Högskolan i Skövde

There are several ways to virtualize machines from the different closed source variants as VMware ESXi and Windows Hyper-V virtualization to open source varies as Xen and Kernel-based Virtual Machine (KVM). There is also another way to virtualize parts of an operating system to increase versatility and be able to use more of the system’s resources in a more efficient way. LXC (Linux Containers) is a lightweight virtualization that is run on top of the existing operating system by encapsulating applications that is inside the container. LXC works so the kernel of the Linux system is shared by the containers that run next to each other without much knowledge of each other. In that way it can be more resource efficient than virtualizing the entire Linux kernel several times for different applications in a traditional guest to host environment.

Many data centers today are already using some variant of virtualization in their production environment, it may then be interesting to examine if there are some other methods that result in better performance for chosen application and power savings when hosts can be turned off. That is why this project has carried out a field study to examine how LXC performs when the host system is virtualized in a hypervisor environment. An organization might want to migrate from a hypervisor environment to a lightweight virtualization environment that is based on containers. The work has been done by doing experiments using two different software to examine I/O to determine if LXC is affected by being nested inside ESXi.

The study begins with a small background study to obtain information that will give relevant information from previous done work in relevant fields. The study was conducted with the use of the experimental method to be able to answer the hypothesis and the projects questions.

The questions that was answered in the project was: How much degradation of the file system's read and write speeds arises when LXC is nested in ESXi? Does it affect the file system's ability to read and write to disk when there are restrictions on available resources?

The result of the experiments show that LXC performs close to equal of the bare metal systems, with a 2 percent loss as a minimum and a maximum of 11 percent in write and read ability to/from disk. When LXC is intertwined with ESXi there is an up to 15 percent loss in write and read ability excluding the loss the hypervisor adds. When restricting the resources for a container down to one processor core and two gigabytes of primary memory experiments show that there was a 3 to 15 percent loss in write and read ability from the disk