Bootable USB Stick - macOS X Catalina 10.15 - Full OS Install, Reinstall, Recovery and Upgrade. Please CHECK twice if your Mac model is compatible with this macOS!! If you are not 100% sure please message me your mac model and year and I can tell for sure if would work or not! The “Install macoS” option will install the macOS Catalina version on the USB flash drive. Before installing macOS, I wanted a clean slate so I erased the internal hard drive like so: Select the “Disk Utility” option and click the “Continue” button on the bottom to launch the “Disk Utility” application.
Can you install macOS Catalina on an external SSD connected to your Mac? Yes, it's definitely possible. However, since Apple initiated a relatively new partition scheme (APFS) with macOS High Sierra, the process is slightly different than with older versions of macOS. This article shows you how to set up a new SSD with macOS Catalina that you can boot from.
Why Installing macOS Catalina on External SSD?
macOS can be installed on an external storage device by default, such as HDD, SSD or USB flash drive. And this priciple also applies to macOS Catalina. For permance consideration, external SSD is much better becaus of faster reading and writing speed. The good news is that external SSD is much cheaper than before and the price gap is much smaller.
Now, the big question is why you don't want to install macOS Catalina on your main hard drive. After all, if you're upgrading to macOS Catalina, you want your Mac to boot to it all the time, don't you? Not necessarily. There are several reasons why you might not want to disturb your current installation, whether it's Catalina or an older version of macOS. Here are some possible reasons.
● You might want to try macOS Catalina without having to uninstall and roll back to Mojave or High Sierra if you change your mind. Uninstalling and rolling back to an older version of macOS is time-consuming and a tedious process that is prone to errors, so you may not want the hassles that come with it.
● Your Mac (Mostly Mac Mini or iMac) is built upon on a HDD and it runs slowly. You are looking for a way to boost the performance without untouching the internal drive.
● Since there are bound to be bugs in early versions of any new OS, you might want to avoid the hassle of having it as your default OS. This way, you can update it as new versions are released, then install it as your main OS when you're happy with the stability of the software.
● You may want to have the SSD run macOS Catalina on more than one machine. Since your SSD is essentially an external drive that is portable, you may want to switch it between one Mac and the other. Instead of installing Catalina on both, you have the flexibility of simply connecting the SSD to one of the Macs when you want to boot from it.
● It's also possible that you want to run a different set of apps and, therefore, need more memory. If you use a larger-capacity SSD, this will allow you to load a ton of heavy apps like Photoshop and so on, which might not be possible with your current hard drive because it is already full of data.
How to Pick up the Right External SSD for Catalina
Mac computers are made different from PCs. It has its own hardware port and unique standards. So not all external SSDs are suitable for Macs. To maximize the performance of SSD, it should be USB 3.0 compatible, if you have enough budget, ThunderBolt port is more welcome as it has much faster reading and writing speed. Besides, the volume should be 128 GB or larger. Below is a list of best external SSDs for Mac:
Further reading: How to check hardware port on your Mac
- Adata SD600Q External SSD 240GB (USB 3.2, $39.16)
- SanDisk 500GB Extreme Portable External SSD (USB-C, $84.99)
- Samsung X5 Portable SSD 500GB (Thunderbolt 3, $199.99)
- LaCie Portable SSD STHK1000800 1TB (USB-C, $178.31 )
- G-Technology 0G06053 Portable External SSD 1TB (USB 3.0, $189.95)
- WD 500GB My Passport Go SSD (USB 3.0, $69.99)
- Seagate One Touch SSD External 1TB (USB 3.0, $144.99)
Notice: The SSD you are going to use or purchase should be compatible with your Mac.
Preparation before Getting Started
To instal Catalina on external SSD, there are quite a few things you should set up previously. The preparatory steps are very important because if you don't get them right, the time spent on the rest of the process will be completely wasted and you'll have to do it all over again. For that reason, make sure you follow the steps exactly as outlined. macOS Catalina is built on a different drive partition scheme, the APFS file system. This was introduced in Catalina for Mac but it's been in iOS for quite some time. In an effort to unify its desktop and mobile operating systems, Apple has now rolled out the new system to both branches of its core OS.
