Increasing storage to a existing disk attached to a VM

Increase the disk size allocated to the VM and make sure the datastore has enough space.  

echo 1 > /sys/block/<device-name>/device/rescan [Device name can be for example sdc]

fdisk /dev/sdc

p

d

n

p

default

w

partprobe /dev/sdc

pvresize /dev/sdc1 Validate it with pvs/vgs.