VMLite Workstation vs. Lguest

VMLite Workstation is a virtualization software that allows several operating systems to run simultaneously on a single physical computer. For example, it provides the ability to operate Windows XP in conjunction with a running Windows 7 environment. This program manages the OS and applications directly on top of an existing system without necessitating any changes. The platform where the unmodified OS and applications function is known as a "Virtual Machine," which possesses features similar to a physical computer. Generally, the actual device is referred to as the "host," while the virtual representation is classified as the "guest." The OS that runs on the physical hardware is called the "Host Operating System," and the OS operating within the virtual guest is known as the "Guest Operating System." Such a configuration enhances the efficiency and adaptability of managing various software setups on a single device. Additionally, this capability is particularly beneficial for developers and testers who need to work across multiple environments seamlessly.

Lguest allows for the simultaneous operation of multiple instances of a 32-bit kernel, and you can start it by executing the command modprobe lg followed by Documentation/lguest/lguest to create a new guest. I highly recommend trying it out because lguest is incredibly easy to set up and use. Its advantages are noteworthy: I can boot kernels for testing in under a second, which is about ten times faster than qemu and a hundred times quicker than traditional boot methods. Furthermore, by utilizing a pty for console access, you can perform operations like piping outputs through grep. Lguest includes a full kernel patch, featuring the launcher, and is compatible with versions 2.6.23-git13 and newer. The main purpose of lguest is to maintain the isolation of guests, preventing them from directly accessing the host system, except via virtual devices provided by the host, even in cases where the guest may pose a security threat. However, a potentially dangerous guest kernel can still pin host memory, but this is restricted to the amount allocated for the guest itself. While many images are set up to create virtual consoles such as (/dev/tty0, etc.), lguest designates its console as /dev/hvc0, which enhances its functionality. This unique console setup, along with its rapid boot times, makes lguest an invaluable resource for developers looking to efficiently test kernel modifications without the complexities associated with full virtualization environments. Thus, lguest stands out as both a practical tool for quick testing and a means to ensure the integrity of the host system.