Reinstall Catalina Without Losing Data

I recently upgraded to Catalina (everything is running fine, no issues with the OS), but decided to do a clean wipe of the drive to start fresh. Normally, I'd just boot into recovery mode, erase 'Macintosh HD', then reinstall the OS. But with the upgrade to Catalina, I now have 'Macintosh HD' and 'Macintosh HD - Data'.

Whether you want to reinstall the latest Mojave or Catalina, the fear of losing data is real. However, you don’t have to worry about this. In this post, we will share steps that you can follow to install new macOS without losing data. Prep Work: What to do before Reinstalling macOS. To reset your MacBook Pro without losing data, click on the Apple menu and click on Restart. Follow the next steps as given below. Step 1: Hold the Command + R keys until the MacBook’s utility window hasn’t opened. Step 2: Select Disk Utility and click on Continue. Hold down Command + R until the Apple logo appears. When the options appear on screen, choose 'Restore From Time Machine Backup' and click Continue. The next screen will show the words Restore.

11 May 2021 Update: I have discovered that an easy fix for this was replacing the RAM. I had bought non APPLE ram for my Mac Mini and although the RAM was working fine, I believe during the update process, Apple checks hardware and the RAM was causing issues. This has been confirmed by my local Apple Store and I have since replaced the RAM with another set from a different third party and everything is working smoothly.

On June 22, Apple introduced macOS Big Sur and till this very date I have mixed feelings on this recent release. However, I noticed that my beloved 2012 Mac mini is no longer supported. This means macOS Catalina will be the last Mac operating system to support my Mac mini. What was surprising to me, I had not updated my Mac mini from Mojave to Catalina. So, I updated it, and this happened:

There are several solutions that were recommended, but none I found convincing. I did not want to lose any data, and I did not want to start from scratch on this Mac as It has been running for years and does all kinds of things and workflows that will be too time consuming to re-setup.

My solution

You will need:

  • Another Mac other than the one that has this issue (in my case 2016 MacBook Pro)
  • External drive (I used my Samsung T5 SSD) formatted in APFS
  • SuperDuper : best macOS backup app

Solution: Use another Mac to update from Mojave to Catalina. The entire process took 3 hours.

The following worked for me:

Step One: Make a SuperDuper backup of the Mac mini on the Samsung T5. Now your Samsung T5 is the replica of macOS that was running on your Mac mini.

Step Two:Connect the Samsung T5 to MacBook Pro. The Samsung T5 will show up as external hard drive on the MacBook Pro.

Step Three:Download the macOS Catalina on the MacBook Pro. It's an 8gb file so grab a drink or watch your favourite TV show.

Step Four: Run the Catalina installer on the MacBook Pro. When the installer asks which hard drive to install in, select the Samsung T5 external hard drive. The installation will take some time and your MacBook will restart many times. Once the installation has been successful, shutdown your MacBook and remove the Samsung T5.

Step Five: Boot Mac mini from the external drive by using Startup Disk option. The idea is to use the external drive to boot your Mac mini to confirm that the Catalina update is working on the Mac mini.

Step Six:Use SuperDuper to transfer from Samsung T5 to the Mac mini hard drive. You do this by backing up the Samsung T5 to the existing hard drive on the Mac mini.

Step Seven:Once the above SuperDuper process is complete, boot your Mac mini from your Mac mini hard drive using Startup Disk option

Step Eight:Enjoy Catalina without losing any data or reinstalling anything.

Reinstall catalina without losing data

This method worked for me. Should you require any clarification, please contact me on @MereCivilian or email me: [email protected]

Data

Summary: This page is about how to reinstall macOS in macOS Recovery mode. Based on if you want to keep the original data on the startup disk, you can either choose to clean reinstall macOS or to reinstall macOS without data loss.

Reinstalling macOS gives your Mac a fresh start especially when you are frequently bothered by some issues, such as Mac not turning on, Mac hanging on the beach ball, apps frozen on your Mac, slow performance, or pink screen on Mac. Most of the time, such issue results from some system-level problems, while reinstalling macOS can easily save your life.

• How to reinstall macOS on an M1 Mac?

How to reinstall macOS from macOS Recovery mode?

When you need to reinstall macOS on your Mac, macOS Recovery mode makes this process easy and quick. By the way, if you want to learn more about macOS Recovery mode, you can watch this video.

To reinstall macOS in macOS Recovery mode:

Step 1: Make sure your Mac is connected to a stable Internet within all the following steps.

Step 2: Identify it's an Intel or M1 Mac, and immediately do one of the followings.

  • Press and hold Command + Option + R.This allows you to reinstall the latest version of macOS that is compatible with your Mac computer from the internet.
  • Press and hold Shift + Command + Option + R. This option allows you to reinstall the macOS that came with your Mac, or the closest version still available.
  • Press and hold Command + R. This allows you to reinstall the version of macOS stored on your built-in recovery disk, including any updates that you installed.

• How to Boot into & Use M1 Mac Recovery Mode

Step 3: Release these keys when you see an Apple logo, spinning globe, or the Utilities window.

Step 4: Enter the requested password if you are prompted to enter a firmware password or the administrator's login password.

• Recover/reset your forgotten Mac password

How Do I Reinstall Macos Without Losing Data

• Mac won't accept correct password, what to do?

Step 5: Decide if you want to clean install the system, or just reinstall macOS without losing your original data.

Reinstall Catalina Without Losing Data

If you want to factory reset the Mac for selling or giveaway, or the startup disk becomes corrupted, you might want to erase the startup disk before reinstallation. This guarantees a fresh and clean installation as it wipes all your personal data on the disk.

• How to factory reset your Mac?

Reinstall Catalina Without Losing Data

• How to reset your M1 Mac to factory settings?

If you only want to reinstall macOS because the original operating system is not working as you expect, you might want to keep your personal data intact. In case files are deleted or lost by accident during macOS reinstallation, you should have a backup of your data or getting files off first.

Install Catalina Without Losing Data

• How to get files off a MacBook that won't turn on?

Step 6: Either after erasing the startup disk or getting files off the Mac, you can then go back to macOS Utilities and choose Reinstall macOS. Check this post to find all macOS versions and know which one you are going to reinstall.

Step 7: Follow the on-screen instructions and choose a disk to reinstall the OS.

  • If the internal startup disk is not showing up, or the installer says that it can't install macOS on your computer or volume, you might need to back up files and then erase your disk.
  • If the installer asks you to choose Macintosh HD or Macintosh HD - Data when installing macOS Catalina, choose Macintosh HD.

Other ways to install macOS

Apart from reinstalling macOS from macOS Recovery mode, you have other options according to your situations.

Reinstall Mac Os Catalina Without Losing Data

  1. Get released macOS versions or updates by App Store or Software Update preferences.
  2. Get macOS beta (such as macOS Monterey that might be buggy now) through Apple’s developer website.

Whatever your situation of reinstalling macOS is, you should always retrieve your data from the Mac before any further movement. After all, you can't tell if you want it back or not in the future.

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