Resizing no parted command fdisk not working as expected

I am using UCS 4.4 with owncloud.
I resized the partition in virtual box. I then booted to a Linux installer and resized the partition using gparted. Rebooted and same size problem.
lsblk shows the extra unassigned space.
Trying to follow other threads there is no parted command.
and doing the process listed
resize2fs /dev/sda3 gives errors. resize2fs /dev/sda5 device or resource busy while trying to open /dev/sda5
Any help please.

You should follow this guide:

Maybe this video might help you: