Two Macintosh HDs in Disk Utility: what the Data volume is, and which one is yours
Since macOS Catalina your disk is split into a sealed system volume and a Data volume with your files. Why there are two, and which to check for space.
730 guides
Mac storage, explained.
What fills your disk, where it hides, and what is safe to remove. Every guide gives you a way to check it on your own Mac.
A Recovered Files folder appeared in your Trash: what it is and whether to keep it
After a restart or crash, macOS can put a Recovered Files folder in the Trash. What is inside, how to check it, and when it is safe to empty.
The /cores folder can hold gigabytes of crash dumps nobody asked for
Core dumps are full memory snapshots written when a program crashes, and each can be gigabytes. Where they live, why they appear, and how to remove them.
The Biome folder in your Library: what macOS records there and whether it can be cleared
~/Library/Biome holds on-device activity data that powers suggestions and Screen Time. Usually small, sometimes gigabytes. How to check it and what is safe.
Starting in Safe Mode clears some caches. Here is how much space that really frees
Safe Mode deletes certain system caches as it starts, which is why people suggest it for a full disk. What it clears, how to measure the difference, and limits.
Does FileVault take up disk space? No, and here is how to check
FileVault encrypts your disk without making files larger or reserving space. What it costs, what it does not, and how to see whether it is on.
Alias, copy, duplicate or symlink: which ones actually use more space on a Mac
An alias is tiny, a copy on the same disk may be free, and a copy to another drive is full size. What each one costs and how to check which you have.
Your system has run out of application memory: on a full disk, the fix is free space
This macOS warning is about memory, but on a nearly full disk the cause is often no room for swap. How to tell which you have, and what to do next.
No space left on device in Terminal: find what filled the disk and free enough to continue
The error means a write failed because a disk or volume is full. How to tell which one, free enough space in minutes, and stop it recurring.
Optimize Mac Storage is on, but the Photos library is still huge: what it actually does
Optimize Mac Storage only shrinks your library when the Mac is short of space, and only for photos safely in iCloud. How to check it is working.
Turning off iCloud Desktop and Documents: where your files go, and the copy you might leave
When you turn it off, your files stay in iCloud Drive and your Mac gets empty folders. How to bring them back without losing any, or keeping two copies.
Every Live Photo is a photo and a short video, and your Mac keeps both
Live Photos store a three second video beside each picture, which can roughly double a library. How to see the cost, and turn them off going forward.