docs: update gofurther/resize
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title: Resize an existing virtual disk
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description:
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published: true
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date: 2026-05-08T09:03:28.700Z
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date: 2026-05-08T09:34:59.946Z
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tags:
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editor: markdown
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dateCreated: 2021-11-13T11:41:29.087Z
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---
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# Resize a disk
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# Resize a virtual disk
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## Background
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A virtual machine's disk may have to be resized, typically due to lack of space. This page explains how to do so.
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## Usage for Linux guests
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> In-place expansion is not supported. A new disk of the desired size has to be created.
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## Preparation
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### Shut down virtual machine
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> Please ensure that the virtual machine using the virtual disk to be resized is turned off
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{.is-warning}
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Let's assume that you wish to increase the size of the virtual machine called *guest*.
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- List virtual machines running on your host
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```
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# virsh list --all
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Id Name State
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----------------------------------------------------
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1 guest running
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```
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- Shutdown the *guest* virtual machine
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```
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# virsh shutdown guest
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```
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- Ensure that the virtual machine is fully shut off
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```
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# virsh list --all
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Id Name State
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----------------------------------------------------
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1 guest shut off
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```
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It is now safe to proceed to the next step
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### Backup existing disk
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It is advisable to make a backup first.
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- Navigate to the correct directory
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```
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# cd /var/lib/libvirt/images
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```
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- Make a copy of the virtual disk image
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```
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# cp guest.img backup_guest.img
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```
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## Linux guests
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> In-place expansion is not supported. A new disk of the desired size has to be created, and then swap with the former disk.
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{.is-info}
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* Navigate to the location that contains the existing image
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- Navigate to the location that contains the existing image
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```
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cd /var/lib/libvirt/images
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# cd /var/lib/libvirt/images
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```
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* Create a new blank disk image of the desired size
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Use the following command to create a disk of 20 GB called `guest_20G.img`.
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- Create a new blank 20 GB disk called `guest_20G.img`
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```
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qemu-img create -f raw guest_20G.img 20G
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# qemu-img create -f raw guest_20G.img 20G
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```
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* Identify the filesystem layout of the existing disk `guest.img`
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- Identify the filesystem layout of the existing disk `guest.img`, which is ext4-based
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```
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# virt-filesystems -a -l -h guest.img
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# virt-filesystems -a guest.img -l -h
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Name Type VFS Label Size Parent
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/dev/vda1 filesystem vfat EFI 133935104 -
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/dev/vda2 filesystem ext4 boot 366869504 -
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/dev/vda3 filesystem ext4 root 9933475840 -
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/dev/vda1 filesystem vfat EFI 1.3G -
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/dev/vda2 filesystem ext4 boot 3.6G -
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/dev/vda3 filesystem ext4 root 10G -
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```
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One can tell that the root partition is located under `/dev/vda3`. This is the one that will need to be expanded.
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- Another output for a btrfs-based filesystem
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* Copy the formet old data to the new disk and expand the root partition of the said disk
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```
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# virt-filesystems -a bazzite-desktop.img -l -h
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Name Type VFS Label Size Parent
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/dev/sda1 filesystem vfat - 599M -
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/dev/sda2 filesystem ext4 bazzite_xboot 1.9G -
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/dev/sda3 filesystem btrfs bazzite 37G -
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btrfsvol:/dev/sda3/root filesystem btrfs bazzite - -
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btrfsvol:/dev/sda3/home filesystem btrfs bazzite - -
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btrfsvol:/dev/sda3/var filesystem btrfs bazzite - -
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```
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Thanks to the label on the ext4-based based image, one can tell that the root partition is `/dev/vda3`. This is the one that will need to be expanded. For the btrfs example, the root partition `/dev/sda3`as shown by `btrfsvol:/dev/sda3/root`
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* Copy the former old data to the new disk and expand the root partition of the said disk
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> This command is capable of expanding different kinds of filesystems, including `ext4` and `btrfs`
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{.is-info}
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The command takes the new empty disk as last argument.
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> Data could be erased if you mix argument!
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{.is-warning}
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```
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# virt-resize --expand /dev/vda3 guest.img guest_20G.img
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```
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* Review the changes
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* Review changes
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```
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[ 0.0] Examining guest_20G.img
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