I had reason to copy everything on my Pegasus2 R4 to another harddrive. I checked with Get Info (Mac OS) to see how much was on the Pegasus. Fine, enough room on the other drive. But when it had copied that number of GBs, it kept going. And going. 
Anyway, later when I had reconfigured the Pegasus to a level 5 array (yeah, I know that's the default but I'd foolishly changed that and now wanted to change it back), I could see in Promise Utility that I had three physical disks with 2TB each, so 6TB of space, right? But Get Info says it's just 4TB. So, I'm guessing that Get Info doesn't know how much space there really is. Right?