Can't shutdown

Need to move the Drobo to a new upgraded server but get message: The volume seems to be busy and prevents unmounting of the volume.

Do I just need to remove the shares from the old server in order to be able to shutdown?

Thanks.

What Drobo are you using?

Try quitting the application(s) that may be accessing it, or shutting down the PC(s).
Depending on the model, for direct attached ones, the power light would go into standby (orange), you could then safely shutdown (toggle power switch) and cut power.