X Base System disk. This disk is also locked, so I cannot re-install High Sierra (see picture 3). I installed High Sierra as an update to Sierra in VirtualBox 5.1.23, following this blog. I’m still curious how to create iso for High Sierra, though. To download macOS high sierra from apple app store go to this link, it will automatically open the app store if you are opening the link on a mac. Download using the macOS High sierra patcher tool. Many have reported that the file downloaded from the official Apple app store is of only 20MB but the actual size of the setup of macOS High Sierra.
- Installesd.dmg Disk Utility High Sierra Base System Download
- Installesd.dmg Disk Utility High Sierra Base System Restore
- Installesd.dmg Disk Utility High Sierra Base System Diagram
- Installesd.dmg Disk Utility High Sierra Base System Sdn Bhd
- Installesd.dmg Disk Utility High Sierra Base Systems
Installesd.dmg Disk Utility High Sierra Base System Download
To perform a clean installation of macOS Sierra (basically, Mac OS X 10.12), I recommend using a bootable USB flash drive containing the macOS Sierra installer. Below are the steps I took to create the bootable USB flash drive and how I used it to install macOS Sierra.
Note: The macOS Sierra Disk Utility and installer appears to be more buggy and much slower than previous versions. The best advice for installing macOS Sierra is to try again and be very patient (if you expect an operation to complete in 5 minutes, then give it at least 50 minutes).
Download macOS Sierra Installer
The macOS Sierra installer is available from the Mac App Store. Run the “App Store” application, search for “macOS Sierra”, and download it. It will save the installer as an “/Applications/Install macOS Sierra.app” file (about 4.97GB in size).
Note: If you run the macOS Sierra installer to upgrade your Mac, the downloaded file will be deleted automatically after the upgrade is completed. To keep that file, you will want to move it out of the Applications folder so it won’t be deleted after an upgrade. Launch the “Terminal” application and run this command to move the downloaded installer to your user’s “Downloads” folder:
sudomv/Applications/Install macOS Sierra.app/ ~/Downloads/
If you are paranoid (doesn’t hurt), you can verify that the installer file was downloaded correctly by verify its checksum. Run the “Terminal” application and this command:
hdiutil verify /Applications/Install macOS Sierra.app/Contents/SharedSupport/InstallESD.dmg
# If successful, the last output line should read:
# hdiutil: verify: checksum of ‘/Applications/Install macOS Sierra.app/Contents/SharedSupport/InstallESD.dmg’ is VALID
Format USB Flash Drive
The macOS Sierra installer takes up 5.1GB of space on the USB flash drive, so you will need a flash drive with a capacity of 8GB or greater.
Note: If the flash drive is mounted under “/Volumes” successfully when you plug it in, you can skip the following steps to reformat the flash drive. This is because the script we run to create the bootable drive will reformat the flash drive as an initial step. Because I am paranoid, I recommend reformatting the USB flash drive manually anyhow.
Format the USB flash drive using these steps:
- Plug the USB flash drive into your Mac.
- Launch the “Disk Utility” application.
- On the left-hand pane, select the USB drive (not the partition under it, if any).
- Click on the “Erase” tab (or button at the top).
- Input a name like “Sierra” (this name will be overwritten later).
- Select “Mac OS Extended (Journaled)” for “Format”.
- Select “Master Boot Record” for “Scheme”.
- Click the “Erase…” button at the bottom. Click the “Erase” button in the warning popup dialog if you get one.
- The format operation may take several minutes to complete. (USB 2.0 and large capacity drives will take longer.) After the format completes, the partition will be mounted under “/Volumes/Sierra” (or whatever name you selected above).
- Note: Under macOS Sierra, the Erase function will fail if the USB drive’s partition is mounted. You can manually unmount the partition before running Erase. Or you can run Erase twice; the first time will unmount the partition and fail, and the second time will actually do the format (which will succeed).
- Close the “Disk Utility” application.
