What are other volumes in a container and how to remove them?

When Apple released macOS High Sierra, it introduced a new file system, APFS, and brought lots of under-the-hood changes to the way your Mac stores data, but thankfully, we don't need to get into those. One thing we should talk about, though, is 'other volumes' in a container because it might be mentioned on screen from time to time, especially if you use the Optimize Storage feature.

What is other volumes in container on Mac

In HFS+, the file system replaced by APFS could split a disk into different partitions. APFS gets rid of the concept of partitions and replaces them with containers. But containers differ from partitions. As well as having multiple containers on a physical disk, a container can have multiple volumes. For example, in macOS, your startup container has the main boot volume — usually called Macintosh HD — as well as the Recovery volume, Preboot volume, and volume for virtual memory like swap files. 

Before we discuss what 'other volumes' in the container are, let's look at where the message appears in the Storage tab of About this Mac.

1. Click the Apple menu.
2. Choose About this Mac.
3. Select the Storage tab.

After a short time, when macOS has calculated it, you'll see a colored bar describing how your storage is allocated. Most of the time, the box looks like the image above. But sometimes, you'll see part of the box colored gray and the description 'other volumes in container.'

Those 'other volumes' are the recovery, preboot, and virtual volumes. If you see that message, the other volumes likely take up much more space than they should because something has gone wrong. Unfortunately, reclaiming the storage space isn't as simple as just getting rid of the other volumes since they are crucial to the OS.

How to delete other volumes in a container?

However, there are other ways you can fix the problem to free up space on your Mac or get rid of the other volumes in a container message. Let's look at the options. 

1. Get rid of purgeable space with CleanMyMac X

CleanMyMac X is one of our favorite tools for freeing up space as well as doing general maintenance on a Mac. Don't take our word for it, though — well-known tech blog iMore.com called CleanMyMac X 'the simplest way to keep your Mac clean.'

One of the new features in CleanMyMac X is the 'Free up purgeable space' tool in the Maintenance utility. This tool identifies space on your startup disk that contains files that macOS doesn't need but which are only deleted when your Mac is running really low on storage. If you want to release that space before then, you can't. Unless you use CleanMyMac X. Here's how it works:

1. Download and install CleanMyMac X (there's a free download available).
2. Open CleanMyMac X.
3. Choose Maintenance from the sidebar on the left.
4. Select the box next to Free Up Purgeable Space and click Run.
5. Wait. Identifying space that can be safely purged takes a few minutes, but it won't be too long.
6. When it's finished, you'll hear an alert and see a message telling you it's done. If there was a problem with other volumes in a container taking up too much space, it should now be fixed.

2. Create a new user account

Some Mac users have reported that creating a new user account allowed them to reclaim storage from other volumes in a container successfully.

1. Click the Apple menu and choose System Preferences.
2. Select the Users & Groups pane.
3. Click on the padlock and type in your admin username and password.
4. Click the '+' at the bottom left of the screen.
5. Select Administrator from the dropdown menu and enter details for the new account.
6. When you have created it, restart your Mac and log in with the new Administrator account.
7. Choose About this Mac from the Apple menu again and then click on the Storage tab.
8. See if the 'other volumes in this container' disappeared.

3. How to manage each volume using Terminal

Apple's Storage tab doesn't give many details on what's going on with your drive and those other volumes. To find out what volumes your drive consists of, let's run this Terminal command: diskutil list

Look at the breakdown and see if there are multiple Macintosh HD — Data volumes. If you've found the extra volume, probably that's the one that eats out your space. You can even see how much space it occupies. 

To delete this volume, follow the instructions:

1. Open Disk Utility on your Mac.
2. Select the APFS Volume you want to remove.
3. Click the Delete Volume button '-' in the toolbar. If the button is dimmed, the selected volume is in use, which means you can't delete it. To delete this volume, you need to enter Disk Utility in macOS Recovery. 

To start up from macOS Recovery, for an Intel-based Mac, press and hold Command-R when your Mac starts up. Release the keys when you see an Apple logo, a spinning globe, or some other startup screen. Go to Disk Utility from the Utilities window.

For a Mac with Apple silicon, press and hold the power button when turning on your Mac. Release it when the Startup Options window appears. Now, open Disk Utility and follow the steps above to delete Disk Utility other volumes.

4. Disable iCloud Content Caching

Content caching was designed with the aim of speeding up software updates. Helpful as it is, it may also add up to the size of Macintosh HD other volumes. To reduce it, turn off iCloud Content Caching by following these steps: 

1. From the main Apple menu, go to System Preferences > Sharing. 
2. Deselect Content Caching.
3. Alternatively, you can turn off iCloud Content Caching but choosing Only Shared Content from the dropdown next to Cache in the Content Caching pane.

5. Find and remove suspicious apps

Sometimes, the issue may be caused by the apps installed on your Mac. It may be either a legit app or even a malicious one. Either way, to get rid of the problem, hunting down such third-party apps and removing them may help. Here's how to do it: 

1. Open Activity Monitor from Applications > Utilities. 
2. Click Memory and look for the apps or processes that seem to use too much memory. 
3. Do a quick online research and click X to quit any of those you find suspicious. 

Once you've quit them, it's a good idea to uninstall third-party apps if you no longer need them. To do it, you'll have to go to the Applications folder and drag the app to Trash. Besides, finding and deleting app leftovers is necessary (read more on uninstalling apps completely here).

6. Erase your disk and reinstall macOS

If nothing else helps, erasing the disk and reinstalling macOS may be the only way to fix the 'other volumes in container' issue. Don't forget to back up your data first. 

To erase your disk:

1. Start up your Mac in the Recovery mode (press and hold Command-R on Mac's startup or power button as described above based on the Mac you have).
2. From the Utilities window, select Disk Utility and click Continue.
3. Select Macintosh HD in the sidebar of Disk Utility and click the Erase button.
4. Use Macintosh HD as the name. 
5. In the Format field, choose APFS or Mac OS Extended (Journaled).
6. Click Erase.
7. After the erase is complete, delete all the volumes that may be left in the sidebar — keep the Macintosh HD volume you just erased.
8. Quit Disk Utility. 

You will see the Utilities window again. Click Reinstall macOS and wait till it's done. The other volumes should be gone. 

7. Hardware solutions

If none of the above worked, it might be a hardware problem that led to the issue. There have been reports that unplugging USB devices and replacing the old battery may help reduce the size of Macintosh HD other volumes. Note, though, that to replace the battery, you'll need to book an appointment with the certified repair shop, but do it after the system notifies you that the battery is too old.

macOS has made lots of improvements to the way it deals with storage space on your Mac, partly due to the lower capacity of the SSDs found in most Macs compared with physical hard disks. However, sometimes, these features go wrong, and it's then that you may see the 'other volumes in a container' message. Happily, fixing the problem is not usually difficult, and it's even easier if you use the Free Up Purgeable Space tool in CleanMyMac X.