>I'm puzzled. We have a storage pool with co-location set on, yet after =
>querying the volume usage table it suggest more than one node is stored on =
>a given volume. Anyone hazard a guess as to why?

Consult the manual on collocation rules.  A volumes shortage can cause it.
Maybe you turned collocation on some time after volumes started holding data.
You can query contents to get more perspective on when the data got there
and under what circumstances per your Activity Logs.
   Richard Sims, BU