How do I fix storage issue on my MacBook Air?

For Apple Intel computers, use Disk Utility to erase an Intel-based Mac and then follow the instructions in How to reinstall macOS.

Before proceeding, make sure to create a Time Machine backup.

If you decide to go this route, I suggest not using Startup Assist to migrate everything back. 

Get yourself a good External Drive with at least 500 GB drive capacity

Start moving your pictures, music, videos and any other files that are large and un-need onto the external drive

What is presented in your Disk Utilities image is general very accurate

A sad reality is, the SSD Drive in this computer >> 128 GB Capacity << should have never been made available for purchase, by Apple

That size of Drive is way too small to doing anything meaningful in the way of storage

You can only " manage " the space that is available

That or purchase a new computer with a much larger Drive Capacity

Below is to compare your computer to mine running macOS 15.1 Sequoia

Follow on

Just notice > > 1 Not Mounted @ 72.63 GB

That seems Not normal to me

Would you please,  in Terminal application

Run this command and post back the results

diskutil list

alfankhoi4 wrote:

should I reinstall MacOS or factory settings?

Before going down that road

If you can determine which of the 2 Data Volumes is where your user account is actually located ??

It is possible to remove 1 of the data volumes with out having to Factory Reset

Suggest opening Disk Utilities and be sure to use the " Show All Devices "

Maneuver to the MacIntosh HD - Data volume

Take a screen shot of this and post back

Do the same for the Macintosh HD- data volume

We are trying to determine the Point Point of each

The one With the Mount Pointe of /System/Macintosh HD ?? is the one to keep

The one with the Mount Point of /Volume/Macintosh HD ?? can be remove in Disk Utilities

The are 2 APFS Macintosh HD - Data Volumes

One called Macintosh HD - Data @ 22. 5GB and another called McIntosh HD- data @ 10.3 GB

In this setup - the Macintosh HD - data volumes ( not partitions ) are where you User Account Data is contained

BrovMan12 wrote:

This seems not normal. I checked my storage. The macOS (latest 15.2) only takes 19.19GB.

It might be an additional 4.85 GB more if Apple Intelligence is enable

One called Macintosh HD - Data @ 22. 5GB and another called McIntosh HD- data @ 10.3 GB

This One to be removed >> MacIntosh HD- data @ 10.3 GB

Again and still in Disk Utilities

Maneuver to Macintosh HD-data ( Lower case d )

Click on " Macintosh HD-data "

In the lower left area on Disk Utilities

There is a Plus ( + ) and Minus ( - ) sign

Click the Minus ( - ) sign

That will remove the Macintosh HD-data Volume

In so doing, give the computer an additional 10.3 GB of space

This seems not normal. I checked my storage. The macOS (latest 15.2) only takes 19.19GB.

Let us both step back for a moment 😎

Let us review some of the replies

No, no double OS have been installed

Double User Accounts - Yes

This sometimes happens but is fixable

This is the 1 to Keep

I will post a second reply on how to remove the Other

So bare with me if you would