Please help me to understand this question.
Between NIS, NFS, and DFS, the need for coordinated sharing of remote files seems to be well established. However, the principles and mechanisms are the subject of a long-standing debate. Contentious concerns-such as consistency, replication, performance, and security-have stymied a universal solution. What do you see as the principal issue, and where do you stand on it? Justify the tradeoffs you believe are appropriate.