Looking for recommendations on what RAID setup to use on a T610, PERC6i controller. We typically use RAID1-OS and RAID5-Data in our enviornment and heard that RAID6 will give us better redundancy at a cost of performance. Our current PE2900 servers setup with Win2003 host and VMware Server with a RAID1-OS and RAID5-Data, (virtual disks are located on the Data partition) tend to give us VM performance issues as it is. We currently have local backup to disk in addition to remote backups and would like to know if the performance hit is worth the added redundancy.

Depends. What type of IO ? Reads vs Writes / size of IO requests. You'll give up a little in RAID-6 - great performance paper on the PERC here that should help --> http://www.delltechcenter.com/page/PERC+6+Performance+Analysis+Report

Best way to improve disk performance is to add spindles. How many are currently in your RAID5-Data right now ? You'll also need to be conscience of how may VMs you are putting per LUN and what they may be doing to cause spindle contention.