Grow Windows 8.1 VM NTFS volume

Prerequisites (usually met in a VM)

• Windows partition to increase is the last one
• VM disk is saved on a raw file

Assumption (change to match your environment)

• New raw file size is 40 GB

Implementation

• stop VM
• sparsely increase raw file size (bs*seek ~ new size)

dd if=/dev/zero of=/path/to/your/rawfile bs=1M count=1 seek=40960

• start VM
• login to windows VM
• start Computer/Management/Disk Manager
• right click on last partition before the new space
• select increase volume and allow it to use all space
• done :)