1. Download Catalina DMG File: For macOS installation, you have to create a bootable Catalina USB first. To do this, you need to get a copy of the Catalina dmg file.
Download link: http://www.mediafire.com/file/ /macOS_Catalina_DMG.rar
2. Format External SSD to APFS: APFS is the file system that holds macOS Catalina installation. The SSD is formatted to exFAT when it is shipped. You can format the external drive to APFS with Disk Utility app.
Connect the SSD to your Mac and launch Disk Utility. Select the external drive in the left-side panel and click Erase. In the pop-up, name your drive, select APFS, and GUID Partition Map.
3. Backup important data on your Mac: To avid data loss, it is highly recommended backing up your important data on internal SSD with Time Machine or Cloud Drive.
How to Create macOS Catalina Bootable USB Installer
After completing the above preparation, it is time to get into the part for creating a bootable Catalina USB installer. This can be done easily with the help of UUByte DMG Editor, a cross-platform program for making bootable USB drive from macOS dmg file.
Step 1: Please download UUByte DMG Editor on a PC or Mac and follow the on-screen tips to install this utility on your computer..
Step 2: Plug in an external USB flash drive and eject other USB devices at the same time. Now, open UUByte DMG Editor and click Burn tab.
Step 3: In Burn page, click Browse button to add macOS dmg file you downloaded to the program. After a few seconds, you can see the USB drive in secord field.
Create Catalina Usb Install
Step 4: Set a name for the new volume and click Burn button to start writing Catalina DMG file to USB drive. The file is around 8GB so it takes about 10 minutes to finish the task. Please be patient!
Creating macOS Big Sur install USB on Windows 10 is simple with the help of UUByte DMG Editor. It is one of the best tools for managing DMG file on a Windows PC.
How to Install Catalina on External SSD
You have done all the crucial steps in above part and the final step is how to install macOS Catalina on External SSD. This process is quite simple.
First, connect the SSD to your Mac. Then restart your Mac and hold the Option key until you see the Apple logo. In the Startup Disk, click the external drive name.
When the boot resumes, you should boot into macOS Catalina installation wizard. At this stage, you should pick up the external SSD to install Catalina.
Another way to boot Catalina is from System Preferences. Here, go to the Startup Disk section, select your external SSD, and then hit Restart. Do not hold the Option or Alt key down if you're using this method.
Troubleshooting If Catalina Installation Failed
USB not bootable: If the USB drive is not showing up in Startup Manager, this means the USB drive is not recognized as a bootable device. Please download Catalina DMG file from another source and burn it again with UUByte DMG Editor. Sometimes, the partition table is missing in corrupted or damaged dmg file.
Install Catalina Usb
Can not boot into Catalina partition after installation: On latest T2 chip, Mac does not allow booting from external storage device by default. You have to enable 'Allow booting from external media' in Startup Security Utility, where you can launch it in macOS Recovery by pressing and holding Command + R immediately at startup.
Conclusion
Once you have macOS Big Sur installer USB ready, you can insert it into any Mac and run the program to install Apple's latest desktop operating system. Big Sur is officially coming in the fall and has a ton of updated features on nearly all fronts, including the OS interface, Safari, Siri, Messages for desktop, etc. But you should also know that since the currently available DMG is only a public beta tester version, it is bound to have bugs and other issues. If you're on the beta program, you can use the feedback app to let Apple know what the issue is. Unfortunately, that also means that there's nothing you can do about it if you're not on the beta program.
Apple hasn’t shipped operating systems on physical media in a full decade, but there are still good reasons to want a reliable old USB stick for macOS Catalina. Luckily, it's not hard to make one—either with a handy graphical user interface or some light Terminal use. Here's what you need to get started:
- A Mac that you have administrator access to. We've created a USB stick from both Mojave and Catalina, but your experience with other versions may vary.
