These advanced steps are primarily for system administrators and others who are familiar with the command line. You don't need a bootable installer to upgrade macOS or reinstall macOS, but it can be useful when you want to install on multiple computers without downloading the installer each time.
Download macOS
Find the appropriate download link in the upgrade instructions for each macOS version:
MacOS Catalina Bootable Installer (macOS Catalina DMG) Now that you have the “macOS Catalina.app” installer, you can upgrade multiple Macs to the latest version using the same file. However, if you are looking to perform a fresh installation, you need to create a bootable installer for Catalina. Oct 12, 2019 Otherwise, we share the original one from our another topic: Download MacOS Catalina Installer.DMG,.ISO,.APP without App Store. Step 2: Create a bootable macOS 10.15 Catalina.iso. In another specific instruction, we make it so easy to help you to do: How to Create Bootable MacOS Catalina.ISO and.DMG images in both MacOS and Windows. Jan 01, 2014 However, opening a.dmg to get whatever is inside really is as simple as double-clicking the.dmg file. If it's an app in the.dmg, it will be obvious when opened. Or, you could check at the site where you downloaded your.dmg file. That will likely give you actual steps for doing what you want to do.
- macOS Catalina, macOS Mojave, and macOS High Sierra download directly to your Applications folder as an app named Install macOS Catalina, Install macOS Mojave, or Install macOS High Sierra. If the installer opens after downloading, quit it without continuing installation.
To get the required installer, download from a Mac that is using macOS Sierra 10.12.5 or later, or El Capitan 10.11.6. Enterprise administrators, please download from Apple, not a locally hosted software-update server. - macOS Sierra downloads as a disk image that contains a file named InstallOS.pkg. Open this file and follow the onscreen instructions. It installs an app named Install macOS Sierra into your Applications folder.
- OS X El Capitan downloads as a disk image that contains a file named InstallMacOSX.pkg. Open this file and follow the onscreen instructions. It installs an app named Install OS X El Capitan into your Applications folder.
- Nov 18, 2019 A file with the DMG file extension is an Apple Disk Image file, or sometimes called a Mac OS X Disk Image file, which is basically a digital reconstruction of a physical disc. For this reason, a DMG is often the file format used to store compressed software installers instead of having to use a physical disc.
- DMG file provides some attractive features that allow securing password along with file compression. These virtual or physical Apple disks can be cloned from one to another. This is one of the powerful features of Mac. Tip: If you want to open and view DMG files of Apple Mac OS X so, you can try DMG Viewer tool. Why DMG Files Are Created?
Apple Dmg File
Use the 'createinstallmedia' command in Terminal
- Connect the USB flash drive or other volume that you're using for the bootable installer. Make sure that it has at least 12GB of available storage and is formatted as Mac OS Extended.
- Open Terminal, which is in the Utilities folder of your Applications folder.
- Type or paste one of the following commands in Terminal. These assume that the installer is still in your Applications folder, and MyVolume is the name of the USB flash drive or other volume you're using. If it has a different name, replace
MyVolume
in these commands with the name of your volume.
Catalina:*
Mojave:*
High Sierra:*
Sierra:
El Capitan: - Press Return after typing the command.
- When prompted, type your administrator password and press Return again. Terminal doesn't show any characters as you type your password.
- When prompted, type
Y
to confirm that you want to erase the volume, then press Return. Terminal shows the progress as the bootable installer is created. - When Terminal says that it's done, the volume will have the same name as the installer you downloaded, such as Install macOS Catalina. You can now quit Terminal and eject the volume.
* If your Mac is using macOS Sierra or earlier, include the
--applicationpath
argument, similar to the way this argument is used in the commands for Sierra and El Capitan.Use the bootable installer
After creating the bootable installer, follow these steps to use it:
- Plug the bootable installer into a compatible Mac.
- Use Startup Manager or Startup Disk preferences to select the bootable installer as the startup disk, then start up from it. Your Mac will start up to macOS Recovery.
Learn about selecting a startup disk, including what to do if your Mac doesn't start up from it. - Choose your language, if prompted.
- A bootable installer doesn't download macOS from the Internet, but it does require the Internet to get information specific to your Mac model, such as firmware updates. If you need to connect to a Wi-Fi network, use the Wi-Fi menu in the menu bar.
- Select Install macOS (or Install OS X) from the Utilities window, then click Continue and follow the onscreen instructions.
Learn more
For more information about the
createinstallmedia
command and the arguments that you can use with it, make sure that the macOS installer is in your Applications folder, then enter this path in Terminal:Catalina:
Mojave:
High Sierra:
Sierra:
El Capitan:
Learn how the Mac App Store beautifully showcases your apps and makes them even easier to find, and how Developer ID and notarization make it safer for users to install apps that you distribute yourself.
Mac App Store
The Mac App Store makes it simple for customers to discover, purchase, and download your apps, and easily keep them updated. The Mac App Store on macOS Mojave and later offers editorial content that inspires and informs. Organized around the specific things customers love to do on Mac, along with insightful stories, curated collections, and videos, the Mac App Store beautifully showcases your apps and makes them even easier to find.
Outside the Mac App Store
While the Mac App Store is the safest place for users to get software for their Mac, you may choose to distribute your Mac apps in other ways. Gatekeeper on macOS helps protect users from downloading and installing malicious software by checking for a Developer ID certificate. Make sure to test your apps with the macOS 10.15 SDK and sign your apps, plug-ins, or installer packages to let Gatekeeper know they’re safe to install.
Dmg File
You can also give users even more confidence in your apps by submitting them to Apple to be notarized.
Mac Logo
Is Dmg Specific To Apple Download
Do you take less dmg when facing the bombs. The Mac logo is designed to easily identify software products and hardware peripherals developed to run on macOS and take advantage of its advanced features.
Mac App Store | Outside Mac App Store | |
---|---|---|
App Distribution | Hosted by Apple | Managed by developer (with Developer ID) |
Software Updates | Hosted by Apple | Managed by developer |
Worldwide Payment Processing | Managed by Apple | Managed by developer |
Volume Purchasing and Education Pricing | Managed by Apple | Managed by developer |
Advanced App Capabilities (iCloud Storage and Push Notifications) | Available | Available |
App Store Services (In-App Purchase and Game Center) | Available | Not Available |
64-Bit | Required | Recommended |
App Sandboxing | Required | Recommended |