depending on how your backplane is configured without causing any lan traffic to be impacted. Depends on whether the backplane can be isolated. On the unisphere gear (now jupiter I think) we could completely isolate the bandwidth on the backplane by allocating max thruput. That was in the late 1990's. Once that value was hit that's all it could use. If your gear can do that, it simplifies matters.
Also note your edge gear on a shared box should be wired to different san and switches than your lan gear.
Also note your edge gear on a shared box should be wired to different san and switches than your lan gear.