Desktop PCs in enterprise offices are often powered on at night and holiday times, when no one is actually using them, but sporadic access from remote locations may be required. We develop a solution that allows the desktop PCs to be put into sleep mode at such times while ensuring that (1) remote users can connect to the sleeping machines, such as to access files or to work remotely and (2) IT administrators and automated scripts can execute any required maintenance tasks without interruption.
Enterprise desktop computers consume an estimated 65TWh/year of energy. A typical desktop with a 17 inch LCD consumes over 100W when powered on. A sleeping computer consumes only 2-3W.
But while most people turn off the lights when not around, they leave their PCs powered on. The reason is that they may need to access some file remotely when away at a meeting, or working on a report at home, and so on. Also, IT depertments may update the machines or perform other maintenance tasks using automated scripts that require the machines to be powered on and available on the network.
We propose a solution where a desktop can be put to sleep whenever the user is not using it. We maintain a proxy representing the desktop in the enterpise cloud that allows the desktop to pretend to be available on the network even when sleeping, and wakes up the desktop automatically when needed by a user or an automated script.
The solution provides the following two methods for enabling transparent sleep:
SleepServer: A proxy machine maintains the network presence of the sleeeping machine and wakes it up when a valid application or user needs the machine.
- is easy to deploy
- has a small footprint on the proxy machine
- does not need any special hardware on the desktops served
- causes some disruption
LiteGreen: A proxy server continues to host the user desktop as a virtual machine when the desktop goes to sleep. The desktop is woken up when needed for active use.
- has zero disruption
- supports all applications seamlessly
- does not need special hardware on the desktops served
- requires virtual machines to be deployed on all desktops served
Both methods may be used at the same time to combine their advantages.
Pradeep Padala (intern, University of Michigan), Joshua Reich (intern, Columbia University)
- Joshua Reich, Michel Goraczko, Aman Kansal, and Jitu Padhye, Sleepless In Seattle No Longer, in USENIX Annual Technical Conference, USENIX, 22 June 2010.