Resize VM Partition

So you just changed the disk size of a virtual machine on proxmox, but you don’t see the updated size inside the VM when you run lsblk or df -h.

First, rescan your disk:

echo 1 | sudo tee /sys/class/block/sda/device/rescan

This is your situation:

$ lsblk -a
NAME                MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
sda                   8:0    0   248G  0 disk
├─sda1                8:1    0     2M  0 part
├─sda2                8:2    0   500M  0 part /boot/efi
├─sda3                8:3    0     2G  0 part /boot
└─sda4                8:4    0 245.6G  0 part            # HERE!!!
  └─systemVG-LVRoot 252:0    0 117.6G  0 lvm  /
...

$ df -h
Filesystem                   Size  Used Avail Use% Mounted on
/dev/mapper/systemVG-LVRoot  118G   13G  106G  11% /
...

To expand sda4 to the full size, run this:

sudo pvresize /dev/sda4
sudo lvextend -r -l +100%FREE /dev/systemVG/LVRoot