- A 16GB or larger USB flash drive or a 16GB or larger partition on some other kind of external drive. A USB 3.0 drive will make things significantly faster, but an older USB 2.0 drive will work in a pinch; 8GB drives worked for Mojave and older versions of macOS, but the Catalina installer is just a little too large to fit.
- The macOS 10.15 Catalina installer from the Mac App Store (in High Sierra or older macOS versions) or the Software Update preference pane in Mojave. The installer will delete itself when you install the operating system, but it can be re-downloaded if necessary.
- If you want a GUI, take a look at Ben Slaney's Install Disk Creator from MacDaddy. There are other apps out there that do this, but this one is quick and simple.
If you want to use this USB installer with newer Macs as they are released, you'll want to periodically re-download new Catalina installers and make new install drives. Apple rolls support for newer hardware into new macOS point releases as they come out, so this will help keep your install drive as universal and versatile as possible.
AdvertisementThere's also one new consideration for newer Macs with Apple's T2 controller chip—as of this writing, that list includes the iMac Pro, the 2018 Mac Mini, the 2018 MacBook Air, and 2018 and 2019 MacBook Pros, though Apple keeps an updated list here. Among this chip's many security features is one that disallows booting from external drives by default. To re-enable this feature, hold down Command-R while your Mac reboots to go into Recovery Mode and use the Startup Security Utility to 'allow booting from external media.' If you're trying to install an older version of macOS, you may also need to go from Full Security to Medium Security to enable booting, but if you're just trying to install the current version of macOS, the Full Security option should be just fine. And if you're just doing an upgrade install rather than a clean install, you can run the Catalina installer from the USB drive from within your current installation of macOS, no advanced tweaking required.
The easy way
Once you've obtained all of the necessary materials, connect the USB drive to your Mac and launch the Install Disk Creator. This app is basically just a GUI wrapper for the terminal command, so it should be possible to make install disks for versions of macOS going all the way back to Lion. In any case, it will work just fine for our purposes.
AdvertisementInstall Disk Creator will automatically detect macOS installers on your drive and suggest one for you, displaying its icon along with its path. You can navigate to a different installer if you want, and you can also pick from all the storage devices and volumes currently connected to your Mac through the drop-down menu at the top of the window. Once you're ready to go, click 'Create Installer' and wait. A progress bar across the bottom of the app will tell you how far you have to go, and a pop-up notification will let you know when the process is done. This should only take a few minutes on a USB 3.0 flash drive in a modern Mac, though using USB 2.0 will slow things down.
The only slightly less-easy way
The Install Disk Creator is just a wrapper for the terminal command to create macOS install disks, so if you’re comfortable formatting your USB drive yourself and opening a Terminal window, it’s almost as easy to do it this way. Assuming that you have the macOS Catalina installer in your Applications folder and you have a Mac OS Extended (Journaled)-formatted USB drive (which is to say, HFS+ and notAPFS) named 'Untitled' mounted on the system, you can create a Catalina install drive using the following command.
sudo /Applications/Install macOS Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled
Install Catalina Usb
The command will erase the disk and copy the install files over. Give it some time, and your volume will soon be loaded up with not just the macOS installer but also an external recovery partition that may come in handy if your hard drive dies and you're away from an Internet connection. If you would like to create an install drive for a macOS version other than Catalina, just tweak the paths above to refer to Mojave or High Sierra instead.
Clean Install Catalina Usb Drive
Whichever method you use, you should be able to boot from your new USB drive either by changing the default Startup Disk in System Preferences or by holding down the Option key at boot and selecting the drive. Once booted, you'll be able to install or upgrade Catalina as you normally would. You can also use Safari, Disk Utility, or Time Machine from the recovery partition to restore backups or troubleshoot.