There is some cases when you need to grow/enlarge a partition on a virtual disk (usually represented as /dev/vdX), here is how to do it rebooting once (yes, i would be better sysadmin if no reboot was needed )
We use this /dev/vda setup in the example:
/dev/vda --/dev/vda1 20GB ext4 --/dev/vda2 2GB swap
# in my case, i had a non-used swap partition at the end of /dev/vda, # so i swap it off and delete it using fdisk swapoff -a fdisk /dev/vda > d > 2 > w # i announce the changes to the OS partprobe /dev/vda # i grow the first partition (defaults to the max size of the physical disk) growpart /dev/vda 1 # it MIGHT need reboot, but maybe not shutdown -r now # if you HAVE AN LVM ext4 you must pvs # PFree must show new space pvresize /dev/vda1 vgs # same as pvs lvs # you must see new available space here too lvextend -l +100%FREE /dev/thelvm-vg/mapper-lv # resize2fs on the partition if NOT LVM resize2fs /dev/vda1