Maintenance and security

Manage storage and updates

Find what consumes disk space and install operating-system updates without deleting unknown system data by hand.

8 minute lesson

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Open System Settings → General → Storage to see broad categories and recommendations. Treat the category sizes as a starting point, not a precise map of files you can safely delete.

Begin with data you recognize:

  • old downloads and disk images
  • applications you no longer use
  • videos or archives you created
  • old device backups
  • build artifacts that your tools can recreate

Move items to the Trash first. Confirm your applications and projects still work before emptying it.

Do not delete unknown Library data blindly

~/Library contains application settings, containers, caches, mail, and other account data. /Library contains shared resources.

Some caches are disposable, but deleting a random folder can sign you out, remove offline data, or break an application. Use the application’s cleanup controls or current vendor guidance when available.

A cleanup tool also needs review. Full Disk Access gives it broad reach; a large “system data” number does not justify deleting files you cannot identify.

Prepare for macOS updates

Install security updates promptly, but treat a major macOS version upgrade as a project:

  1. Complete and verify a backup.
  2. Check free space and power.
  3. Confirm critical applications, drivers, package managers, and development tools support the new version.
  4. Record any tool versions you may need to reinstall.
  5. Choose a time when recovery will not interrupt important work.

After updating, verify login, networking, backups, command-line tools, and the projects you depend on.

If storage remains unexpectedly full, use Finder or a trusted disk-usage tool to locate real files. Do not bypass macOS protections to delete system-managed data.

Try this: identify 1 GB of storage you could recover from files you recognize, but stop before deleting it. Write the verification you would perform afterward.

Lesson completed

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