I am currently initializing a 1TB Volume to our DR site over a 100 MB link. I am anticipating it will take over 40 hrs. The dilemma is that the volume on the source filer is snapped once a day via snapdrive by a batch file, run by a scheduled task on the server, at 0500 hrs every morning.
Snapshot deletion does not take the volume offline so Peter's answer is still correct. It may be an idea to pause snaps whilst the volume is initializing to prevent them growing too large while data change rate is increased.