Inconsistent state of attached disks, cannot close medium

[Kamil Jońca]

1. I have running VM

2. Then I attach disk, I want to be sure that it is hotpluggable

   VBoxManage storageattach itr  --storagectl SATA --port 2 --type hdd --hotpluggable on --medium /media/usb/1/kjonca/vdi/wsus.vdi
   

   got error:

   VBoxManage: error: The machine is not mutable (state is Running)
   VBoxManage: error: Details: code VBOX_E_INVALID_VM_STATE (0x80bb0002), component SessionMachine, interface IMachine, callee nsISupports
   VBoxManage: error: Context: "SetHotPluggableForDevice(Bstr(pszCtl).raw(), port, device, TRUE)" at line 881 of file VBoxManageStorageController.cpp
   

3. I cannot deregister disk:

   VBoxManage storageattach itr  --storagectl SATA --port 2 --medium none ; VBoxManage closemedium /media/usb/1/kjonca/vdi/wsus.vdi
   VBoxManage: error: Medium '/media/usb/1/kjonca/vdi/wsus.vdi' is locked for writing by another task
   VBoxManage: error: Details: code VBOX_E_INVALID_OBJECT_STATE (0x80bb0007), component MediumWrap, interface IMedium, callee nsISupports
   VBoxManage: error: Context: "Close()" at line 1554 of file VBoxManageDisk.cpp
   

The only way to resolve it is restarting virtualbox.