I am purchasing two IBM rack servers for a group. One will sit onsite and the other offsite as a backup. Onsite replicates to offsite using Legato Replistor over a WAN link. However, in addition to the failover, I also want to have local redundancy and fault tolerance. The IBM server is an xSeries 345 2.8Ghz which offers 6 hotswap drives with integrated RAID 1. I know the server will be heavily written to and read from as there will be a database of documents stored on it that is expected to grow up to 200GB or more. I’m stuck as how to implement RAID on such a system. Should I mirror the OS on two drives and RAID 5 the last 4 slots? What space considerations are needed? What performance hits will occur if I used Windows 2000 Server RAID as opposed to hardware RAID?