it's possible. Essentially you would create two CIFS servers on VNX.  When i perform this kind of migrations i first create a CIFS server with _new in the name, join it to active directory and then begin copying data from the windows server using "emcopy" utility. This utility is similar to robocopy but much faster, it should be located on one of your VNX application CDs. On the final day of cutover, you disconnect users from the windows server, run final emcopy which should only copy the changes after last emcopy. When that's done you unjoin CIFS server from active directory, you unjoin physical server from active directory and shut it down. You create IP interface on VNX that is the IP address of physical server, you rename the CIFS server to match the name of the physical box and give it the new IP address as well.  You also want to look at utility lgdup and sharedup that will allow you to migrate shares and share permissions as well as any local groups you have.

Thanks this is exactly what I was looking for.

I simply wanted to make a quick comment.  Even though the utility is on the CD that comes shipped with the hardware; I'd recommend always looking for it on PowerLink via the following breadcrumb trail:

Home > Support > Product and Diagnostic Tools > Celerra Tools > Windows Migration Tools > EMCOPY

The latest is emcopy v4.12 which was released only a couple of weeks ago: August 26, 2011 so it is likely the copy on the CD is behind a revision (at least).

Good tip , thanks