Proxmox Ubuntu Disk Resize

If you have installed Ubuntu on Proxmox there is a chance at somepoint that your /dev/mapper partition will become full.

To expand it. Log into Proxmox, Resize the LVM by adding xG.

SSH onto your Ubuntu VM

df -h (shows the issue)

/dev/mapper/ubuntu--vg-ubuntu--lv                                            19G   13G  4.8G  74% /

fdisk -l

sudo /sbin/lvresize -l +100%FREE /dev/mapper/ubuntu--vg-ubuntu--lv

sudo /sbin/resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv

Done

EDIT: I ran into some issues when the LVM part is full and it cant write any changes. Try the Following

sudo apt-get clean

sudo pvresize /dev/sda3

sudo lvextend /dev/mapper/ubuntu--vg-ubuntu--lv -l+100%FREE

reboot