How to expand storage

I’m using the librenms VM image provided from the website with the default 10GB and it’s running out of storage soon. I need to expand the storage but should I increase the capacity of the existing 10GB disk to 20GB or add another 10GB disk?

btw, how do I tell if LVM is used?

Task completed by adding new disk:

fdisk /dev/sdb
n (create new partition)
p (primary partition)
1 (partition 1)
enter twice to accept default sector values
t (change type)
8e (type to LVM)
w (write changes)

pvcreate /dev/sdb
vgextend centos /dev/sdb
lvextend -L +20G /dev/mapper/centos-root
xfs_growfs /dev/mapper/centos-root


btw, after adding a new disk to expand the storage in LibreNMS, I got this error.

This mean after the task is completed, I still have to execute this:

sudo chmod 774 ucd_diskio-sdb.rrd
sudo chmod 774 ucd_diskio-fd0.rrd