Create Bootable USB Flash Drive Installer
To create the bootable USB macOS Sierra installer, run the “Terminal” application and this command:
# The — volume value is the mounted USB flash drive partition; in this case, named /Volumes/Sierra
sudo/Applications/Install macOS Sierra.app/Contents/Resources/createinstallmedia — volume/Volumes/Sierra — applicationpath/Applications/Install macOS Sierra.app — nointeraction
# You will be prompted for your user’s administrative password.
Update: For macOS 10.14 Mojave (and its predecessor, macOS 10.13 High Sierra), the createinstallmedia command no longer requires the “–applicationpath” and “–nointeraction” flags, so omit them. The command becomes just “createinstallmedia –volume /Volumes/Mojave”.
Note: If the createinstallmedia command returns a “Failed to start erase of disk due to error (-9999, 0)” error, then your current Mac OS X version does not fully support the createinstallmedia tool. Instead, create the USB installation drive manually using instructions from Bootable USB Flash Drive to Install Mac OS X 10.10 Yosemite.
The “createinstallmedia” program will erase the USB flash drive, create a new partition named “Install macOS Sierra”, and copy the installation files to that partition. The output will look like:
Erasing Disk: 0%… 10%… 20%… 30%…100%…
Copying installer files to disk…
Making disk bootable…
Copying boot files…
The program will pause at the “Copying installer files to disk…” output line above. This step took 20–30 minutes with my Kingston 16GB USB 2.0 flash drive. Yours may take a shorter or longer time. I recommend giving it at least an hour, maybe two, before giving up.
Note: Mac hardware is very finicky about USB flash drives. Initially, I used a Corsair 32GB USB 3.0 drive; however, when I held down the Option key to try to boot with it, the Mac would freeze with a black startup screen. The Kingston 16GB USB 2.0 drive did not have this problem. So if you enounter issues (when erasing and copying) or weirdness (when booting), consider changing to another brand of USB flash drive. If you don’t have another drive, consider at least testing the flash drive to make sure it is not bad or corrupted (“First Aid” in “Disk Utility” is the minimum; google for more powerful tools).
Boot With USB Flash Drive
Note: I recommending connecting the Mac to its AC power adapter before beginning the macOS Sierra installation. The installation may take a long time (an hour or more) and you don’t want the battery to die in the middle.
To boot a Mac with the USB flash drive:
- Shutdown the Mac.
- Insert the USB flash drive.
- While holding the “option/alt” key down, turn on the Mac to display the boot Startup Manager.
- You should see one or more icons, one of which should be called “Install macOS Sierra” for the USB flash drive. (The internal hard drive may not be visible if it does not have a valid, bootable partition installed.)
- Note: If you don’t see the USB flash drive’s “Install macOS Sierra”, try removing and re-inserting the USB flash drive while viewing the Startup Manager screen. The USB flash drive should then appear after a few seconds.
- Select the “Install macOS Sierra” (with left/right arrow keys) and hit the “return/enter” key to boot from the USB flash drive.
It may take 5–10 minutes or longer to load the installer from the USB flash drive. Sometimes the progress bar may appear to be frozen… just be patient. I would give it at least 30–60 minutes to load before giving up.
Format the Hard Drive
When the installer finishes loading, you will see a “macOS Utilities” window appear. Do the following to format the internal hard drive:
- Click on the “Disk Utility” option and click the “Continue” button on the bottom to launch the “Disk Utility” application.
- On the left-hand pane, select the hard drive (not the partition under it, if any).
- Click on the “Erase” button at the top.
- Input a name like “macOS”.
- Select “Mac OS Extended (Journaled)” for “Format”.
- Select “GUID Partition Map” for “Scheme”.
- Click the “Erase…” button at the bottom.
- For SSD (Solid State Drive), the format operation may take less than a minute to complete. For mechanical hard drive, it may several minutes to hours, depending upon the size, speed, and condition of your hard drive.
- Note: Again, the Erase function will fail if the hard drive’s partition is mounted. You can manually unmount the partition before running Erase. Or you can run Erase twice; the first time will unmount the partition and fail, and the second time will actually do the format (which will succeed).
- Close the “Disk Utility” application.
Note: Now and then, I noticed the output of the Erase seems to erroneously double the size of the hard drive. For a 128GB hard drive, the graph shows 120.88GB macOS (in blue) and 120.37 GB Unformatted (in red). I think it is just a user interface bug because when I close Disk Utility and re-open it, the graph then only shows the 120.88GB macOS (in blue).
Install macOS Sierra
Back at the “macOS Utilities” window, do the following to begin the macOS Sierra installation process:
- Click on the “Install macOS” option and click the “Continue” button.
- The “macOS Sierra” installer’s splash screen will appear. Click the “Continue” button.
- Click on the “Agree” button to agree to the license. A popup confirmation window will appear; click on the popup’s “Agree” button.
- Select the hard drive and click the “Install” button.
Note: You may encounter strange hardware behavior. On my 13 inch Macbook Pro Retina, the macOS Sierra installer turned the fan on to maximum for the whole duration of the installation. Thankfully, once it finished and rebooted, the fan turned off and stayed off.
The macOS Sierra installer tries to be helpful by telling you how long it will take. Unfortunately, it lies. You should take whatever remaining time it tells you and multiple by 10 (for minutes) or 100 (for seconds). If it says “6 minutes remaining”, that could mean 60 minutes or one hour remaining. Worse, if it says “6 seconds remaining”, you may be staring at that message for 600 seconds or one hour.
The best solution is to be patient. Go grab a bite to eat and watch a movie. Take a long nap or better yet, sleep your 8 hours. I would wait at least 4 hours before giving up.
Note: You can display the installer’s log window (using the menu or pressing Cmd+L). I didn’t find this helpful at all. Even for a successful install, numerous errors are logged; I don’t know what is a critical or non-critical error. And often, you won’t see a progress/status log output for a long time, easily 20–30 minutes. Not seeing any new log statements does not mean that the installer froze. So the logs didn’t do anything for me.
What Does Giving Up Mean?
Giving up means you have accepted defeat. The next step is to retreat and try again. Some suggestions on how to proceed:
- Reset your Mac by doing the following:
- Reset the SMC (see step 3 under the “Reset the SMC on Mac notebook computers” section).
- Reset the NVRAM (aka PRAM).
- Run the Apple Hardware Diagnostic or Test to make sure you don’t have a hardware failure.
- Finally, retry the macOS Sierra install.
- Use a different USB port on the Mac.
- Use another brand of USB flash drive.
- Delete and re-download the macOS Sierra installer (especially if you downloaded it a long while ago). Even if the checksum is okay, you may want to re-download in case there is a newer version of the installer with a bug fix for your very problem.
- Download an older Mac OS X version, say Mac OS X 10.11 El Capitan, install that, and then upgrade to macOS Sierra. If you know the Mac OS X version which came with your Mac originally, consider downloading (if you still have access) and installing that version first.
- Use the Mac Recovery System to download and install the original OS version that came with your Mac. Then upgrade from that to macOS Sierra.
- Buy a more recent model Mac (at most a couple of years old). It may be that your current Mac is too old or slow to support macOS Sierra. It’s okay to keep running an old Mac OS version. (For example, if I had a Core 2 Duo Mac, I would not run anything later than Mac OS X 10.9 Mavericks on it.)
Hopefully, this post will help you to do a fresh installation of macOS Sierra.
Some info above taken from:
OS X Base System is the recovery partition (used to install OS X without a CD).
To use it just boot into Recovery Mode by pressing Command+R when starting the system.
You’re going to want to use disk utility and format Macintosh HD.
How do I uninstall OS X base system in Disk Utility?
Removing the partition with Disk Utility by formatting the disk
- Boot the Mac from a recovery DVD, USB key, or an attached drive.
- Launch Disk Utility.
- Right-click on the Disk (not the partitions) and select “Erase”
- Select the default Mac OS Extended (Journaled) as the file system, and give the drive a name.
Should I erase my OS X base system?
Should I erase OS X Base System? Answer: A: Answer: A: There is no need to erase The Base System.
