Live Update for Device Drivers

Abstract

As commodity operating systems become more reliable and fault-tolerant, the availability of a system will be determined not by when it crashes, but instead by when it must be shutdown and rebooted due to software maintenance. While many system components can be upgraded on-line, critical low-level components, such as device drivers and other kernel extensions, cannot be updated without rebooting the entire operating system.

In this paper, we present Live Update, a mechanism that allows device drivers to be updated without rebooting the system. Unlike other on-line update mechanisms, our system supports existing drivers "as is". Thus, thousands of existing device drivers can be updated transparently. In experiments we show that Live Update can upgrade existing drivers without rebooting and that the system imposes very little performance overhead.