Q:

VmWare player - how to expand disk drive

I'm using VMWare on Win8 as host system and Ubuntu 16.04 as guest. I gave 10 GB to Ubuntu and then expanded it to 25 GB, but it doesn't rescan. Tried to use rescan-bus from other questions but it didn't work.

A:

Changing parameters in your hypervisor (virtualization program) won't be enough.
In the real physical world, you can't just come up with extra storage on an operating device out of nowhere.
The system needs to format it and index your new added hardware (create a file system).
This step is always done when you install a new OS.
And what you are trying to do is to create or expand the partition within the OS since it is already installed.
To do so, you'll need to use dedicated programs ('Partition Managers') such as GParted. If you have an active internet connection from your guest machine, you can simply use apt-get to install GParted. 

