Answering my own question:
http://social.technet.microsoft.com/...b-3777899cf7de
The technique listed in the above post seems to work.
"Simon Thomson" <> wrote in message
news:O2$...
> We run SBS 2008 virtualised under VMware ESXi which like most hypervisors
> does not support USB passthrough to the guest OS.
> This limitation creates a complication with SBS backup which we have
> resolved by implementing a USB over IP device to present a USB HDD to SBS
> as a backup target. Unfortunatley the software that runs the device does
> not install as a service so if the Admin account is logged off the backup
> HDD is disconnected, not an ideal situation.
>
> The old "path\INSTSRV.EXE My Service path\SRVANY.EXE" does not seem to be
> supported under Server 2008, does anyone know of the 2008 equivalent or a
> way to get the old method to work on SBS 2008?
>
> Cheers,
> Simon.
>