Computers, Laptops & Tablets Apple How to Move Time Machine to a New Backup Drive Upgrade your external storage without losing any data By Tom Nelson Writer Tom Nelson is an engineer, programmer, network manager, and computer network and systems designer who has written for Other World Computing,and others. our editorial process Facebook Twitter Tom Nelson Updated February 21, 2020 Apple Macs iPad Tweet Share Email Eventually, you may decide you need more room for your Time Machine backups and want to move them to a larger drive. You may need more room for two reasons. The amount of data you store on your Mac has no doubt grown over time as you added more applications and created and saved more documents. At some point, you may outgrow the amount of space available on your original Time Machine hard drive. The other reason for needing more room is a desire to store more data history. The more data history you store, the farther back in time you can retrieve a file. Time Machine saves multiple generations of documents or other data as long as you have enough room to accommodate them. However, when the drive fills up, Time Machine purges older backups to provide room for the most current data. These instructions apply to devices running macOS 10.6 and later. Selecting a New Time Machine Drive With a Time Machine, drive size is more important than overall performance. Drive speed shouldn't matter for a backup drive that you're mostly using to store data without retrieving it, so you should look for the most storage you can afford. External enclosures are an excellent choice for Time Machine drives, allowing you to connect the drive to your Mac using Thunderbolt or USB 3 depending on your needs. USB 3 and later enclosures are by far the most popular and the least expensive of the enclosure options, and they are a good value for this use. Just make sure the enclosure is from a reputable manufacturer. Moving Time Machine to a New Drive Follow these steps to move your current Time Machine backup to a new, larger drive. Connect the new hard drive to your Mac, either internally or externally. External drives can connect to a USB, Thunderbolt, or FireWire port on the Mac. Start up the computer. Time Machine works with drives in Mac OS Extended (Journaled) formats and Xsan formats. If the backup drive you attach isn't compatible, the Mac will prompt you to erase it. With some OS versions, the Mac prompts you to reformat at this step. If not, you can format the drive using Disk Utility. Formatting the hard drive erases any data it contains. How you use Disk Utility to format your new hard drive depends on which edition of macOS you're using. The instructions are different for versions up to and including Yosemite and ones since El Capitan. Once you finish formatting the new hard drive, it mounts on your Mac's desktop. Right-click the new hard drive icon on the desktop and select Get Info from the pop-up menu. Make sure that Ignore ownership on this volume isn't active. To change it, click the padlock icon located in the bottom right corner of the window. When prompted, supply an administrator's username and password. You can now make the changes. Click the padlock again to save your changes. Transferring Your Time Machine Backup to a New Hard Drive Once you've set up the new drive, you'll need to transfer your old Time Machine backups to it. Here's what to do. Launch System Preferences by clicking the System Preferences icon in the Dock, or selecting System Preferences from the Apple menu. Select the Time Machine preference pane. Slide the Time Machine switch to Off or remove the checkmark from the Back Up Automatically box. Both perform the same function. Connect your original drive to your computer and drag the Backups.backupdb folder to the new drive. If asked, supply an administrator name and password. The copying process can take a while, depending on the size of your current Time Machine backup. Once the copying is complete, return to the Time Machine preference pane and click Select Disk. Select the new disk from the list and click Use for Backup. Set the Time Machine switch to On or check the box in front of Back Up Automatically.