mrpeja ,
I'm running a mill on Linux with an Ajax control. No hard drive. the machine runs off a flash card with Linux, and have NO problems.
The benefits of running off a flash card, means no moving parts , not effected by any vibrations, as in machining enviorment. Has been running for 4 years now. The cost was a little over 4,000 for the install, just for the electronics.
But Mach is a lot cheaper , and will do more than the Ajax setup.
Ed