Insert disk
Identify new disk
lsblk
Partition new disk (using /dev/sdb as example)
gdisk /dev/sdb
# print current partition table to confirm
p
# create new partition
n
# use full disk
[ENTER]
[ENTER]
# type 8e00 for LVM if using LVM or LVM-Thin on Proxmox
8e00
# print partition table to check
p
# write changes to disk
w
Scan all disks for lvm capabilities
lvmdiskscan
Create new Physical Volume on the previously created LVM partition
pvcreate /dev/sdb1
Extend the current Proxmox LVM group (pve) to include the new Physical Volume
vgextend pve /dev/sdb1
Confirm the new (hopefully larger) size
vgdisplay
Confirm the name structure of the data volume you wish to extend
lvscan
Resize the existing Logical Volume (data) to use all free space available on the now larger Volume Group
lvresize -l +100%FREE pve/data
Confirm the new disk and LVM partition layout
vgdisplay
lvdisplay
Reload Proxmox Web GUI to confirm the changes (Datacentre > pve > local-lvm > Summary)