Mac Os X Catalina Usb Installer

2/12/2022by admin

For an OS X El Capitan installation, the file gets saved as a disk image named 'InstallMacOSX.dmg'. To install, open the disk image and run the installer named 'InstallMacOSX.pkg'.

macOS Catalina is a hugely exciting upgrade for the Mac. In some ways, it’s like having a completely new computer. You may have already taken the plunge and installed it, or maybe you’re waiting to see how it settles down before you install it. But whichever camp you’re in, it’s a good idea to create a bootable installer for macOS Catalina. That way, if anything goes badly wrong with your Mac, you’ll be able to boot from the installer and get going again quickly.

  • To get started you’ll need the Install macOS Catalina application and an external storage drive larger than 8GB. A USB thumb drive is usually best for this, but you could also use an SD card or an external hard drive partition. How to create a macOS Catalina installer. 1) Download the Install macOS Catalina application from the Mac App Store.
  • A bootable version of the macOS Catalina installer is one of the often-overlooked tools a Mac user should have on hand before upgrading to or performing a clean install of Catalina. The bootable installer you create in this guide will be housed on a USB flash drive, but you can use any bootable device you may have lying around, including.

Why do I need a bootable installer for macOS Catalina?

There are a number of reasons for creating a bootable USB Mac installer.

  1. If you have more than one Mac, it allows you to install Catalina on all your other Macs without having to download it from the App Store each time.
  2. You may want to clean install Catalina, in which case you’ll completely wipe your startup disk and will need to boot from an external drive to do that.
  3. It’s good protection against a catastrophe striking your Mac’s startup disk, especially if you don’t have a stable internet connection. Normally, if you need to reinstall macOS, you can just boot from the recovery partition and do it from there. However, that means re-downloading the installer. So, if you don’t have an internet connection or it’s very slow, you need an alternative.

What should I use as a bootable installer?

You can use an external hard drive, an SSD or a USB stick. Anything that has at least 16 GB of free space. You’ll need to create a new partition (or container if it’s formatted as AFPS) for the installer so if you have data on it you need, you should copy it to another drive first.

How to create a bootable USB drive for macOS Catalina

Whoa! Not so fast. There’s one more thing you should do before you create the installer: clear out the junk on your Mac. Before you undertake any major task on your Mac, and especially before you install a new version of the operating system, you should clear out junk and old files you no longer need. I don’t normally recommend software tools, but in this case, the nest way to clear out the clutter is to use CleanMyMac X. It can scan your Mac at the press of a button, identify all the files you don’t need, and allow you to get rid of them with one more click. Here’s how to use it:

  1. Install, and launch CleanMyMac X — download a free edition here
  2. Choose Smart Scan from the list of utilities in the sidebar.
  3. Press Scan.
  4. When it’s finished, press Run to delete files immediately, or Review Details to see what it has found.

Once you’ve cleared out the clutter, you can go ahead and create your bootable installer. Here’s how:

  1. Launch the App Store app and search for macOS Catalina. (If you’re reading this before Catalina has been launched, you’ll need to use the public beta. You can sign up for Apple’s public beta program and download it here Apple Beta Software Program)
  2. When the results appear, click on Catalina, then click ‘Get’.
  3. Wait for it to download. When it’s finished, the installer will launch. Quit it immediately.

The installer has now been saved in your Applications folder. You can go ahead and check, if you like. You now have two options for creating the installer. If you’re comfortable with using Terminal, you can go ahead and jump to the instructions for that, below. If you’d rather not use Terminal, there’s a neat utility called Diskmaker X that will do it for you. All you need to do is download and install it and then, when you run it, point it to the macOS Catalina installer you just downloaded. There are full instructions on the download page.

How to create a bootable installer using Terminal

  1. Plug the USB stick, hard drive or SSD into your Mac.
  2. Go to Applications>Utilities and double-click Disk Utility to launch it.
  3. Select the disk you want to use for the installer and choose the Erase tab.
  4. Choose APFS or Mac OS Extended (Journaled) as the format and choose GUID partition map from the options, if it’s available.
  5. Give the disk a name and press Erase.
  6. When it’s finished, quit Disk Utility.
  7. Go to Applications>Utilities and double-click Terminal to launch it.
  8. Type:

    sudo /Applications/Install macOS Mojave.app/Contents/Resources/createinstallmedia —volume /Volumes/Untitled

    where ‘Untitled’ is the name of your USB stick or external hard drive

  9. Press Return and wait for the word Done to appear in Terminal.
  10. Quit Terminal

You now have a macOS Catalina installer on an external disk or USB stick. Eject it, unplug it and keep it safe. You can use it to install Catalina on any Mac that supports it.

One more step: update applications

Once you’ve used tour new installer to install Catalina on a Mac, it’s a good idea to update all your applications so that that are Catalina compatible. You can do this manually, from the App Store and by launching non-App Store apps and choosing check for updates, but that’s a long and tedious process. It’s much quicker and easier to use the updates in CleanMyMac X. Here’s how you do it.

