Bare Metal Meaning

(computing) Physical hardware, as opposed to virtualised.

Example: Used other than as an idiom: see bare,‎ metal.
1987, "The Real Programmer's Handbook", U-M Computing News Volume 2, UM Libraries, page 7
  Real programmers don't write applications programs; they program right down to the bare metal. Applications programming is for wimps who can't do systems programming.
1997, Embedded Systems Programming, Miller Freeman Publications, page 118
  After all, this isn't PC Week, or another magazine that primarily covers the happenings of the PC world. This is Embedded Systems Programming, where we often program right down to the bare metal like Real Programmers, unlike those sissy PC guys (insert the sound of a hairy chest being thumped here).
2009, Peter Seibel, Coders at Work: Reflections on the Craft of Programming, Apress (ISBN 9781430219491)
  Which has its pluses and minuses—it's really hard to write device drivers for bare metal in a completely type-safe language just because the levels of abstraction are wrong for talking to the bare metal.
2012, John Ray, William Ray, Sams Teach Yourself Xcode 4 in 24 Hours, Sams Publishing (ISBN 9780672335877), page 314
  Compared to other modern languages, C is much less forgiving, much more terse, and generally much more ill tempered. However, it is about as close to programming on the bare metal as you can get while still using a well-supported language with good library support for everything from numeric calculations to graphics.
2012, Peter Membrey, Eelco Plugge, David Hows, Practical Load Balancing: Ride the Performance Tiger, Apress (ISBN 9781430236818), page 214
  The bare metal hypervisor has a significantly higher level of control over the resources available it because it does not have to go through an intermediary to access the resources.
2013, Bryon Moyer, Real World Multicore Embedded Systems, Newnes (ISBN 9780123914613), page 519
  What is a bare-metal setup? Programs that run on bare metal typically follow a very simple format: they do one thing, more or less forever.
2007, Barb Goldworm, Anne Skamarock, Blade Servers and Virtualization: Transforming Enterprise Computing While Cutting Costs, John Wiley & Sons (ISBN 9780470139554), page 98
  A hypervisor is a thin, guest OS—independent Virtualization layer that is loaded onto bare metal, which interacts with the hardware directly and creates virtual machines in which operating systems, either enlightened or not, can run.
2009, Latifa Boursas, Mark Carlson, Wolfgang Hommel, Michelle Sibilla, Kes Wold, Systems and Virtualization Management: Standards and New Technologies, Springer Science & Business Media (ISBN 9783540887089), page 61
  In 1998 virtualization was "rediscovered" for the x86 platform by VMWare, but due to instruction translation the approach taken was slow when compared to bare metal performance.
2014, S. Srinivasan, Cloud Computing Basics, Springer (ISBN 9781461476993), page 75
  SoftLayer is focused on bare metal servers. Bare metal servers provide a higher level of freedom for the businesses in choosing their virtual servers.