When you say “replication” do you mean SnapMirror? If yes, then
1. Yes in general. There are some limitations when using VSM (cannot replicate to lower Data ONTAP version, cannot replicate between 32 and 64 bit aggregates)
2. Yes, sync and async SnapMirror are supported. I am not sure I understand the third one. Async SnapMirror works by creating snapshot on source and transferring delta between it and previous snapshot. May be is answers your question.
Hmm … yes, there are storage systems that can do async replication without explicitly or implicitly creating snapshots. If this is what you mean, then async SnapMirror is snapshot replication ☺
