What should I do if one or more volumes are not mounted in a container?

Before making any changes to your system SSD on macOS, it's essential to back up your data. Always use Time Machine or another backup method to ensure you can restore your data if something goes wrong. Here’s how you can safely resize your system SSD:

1. Reboot in Recovery Mode:

- For Intel Macs: Restart your Mac and hold down `Command + R` to start in Recovery Mode.

- For Apple Silicon Macs: Turn off your Mac, press and hold the power button until you see the startup options window, then click the gear icon labeled "Options" to enter Recovery Mode.

2. Use Disk Utility: Once in Recovery Mode, open Disk Utility. Before attempting to resize your partition, run First Aid to check and repair any errors on your disk. This helps ensure that the file system is healthy, which reduces the risk of problems during the resizing process.

In conclusion, resizing the system partition on macOS into multiple disks is generally not as beneficial as it might be in Windows environments, where partitioning disks into multiple volumes is more common. In macOS, the APFS file system is designed to handle storage management efficiently without the need for multiple partitions, which simplifies system management and reduces the risks associated with partitioning.

If you are comfortable using Terminal, open a Terminal session and enter this command:

diskutil list

Post the results here so we can see the complete structure of your drive.

A couple of FYI's:

• It is not advisable to Partition a macOS SSD; and if in fact you have used 448.36GB on a 500GB drive you can't partition it anyway, as there isn't enough free space.
• Even if there is enough free space, you would need to first reduce the size of the APFS container before you could partition the disk. And you cannot reduce the size of the container below the amount of used space.

What are you trying to achieve by partitioning the disk?

Yes, you can split external drives into as many volumes as you want. It's best to do this on a drive that doesn't have data on it to avoid losing any. Rebooting into Recovery Mode is only necessary for the system disk that macOS is loaded from.

etresoft wrote:

What are you trying to do? That is your data volume. You don't want to partition it. You can create additional volumes using Disk Utility. You don't want to partition the boot drive on a modern Mac.

I would go even further and say people should not create multiple partitions on any drive (even an external drive) because people almost always realize later on that one or more of those partitions are too small.

I completely agree that creating a new APFS volume is the way to go if a separate storage space is needed for data.

Do you need a partition? If not, use a volume.

houssam132 wrote:

i have this message "This container has 452,03 GB used space.

This container can’t be split, because one or more of its volumes is not mounted." can someone show how to fix this issue, i've been trying to fix for months, i saw every ytb videos and i still can't figure it out

for god sakes please help me guys

YouTube is for Taylor Swift videos, not tech support.

What are you trying to do? That is your data volume. You don't want to partition it. You can create additional volumes using Disk Utility. You don't want to partition the boot drive on a modern Mac.

We could give you more specific advice if we knew what your plan was for this new partition.

Is it possible to split an external drive into several partitions? Do I need to boot into recovery mode?