---
id: mac-storage-basics.what-are-the-preboot-recovery-and-vm-volumes
url: https://storagestudio.us/faq/mac-storage-basics/what-are-the-preboot-recovery-and-vm-volumes
category: "Mac storage basics"
subcategory: "Disks, APFS and formats"
question: "What are the Preboot, Recovery, VM and Update volumes in Disk Utility?"
alt_questions:
  - "preboot volume mac"
  - "vm volume disk utility"
  - "recovery volume size"
  - "hidden apfs volumes"
  - "what is update volume mac"
  - "show all volumes disk utility"
short_answer: "They're small system volumes macOS manages: Preboot for startup, Recovery for repairs, VM for swap and sleep files, Update for installs. Leave them alone."
tags: ["apfs", "volumes", "disk utility"]
related: ["https://storagestudio.us/faq/mac-storage-basics/what-is-an-apfs-container-and-volume", "https://storagestudio.us/faq/mac-storage-basics/can-i-delete-the-recovery-partition"]
applies_to: "all"
last_reviewed: 2026-10-01
---

# What are the Preboot, Recovery, VM and Update volumes in Disk Utility?

They're small system volumes that live in the same APFS container as your Macintosh HD:

- **Preboot** — files needed to start up, including for FileVault.
- **Recovery** — macOS Recovery, used for repairs and reinstalling.
- **VM** — swap and sleep files.
- **Update** — used while installing macOS updates.

macOS manages them; don't delete or reformat them. They share the container's free space with your data, which is why the numbers in Disk Utility don't add up to one simple figure. Background: [APFS containers and volumes](https://storagestudio.us/faq/mac-storage-basics/what-is-an-apfs-container-and-volume).