---
id: freeing-space.do-space-efficient-files-stay-small
url: https://storagestudio.us/faq/freeing-space/do-space-efficient-files-stay-small
category: "Freeing up space"
subcategory: "Stopping, undoing and apps in the way"
question: "Will virtual machine disks and disk images grow bigger when moved to the fast drive?"
alt_questions:
  - "Sparse files after moving"
  - "VM disk doubled in size after move"
  - "Disk image larger on external drive"
  - "Space-efficient files moving"
  - "Preallocated database moved"
short_answer: "No. Files that only use part of their apparent size, like some VM disks and disk images, keep that efficiency when Storage Studio moves a folder, as long as the drive's format supports it."
tags: ["sparse files", "virtual machines", "moving"]
related: ["https://storagestudio.us/faq/freeing-space/can-i-stop-a-clear-up-halfway", "https://storagestudio.us/faq/freeing-space/why-doesnt-stop-work-instantly"]
applies_to: "all"
last_reviewed: 2026-10-01
---

# Will virtual machine disks and disk images grow bigger when moved to the fast drive?

No — when Storage Studio moves a folder, files that only use part of their apparent size, such as some virtual machine disks, disk images and pre-allocated databases, keep that efficiency on your fast drive instead of ballooning to their full size.

That matters on the destination too: a file that shows 100 GB but uses 20 GB on your Mac should still use roughly 20 GB on the drive. If the fast drive is formatted in a way that can't store files like that, they may take more room there. For drive formats, see the [External drives FAQ](https://storagestudio.us/faq/external-drives/).