---
id: external-drives.can-i-use-a-partition-of-my-internal-drive
url: https://storagestudio.us/faq/external-drives/can-i-use-a-partition-of-my-internal-drive
category: "External drives"
subcategory: "Choosing a drive"
question: "Can I use a second partition or volume on my Mac's internal drive?"
alt_questions:
  - "Can I move apps to another volume on the same SSD?"
  - "Why is my internal drive not suitable?"
  - "Use a partition as the fast drive"
  - "Can the fast drive be inside my Mac?"
  - "Storage Studio internal drive blocked"
  - "Will a second APFS volume on my Mac free space?"
short_answer: "No. Volumes on your internal drive share the same storage, so moving files between them frees nothing. Storage Studio marks internal volumes not suitable — the fast drive must be a separate, external drive."
tags: ["internal drive", "partition", "apfs volume", "not suitable"]
related: ["https://storagestudio.us/faq/external-drives/can-i-use-a-network-drive-or-nas", "https://storagestudio.us/faq/external-drives/what-kind-of-external-drive-should-i-use-with-storage-studio", "https://storagestudio.us/faq/external-drives/can-i-use-a-spinning-hard-drive-as-my-fast-drive"]
applies_to: "all"
last_reviewed: 2026-10-01
---

# Can I use a second partition or volume on my Mac's internal drive?

No. Any volume on your Mac's internal drive is marked **not suitable**, because moving files from one part of the same disk to another doesn't free any space — APFS volumes on one disk share the same pool of storage. The whole point of the fast drive is to put data on a *different* physical drive.

The drive list in **Choose Drive** shows your built-in disk with an internal icon so you can see it, but its verdict will always be not suitable, and Transfer Drive and Backup Drive never list it at all.