Proxmox - Resize Debian VM Disk

In Proxmox Virtual Environment, resizing a Debian virtual machine disk involves a few steps. Follow the instructions below.

1. Proxmox host

Open a terminal or SSH into your Proxmox VE host. Check the current disk size for the VM:

qm config VM_ID
# Example result: scsi0: local-zfs:vm-108-disk-0,size=65G

Resize the VM disk (replace VM_ID with your VM ID and SIZE with the amount to add, e.g. +15G):

qm resize VM_ID scsi0 +SIZE
# Example: qm resize 108 scsi0 +15G

2. Debian VM

SSH into your Debian VM:

Confirm the new disk size:

lsblk
sudo dmesg | grep sda

View the current partition table:

sudo sfdisk -uS -d /dev/sda

Resize the partition (adjust for your layout; this example assumes one partition):

echo "2048,,83,-" | sudo sfdisk --force -uS /dev/sda
sudo resize2fs /dev/sda1

Reboot the VM:

sudo reboot

After these steps, the Debian VM should have a resized disk. Back up important data before making changes. Optional: create a snapshot first, e.g. qm snapshot 108 test-resize.