Install OS on memory card?
 

I just had an idea on how to maximize space on a server i'm looking to build. I'm planning on purchasing a Precision T7400 and put a memory card reader in it, and i'm wondering; would i be able to install the operating system onto a compactflash memory card which will be plugged in at all times? Instead of installing a dedicated hard drive, that way I can leave 4 slots up for data drives in the tower. Would this be possible?

If the issue is SATA/SAS headers, can you just add a PCI/PCIe card? Or are you worried about places to mount 4 3.5" HDDs? What are you planning to use this server for?

The main issue of mine is not more of the space needed for the drives inside, because i feel i could probably fit 2 more drives in the optical drive bays. It's more of trying to get past how much space the motherboard can see, or if i can't, utilize the amount of installed hard drives effectively. Supposedly this line of Precisions can only go up to 5TB, which i might need to install more down the road.