Guest fails to recognize installation media (USB)

[kynnjo]

I have a live Debian installation medium on a USB stick.

I have used this very same USB stick to install Debian on other VirtualBox'es (running on Debian hosts), as recently as a few hours ago.

In all other installations, the USB stick has been readily recognized by the VirtualBox Manager. In fact, up to now it has always been so uneventful that I don't recall the details.

But now I'm trying to do what I thought was an identical installation on a different Debian host, and this time the USB is simply not recognized by the VirtualBox Manager.

If I manually enter the device for the USB stick (I've tried both /dev/sdd1 and /dev/sdd), the VB Manager complains with either

Failed to open the optical disk file /dev/sdd.
Permission problem accessing the file for the medium '/dev/sdd' (VERR_ACCESS_DENIED).

Result Code:
VBOX_E_FILE_ERROR (0x80BB0004)
Component:
Medium
Interface:
IMedium {05f2bbb6-a3a6-4fb9-9b49-6d0dda7142ac}
Callee:
IVirtualBox {fafa4e17-1ee2-4905-a10e-fe7c18bf5554}
Callee RC:
VBOX_E_OBJECT_NOT_FOUND (0x80BB0001)

or

Could not get the storage format of the medium '/dev/sdd' (VERR_NOT_SUPPORTED).

Result Code:
VBOX_E_IPRT_ERROR (0x80BB0005)
Component:
Medium
Interface:
IMedium {05f2bbb6-a3a6-4fb9-9b49-6d0dda7142ac}
Callee:
IVirtualBox {fafa4e17-1ee2-4905-a10e-fe7c18bf5554}
Callee RC:
VBOX_E_OBJECT_NOT_FOUND (0x80BB0001)

How can I get the VBM to recognize this installation medium?

Thanks in advance!

kj

[socratis]

How exactly are you trying to use the USB stick to install Debian? Because VBox doesn't support booting from a USB.