Virtualization: The Good, The Bad, and The Ugly S. Keshav University of Waterloo January 14th, 2010 Mysore Cloud Workshop.

Virtualization: The Good, The Bad, and The Ugly

S. Keshav

University of WaterlooJanuary 14th, 2010

Mysore Cloud Workshop

Overview

Virtualization An example The good, the bad, and the ugly

Virtualization

Creates virtual servers that mimic real servers and hide underlying hardware

Ideal virtualization

Lets unmodified services run on virtual servers

Ideal virtualization

Allows arbitrary mapping from virtual to physical servers

Ideal virtualization

Allows virtual server configuration and location to be arbitrarily modified

Why virtualization for clouds?

Scaling is otherwise impossible

WiFi access network

Proxy3G access network

AP

Internet

Data centerP

Ideally, want one per device

Mobile device

My prediction

Every cloud infrastructure will be virtualized

But…

Experience shows that

Overall, virtualization is good But has some bad points And some downright ugliness

The Good Reduces need for servers, power and space Creates hardware-independent homogeneous

infrastructure Capacity can be changed on demand State capture and rollback for rapid deployment

and disaster recovery Sandboxing prevents application interaction

and increases security

The Bad

Slow New source of bugs New attack surface Adds complexity

The Ugly

Correlated failures Unpredictable loss of emulation Introduces hardware dependencies Rapid spread of attacks More configuration parameters Encourages sloppiness

Conclusion

Virtualization is inescapable But needs care