How do I unlock a disk on a Mac?
How to unlock the Recovery HD on OS X Lion
- Restart Mac, press and hold Command + R keys down until a menu appears on the screen.
- In the Menu, choose ‘Disk Utility, next click the button ”
- In the Utility menu, choose your Startup volume which in most cases is called Macintosh HD.
How do I restore my Macintosh HD?
How to restore your Mac from a local backup
- Restart your Mac.
- While the startup disc is waking up, hold down the Command and R keys simultaneously.
- Click on Disk Utility.
- Click Continue.
- Select your Mac’s hard drive.
- Click the Restore tab at the top of the Disk Utility window.
What is Ox base system?
What is the ‘mac os x base system’ disk image on my help, restored macintosh hd to system. Os x base system is the recovery partition (used to install os without jan 22, 2014 examine disk utility.
Could not find installation information for this machine?
If you are installing mac os on a fresh Hard Drive then rather pressing cmd + R on startup, you need to press and hold only alt/opt key on system startup. In Recovery Mode you have to format your Disk using Disk Utility and Choose OS X Extended (Journaled) as drive format before you click Reinstall OS X.
Why can’t I erase my disk utility?
Select Disk Utility from the startup menu, and you can erase your startup drive securely. You’ll save a little time if you do an erase without overwriting, then reinstall OS X, then Erase Free Space with an overwriting option. After you boot, launch Disk Utility, select the startup volume, and click the Erase tab.
How do you wipe a Mac?
How to Wipe a Mac Hard Disk Drive (HDD)
- Make sure your Mac is turned off.
- Press the power button.
- Immediately hold down the command and R keys.
- Wait until the Apple logo appears.
- Select “Disk Utility” from the OS X Utilities list.
- Select the disk you’d like to erase by clicking on it in the sidebar.
How do I reformat my imac?
Step 3: Reformat your hard drive
- Restart your Mac.
- While the startup disc is waking up, hold down the Command+R keys simultaneously.
- Select Disk Utility.
- Click on Continue.
- Click on View.
- Click on Show all Devices.
- Select your Startup disk (it is probably named “Apple SSD” or something similar).
What is recovery mode Mac?
To use Recovery Mode, reboot or start your Mac and hold the Command and R keys simultaneously on your keyboard as soon as you hear the familiar startup chime. Keep holding as your Mac boots, which may take a few moments depending on its specific configuration.
How do I unlock my Macintosh HD password?
Use Recovery Mode
- Turn off your Mac.
- Press the power button whilst holding Command + R.
- The Mac will boot into Recovery Mode — when you see the load bar appear you can let go of the keys.
- Select ‘Disk Utility’ and press Continue.
- Go to Utilities > Terminal.
- Enter ‘resetpassword’ and press the Return key.
How do I remove encryption from my hard drive Mac?
This will remove password protection from the target drive.
- Connect the drive or volume you wish to decrypt to the Mac.
- Select the external drive (either from the hard drive or the Finder, or from the Devices menu in the Finder sidebar) and right-click on the drive icon, then choose “Decrypt ‘DriveName’…” from the list.
How do I restore a Mac partition?
Deleting a hard drive partition on Mac
- Step 1: Open Disk Utility.
- Step 2: Click the partition that you wish to delete under the logical volume.
- Step 3: Click the Erase tab and make sure Mac OS X Extended (Journaled) is selected.
- Step 4: Click the Erase button.
- Step 5: Click the logical volume.
How do I get to OSX utilities?
How to Repair a Mac Boot Disk with Disk Utility in Mac OS X
- Reboot the Mac and hold down Command+R to boot into Recovery, or hold down OPTION.
- Select “Recovery HD” at the boot menu.
- At the Mac OS X Utilities screen, select “Disk Utility”
- Select the boot volume or partition from the left menu and click on the “Repair” tab.
How do I do a clean install of OSX?
So, let us begin.
- Step 1: Clean up your Mac.
- Step 2: Back up your data.
- Step 3: Clean Install macOS Sierra on your startup disk.
- Step 1: Erase your non-startup drive.
- Step 2: Download the macOS Sierra Installer from the Mac App Store.
- Step 3: Start the Installation of macOS Sierra on the Non-startup drive.
What does restore disk utility do?
WARNING: When you restore one volume to another, all the files on the destination volume are erased. Before you restore a volume, copy any files on the destination volume that you want to save to a different volume. In the Disk Utility app on your Mac, choose View > Show All Devices.
What does OSX mean?
Installesd.dmg Disk Utility High Sierra Base System Restore
OS X is Apple’s operating system that runs on Macintosh computers. It was called “Mac OS X” until version OS X 10.8, when Apple dropped “Mac” from the name. OS X was originally built from NeXTSTEP, an operating system designed by NeXT, which Apple acquired when Steve Jobs returned to Apple in 1997.
What is Macintosh HD on Mac?
Macintosh HD is categorized under ‘Hard disks’ so if you leave it checked, then Macintosh HD (or whatever you have named your hard drive) will remain visible. Each drive will have a unique icon visible on the desktop.
Can’t be installed on Macintosh HD?
From the “MacOS could not be installed on your computer” screen:
- Press and hold “option” key and click restart.
- In the “Startup disk selection” screen, use the arrow keys to select your main hard drive (not the MacOS update)
- Wait for your Mac to boot normally.
- Download the latest combo update directly from Apple.
How do I boot a Mac in Safe Mode?
Start the system in Safe Boot mode
- Restart the Macintosh. Press and hold the Shift key immediately after you hear the startup tone.
- Release the Shift key when the Apple logo appears. Safe Boot appears on the Mac OS X startup screen.
What does first aid on Mac do?
In Mac OS X, it is part of the Disk Utility program. In earlier versions of the Mac operating system, it is a separate program called Disk First Aid. It is a good idea to run First Aid or Disk First Aid once a month or so if you use your computer frequently to prevent major corruption to the files on your computer.
How do I restore my iMac to factory settings without CD?
How to Factory Reset an iMac Via the Recovery Partition. Restart the iMac and hold the “Command-R” keys while the computer reboots. Select and connect to a Wi-Fi network from the list if the iMac prompts you to do so. Choose the “Disk Utility” option from the list and click “Continue.”
How do I wipe and reinstall my Mac?
Select your startup drive on the left (typically Macintosh HD), switch to the Erase tab and choose Mac OS Extended (Journaled) from the Format drop-down menu. Select Erase and then confirm your choice. Quit out of the Disk Utility app, and this time choose Reinstall OS X and Continue.
How do I reinstall Mojave on Mac without disc?
How to Reinstall MacOS Mojave
Installesd.dmg Disk Utility High Sierra Base System Diagram
- Backup the Mac before going any further, do not skip making a full backup.
- Restart the Mac, then immediately hold down the COMMAND + R keys together immediately to boot into macOS Recovery Mode (alternatively, you can also hold down OPTION during boot and select Recovery from the boot menu)
Is Mac OS Sierra still available?
If you have hardware or software that isn’t compatible with macOS Sierra, you might be able to install the previous version, OS X El Capitan. macOS Sierra won’t install on top of a later version of macOS, but you can erase your disk first or install on another disk.
What is the most current Mac OS?
VersionCodenameMost Recent VersionOS X 10.11El Capitan10.11.6 (15G1510) (May 15, 2017)macOS 10.12Sierra10.12.6 (16G1212) (Jul 19, 2017)macOS 10.13High Sierra10.13.6 (17G65) (July 9, 2018)macOS 10.14Mojave10.14.4 (18E226) (March 25, 2019)
Installesd.dmg Disk Utility High Sierra Base System Sdn Bhd
15 more rows
What is the order of Mac operating systems?
Left to right: Cheetah/Puma (1), Jaguar (2), Panther (3), Tiger (4), Leopard (5), Snow Leopard (6), Lion (7), Mountain Lion (8), Mavericks (9), Yosemite (10), El Capitan (11), Sierra (12), High Sierra (13), and Mojave (14).