Hi Eric,   "best" depends entirely on the I/O pattern expected.  Small random writes should use R10.  RAID50 is generally a good compromise on space and performance.  But does have the risk of a double faulted RAIDset bringing it down.   Another factor is the PS5000 is end of life.  No support, firmware or parts long term.  Using off the shelf drives add in uncertainty to the reliability of the array.   I would never use one of this for primary production data therefore.  To provide the best protection in this case, I would only use RAID6.   R10 would be next down, but can suffer and outage with two failed drives in the same mirror set.  Regards,   Don 
Good afternoon All I have studied the vagaries of the various raid options and was wondering if anyone has a practical insight using PS5000 SATA arrays?  Basically the array will provide backup drives to VMs so which Raid would be best for performance and capacity?  I was pondering Raid 50 or Raid 6 as the array is a distance from my office in a data centre to that there could be 2 failures before disaster...  Many thanks Eric 
PS5000 Sata array 16 drives - Raid for best performance and greatest capacity