Increase the disksize of a VM (on Unraid)

Following these steps should suffice.

• First of all, shutdown the VM

• Get some info about the image (I use a raw disk usually)

  $ qemu-img info -f raw vdisk1.img
  

• Resize the image (add 40 gigabytes)

  $ qemu-img resize -f raw vdisk1.img +40G
  

• Start the VM and log into a terminal on the VM

• Resize the filesystems partition up to 100%

  $ sudo parted /dev/vda resizepart 2 100%
  

• Extend the filesystem on the resized partition (I use btrfs here)

  $ sudo btrfs filesystem resize max /
  

  Additional information for other filesystems
  For the classic ext4 filesystem it should be (not tested yet):

  $ sudo resize2fs /dev/vda2
  

• Reboot the VM

That’s it. Following a few sources:

• https://gist.github.com/zakkak/ab08672ff9d137bbc0b2d0792a73b7d2
• https://linuxiac.com/how-to-resize-extend-kvm-virtual-disk-size/
• https://unix.stackexchange.com/questions/373063/auto-expand-last-partition-to-use-all-unallocated-space-using-parted-in-batch-m