I have a department server running Win Std Srv 2003 that serves 35 users. It is my domain controller, file server and also spools a plotter and printer. Its specs are as follows: SuperMicro Intel SE7500CW2,Dual Xeon 2.8 mhz with 1gig of ram, onboard LSI Logic 53c101-66 controller with additional Adaptec AHA 2940U pci SCSI controller. Seagate ST3336607LW HD, Seagate 6340 tape drive and CD-Rom. It has been in service about one year and I would like to add a matching Seagate SCSI drive to add a bit of redundancy. I have looked at KB Q302969 which talkes about adding a second drive but don't know if this is the best way to go. My current HD is formatted 4gig/OS and 30.18/Data. If I use the softare version of RAID 1 will it mirror both OS and Data? Would you go Software or Hardware RAID?