I'm assuming that the volume is not the system drive and that you want to erase the whole of it.
This can be done in one go if you use a 6.1/6.2 (beta standard) build (2284 is the latest posted build at the time of writing). If you want to use the latest stable build (6.0.8.2273), you format the volume (a quick format, if available, is fine), then run Erase Free Space.
Will it work? I've never dealt with EMC gear (a bit out of my league) and the EMC website isn't exactly generous with nuts and bolts technical information. If the volume is some sort of RAID array, and Windows can see it as a conventional drive, erasing will probably work; what erasing does is fill the drive with nonsense files, then delete them, then clear the file table.
There is no facility to pause an erase, I am afraid. It will be a long job; make sure you use the default single pass method for free space erasing!
David
