At least one I am aware of: 656 McBryde. 

More available for the undergrads (I guess you can use them too), see below, 
+ some useful names:  

--------------------------------------------
From vrivelli@cs.vt.edu Tue Sep 30 22:54:24 2003
Date: Fri, 22 Aug 2003 16:25:55 -0400 (EDT)
From: Vincent Rivellino <vrivelli@cs.vt.edu>
To: Deborah Tatar <tatar@cs.vt.edu>, Alexey Onufriev <onufriev@cs.vt.edu>,
     T. M. Murali <murali@cs.vt.edu>, Adrian Sandu <asandu@cs.vt.edu>
Cc: techstaff@cs.vt.edu
Subject: Re: new CS authentication system (fwd)
                                                                                
Some more info for the new faculty about the undergrad labs ...

McBryde 116, 118, & 124 houses the computer lab for undergraduate
students.
                                                                                
McB 116: is an open lab to all undergratuate students taking CS classes,
  has a number of Windows and Linux systems, hours of operation are
  10am-midnight Mon-Thu, 10am-5pm Fri, 4pm-midnight Sun (however, it will
  be closed until Sept 1)
                                                                                
McB 118: has ~30 Windows machines, used for class instruction, is an
  "open" lab (as 116 is) when there are no classes in it

McB 124: has ~30 Linux machines, is not an "open" lab, used for class
  instruction
                                                                                
Gay Meredith (egm@cs.vt.edu) is the manager for these labs.  Chris Arnold
(carnold@cs.vt.edu) manages the administration of the Windows systems (as
well as the servers).  Phil Meents (pmeents@cs.vt.edu) is a part-time
student worker who manages the administration of the Linux systems.  I
help out with some of the Linux administration.