Unikernels are famous for providing excellent performance in terms of boot times, throughput and memory consumption, to name a few metrics. However, they are infamous for making it hard and extremely time consuming to extract such performance, and for needing significant engineering effort in order to port applications to them. We introduce Unikraft, a novel micro-library OS that (1) fully modularizes OS primitives so that it is easy to customize the unikernel and include only relevant components and (2) exposes a set of composable, performance-oriented APIs in order to make it easy for developers to obtain high performance.

Increasingly, embedded devices are being equipped with ARM processors. Because of ease-of-use and widespread support for drivers and applications, Linux is often used as the OS of choice, even though it consumes a significant amount of the device's limited resources and its large attack surface presents opportunities for exploits. In this paper we propose Unikraft, a fully librarized operating system and build tool which allows for generating specialized OSes and software stacks targeting specific applications, while removing unneeded functionality. As a proof of concept, we port Unikraft to the Raspberry Pi 3 B+ and to a Xilinx Ultra96-V2. On these boards, Unikraft is able to boot in 88-158 milliseconds, consume only hundreds of KBs of memory when running real-world application such as NGINX, all the while providing visible reductions in power consumption compared to Linux distributions. Unikraft is an open source project and can be found at unikraft.org.

Recent research has shown that unikernels, lightweight virtual machines tailored to specific applications, have great potential in terms of performance, tiny boot times, small memory consumption, and a reduced trusted compute base. Creating and optimizing them, however, is currently a painful, time-consuming process that often needs redoing for every application. With Unikraft, we introduce a system for automatically building unikernels that drastically reduces this time without negatively impacting performance.

As enterprises shift from using direct-attached storage to network-based storage for housing primary data, flash-based, host-side caching has gained momentum as the primary latency reduction technique. In this paper, we make the case for integration of flash caching algorithms at the file level, as opposed to the conventional block-level integration. In doing so, we will show how our extensions to Loris, a reliable, file-oriented storage stack, transform it into a framework for designing layout-independent, file-level caching systems. Using our Loris prototype, we demonstrate the effectiveness of Loris-based, file-level flash caching systems over their block-level counterparts, and investigate the effect of various write and allocation policies on the overall performance.