My situation

/media/nss/test - primary storage-->iscsi storage 100GB

/media/nss/shadow/test -shadow storage for test -->san storage 50GB

I need to create a policy where by when user access and modified the file from primary storage it wll go to the shadow storage. Is this possible to do it? I had perform a lot testing and it only can run from shadow to primary when the file is modified or access.

Please advise on that.