We currently use MS 2000 Clustering Service for 2 UNC shares that absolutely need to be up 24X7. The Clustering Service is attached to a 140Gb NetApp LUN. We either need to buy another NetApp OR find another way to make a UNC share rock solid and up 24X7. The UNC share will have millions files and will grow to 500Gb or larger and will have heavy access. It is for a third party mail server which is clustered, load balanced, and keeps it's mail in that LUN. Will MSS2003 (Microsoft Storeage Server) work for this? Can I cluster the data using VSS to another machine and have some sort of MS clustering or failover policy in case the MSS2003 server crashes? What are options for having a UNC share up 99.999%?