oracle-virtualbox
How to show the VirtualBox VM information.
          [code]root@server[#] VBoxManage showvminfo <vmname>[/code]

How to show the VM Harddrive info.
         [code] root@server[#] VBoxManage showhdinfo <filename>[/code]

How to list available ISOÔÇÖs
        [code] root@server[#] VBoxManage list dvds[/code]

How to list running VM.
          [code]root@server[#] VBoxManage list runningvms[/code]

How to list available VM.
         [code] root@server[#] VBoxManage list vms[/code]

How to list available VM Harddrives.
         [code] root@server[#] VBoxManage list hdds[/code]

How to Start VM
         use nohup command and & to run process in background, so VM continues to run after exiting console.
          [code]root@server[#] nohup VBoxHeadless --startvm <vmname> &[/code]

How to pause VM          
          [code]root@server[#] VBoxManage controlvm <vmname> pause[/code]

How to resume VM
         [code] root@server[#] VBoxManage controlvm <vmname> resume[/code]

How to reset VM
          [code]root@server[#] VBoxManage controlvm <vmname> reset[/code]

How to poweroff VM (hard poweroff eg. pull the plug)
          [code]root@server[#] VBoxManage controlvm <vmname> poweroff[/code]
How to send poweroff single to VM (tells VM OS to shutdown)
          [code] root@server[#] VBoxManage controlvm <vmname> acpipowerbutton[/code]

How to attach a DVD / CD to a running vm
          [code]root@server[#] VBoxManage controlvm <vmname> dvdattach <filename>[/code]

How to de-attach a DVD / CD from a running vm
          [code]root@server[#] VBoxManage controlvm <vmname> dvdattach none[/code]

How to find out the VM IP
          [code]root@server[#] VBoxManage guestproperty get <vmid>"/VirtualBox/GuestInfo/Net/0/V4/IP"[/code]