The guide used in the video can be found here:
After adding extra space to your server, the space will need to be allocated. All Virtual, Cloud and CloudNX servers are deployed using a Logical Volume. This does not automatically extend to use extra drive space added. This video will explain the steps needed to be taken to utilise the extra space.
Publisher: Fasthosts Internet
More: Watch all Fasthosts videos
You can watch this video also at the source.