Migrate VM from VMWare Workstation v 7.xx to VMWare ESXi v 4.xx
1. Install and configure VMWare ESXi v4.xx using instructions from official site. The only one thing, I have to change is to allow CPU Virtualization feature in BIOS.
2. Enable local and / or remote administration shell using instructions here: http://itknowledgeexchange.techtarget.com/it-consultant/enabling-ssh-on-a-vmware-esxi-server/
3. Copy your VMs files (*.vmdk)
For weird reason I was not been able to mount additional SATA drive with old virtual machines. The only way to copy files was to use scp and copy files over network.
4. Convert old VMs using vmkfstools utility.
vmkfstools -i "old_virtual_machine_disk.vmdk" -d thin "new_virtual_machine_disk.vmdk"
5. Create new VM in advanced mode and specify existing drive to newly converted disk.