I bit the bullet and forked out for the new 2011 Mini Server to setup as a media server at home. I figured I would use an external drive to store the media, and a redundant OS drive would be more reasonable that way if the primary drive goes, the media server still works for the wife until I can replace the drive. I found instructions for configuring a RAID1 on the system and started the process. I burned a Lion DVD from my 2010 MBP and used an external DVD drive to try to boot the system. Alas, it gave me a circle with a slash. I made a USB drive version that booted fine on the MBP but the Mini still gave the circle of fail. Then I read about the Mini and MBA having special versions of Lion that somehow prevented booting from an external device. I figured I could boot off the MBP in target disk mode and....SUCCESS! I went through the steps and setup the RAID1 using diskutil commands and waited until the RAID rebuilt. I checked the status several hours later and the RAID was all good. I powered off both systems, removed the Firewire cable and powered up the Mini and watched in horror as it gave me the dreaded circle of fail. Try as I might, I couldn't get it to boot from the internal drives. I even went so far as to say screw it and start fresh. I booted into the network recovery option, entered my WiFi settings and watched in even MORE horror as I got the -2100F error. I tried several times and even went so far as to plug in an ethernet cable to my Airport. At this point, I was about to box it up and ship it back and go buy an Apple TV to load up XMBC. I decided to go crazy and try booting off the MBP in TD mode again. I went into disk utility and broke the mirror between the two drives, then simply shut down and restarted. The Mini booted just fine and I was back in business with my two individual drives. Now that that story is over.... Who else has gotten this -2100F error? No matter what I did I couldn't restore the system, and I'm nervous that if I need to restore in the future I'll be screwed. Also, is there any reliable way to create a mirror using the two internal drives? I went with the server option mostly for this ability, and it looks like it's a no-go. Last, if I were to make an image of my server's primary drive using Carbon Copy Cloner, would I be able to boot off the image and recover my computer without having to attempt the network recovery mode? What I want to try is making the CCC image and booting from the external. I suspect the existing RAID1 configuration was the -2100F problem, basically a 'no disk found' kind of error. Now that there isn't a RAID in place I want to see if the network recovery works for my own piece of mind. However, I don't want to lose the hours of time I spent configuring software and settings to make the system run exactly how I want. I know it was a rambling post, but I spent a good 20 hours between the configuration, RAID-ing, fixing and testing and I don't want to have to go through it again.