This is my journey in building my own at home private cloud
It has no high availability from the processing node perspective as there is no fail-over/backup processing hardware to make this a highly available cluster. There is a solution to this as described in http://www.linuxjournal.com/content/two-pi-r?page=0,1 if you like the challenge. I might do that at another time.
It only has disk high availability from 3 x 3TB USB 3.0 external disks turning this build into a nice NAS for my PCs, VMs, and laptops. We’ll see how slowly it crawls. It actually has decent performance for daily routines. Large file size & number copies will make it crawl. I just do that overnight (copied my iTunes library over).
Yes, I’m a digital pack-rat .