Create a Logical Volume in Proxmox for shared data between LXCs

proxmox-create-shared-data.sh

# Create a LV-Thin volume named 'shared-data'
# Not visible in Proxmox gui
# Visibel with `lvs`
lvcreate -V 256G -n shared-data pve/data

# Create ext4 fs in the volume
mkfs.ext4 /dev/pve/shared-data

# Create directory mount point
mkdir /shared-data

# Add to fstab, and mount without reboot
echo '/dev/pve/shared-data /shared-data ext4 defaults 0 2' >> /etc/fstab
systemctl daemon-reload
mount -a