  1. Launch CleanMyMac X.
  2. Select the Updater tool in the Applications section.
  3. Press Select All.
  4. Press Update.

And that’s it. You’re done. CleanMyMac X checks all your installed apps for updates and then updates them all.

Creating a bootable installer for macOS Catalina isn’t difficult. If you have a spare disk or USB stick and are comfortable using Terminal, you can do it right away. If you’d rather not use Terminal, use the Diskmaker X tool described above. Whichever method you use, make sure you use CleanMyMac X to clear out the junk on your Mac before you start, and use it again to update your applications when you’ve finished.

Customers get Software upgrades for Mac computers through the online app store ever since the release of macOS Lion. Be it a clean install or upgrade, Mac App store require you connect to the internet to download whole installation files. The online OS update is OK if you have stable broadband connectivity and enough bandwidth. Apple also provides an option for internet recovery of macOS if your computer fails to boot. But there are situations where you can’t download the OS from the Apple servers. Having a macOS offline installer or a bootable USB disk is the only solution in such scenarios.

Download macOS offline Installer

Installing macOS without internet requires a bootable USB disk. And you need to download a full-size macOS installer for making this disk. Hence, before anything, we will tell you how to download macOS offline installer directly from Apple to your Mac using a GitHub script.

Mac Os X Catalina Usb Installer Free

Download the gibMacOS script from this link and extract it to your Mac. From the extracted folder, run the script called gibMacOS.command — it will open the Terminal as shown below.

Installer

Wait for the script to fetch the macOS download catalogue from Apple. When the list is ready choose a number as per your OS option and press the Return/Enter key. You can use this script to download macOS Big Sur (11.1), Catalina (10.15), Mojave (10.14), and High Sierra (10.13.6). A new folder “macOS downloads” appears in the “gibMacOS-master” as you provide a download option, and the OS starts downloading as you can see in the video.

The OS gets downloaded as parts, PKGs, DMGs and other files. For macOS versions up-to Big Sur, you need to use another script “BuildmacOSInstallApp.command” in the main folder to join all the downloads and make the full macOS installer app. All you need is to drag and drop the downloaded macOS folder to the terminal window. The script will build the offline installer and save it to the same folder.

Mac os x catalina usb installer full

Mac Os X Catalina Usb Installer Update

You don’t need to use the second script if your choice is macOS Big Sur. Because, for macOS Big Sur you get a full-size installer from Apple in PKG format. Double-click and open the InstallAssistant.PKG to save the “Install macOS Big Sur.app” to the Applications folder.

Apart from this, some older versions of macOS are available for direct download from Apple (Sierra, EL Capitan, Yosemite) in DMG format.

How to make a macOS bootable USB installer

Usb

It is possible to create a backup macOS installer on a DVD or USB drive but later is the best choice. Most of the Macs these days don’t have DVD slots, and the installation through a disc is very slow. Hence we discuss only about making macOS recovery installer on a USB disc. For this you need a Mac and a USB pen drive of at least 8 GB space, and a third-party app called DiskMaker.

  1. First, download a copy of Disk Maker from the official website.
  2. Choose a version as per your requirement. For example, if you want make USB installer for macOS Catalina 10.15, download Disk Maker X 9.
  3. I use an MacBook Pro with High Sierra. Hence, I’m downloading disk maker X 7.
  4. The next step is to download full macOS installer from the App Store to your Applications folder.
  5. Run Disk Maker DMG installer and copy the app to the Applications.
  6. The application will automatically detect the downloaded macOS as shown in the screenshot. Select “Use this Copy” if you would like to proceed with it.
  7. Next is setting the USB pen drive for creating the bootable installer. Choose the third option ” An 8 GB USB Thumb drive.”
  8. The app will list all drives in your system. Pick the one you would like use as macOS USB installer.
  9. Ignore the warning message and proceed to Erase and Create macOS USB disk. Don’t forget to provide your admin password when it prompts.
  10. Keep checking notifications tab for progress. When it completes you will find Install macOS Mojave (or High Sierra) mounted to your desktop as a USB disk.
  11. That’s your backup. Unmount and keep the USB installer to a safe place.


Unfortunately, the above app is not compatible with macOS Big Sur 11 and above. Check the instructions on Apple website, the manual method to make macOS offline USB installer.

What is the alternative if I don’t have usable Mac at the moment?

This method is applicable when you have a Mac, and the internet recovery fails. But think about a situation when your only Mac stops to boot, and you don’t have USB installer or TimeMachine backup! Downloading MacOS DMG file might save you. If you have a macOS DMG, you can create bootable USB disk from a Windows PC — use a software like TransMac for this purpose.

Clean installing or restoring a Mac offline with USB pen drive

As said earlier, you could use the macOS USB installer to do a clean install or restore it upon a boot failure. Just connect the USB disk and press the Option/Alt Key when you hear the boot sound. The Mac will then display all the startup disks available.

Pick the USB drive starting with the label “Install macOS” and follow on-screen instructions to complete the installation. If you need, use the Disk Utility to format the drive for doing a clean install.

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