vmware gives wrong feedback “unable to open xxx.vmdk …” in case it it not able to access the phyical harddrive.

environment:

• ubuntu 8.04
• vmware workstation 6.xx
• using physical installation of a windows partition on /dev/sda (in this case)

Here the problem could solved easily:
just add the group “disk” to the user who is starting vmware:

• open control panel / user management
• switch to administrator mode
• select tab groups and add “disk” to the user