abstract: Virtualization technologies are widely used in modern computing systems to deliver shared resources to heterogeneous applications. Virtual Machines (VMs) are the basic building blocks for Infrastructure as a Service (IaaS), and containers are widely used to provide Platform as a Service (PaaS). Although it is generally believed that containers have less overhead than VMs, an important tradeoff which has not been thoroughly studied is the effectiveness of performance isolation, i.e., to what extent the virtualization technology prevents the applications from affecting each other’s performance when they share the resources using separate VMs or containers. Such isolation is critical to provide performance guarantees for applications consolidated using VMs or containers. This paper provides a comprehensive study on the performance isolation for three widely used virtualization technologies, full virtualization, para-virtualization, and operating system level virtualization, using Kernel-based Virtual Machine (KVM), Xen, and Docker containers as the representative implementations of these technologies. The results show that containers generally have less performance loss (up to 69% and 41% compared to KVM and Xen in network latency experiments, respectively) and better scalability (up to 83.3% and 64.6% faster compared to KVM and Xen when increasing number of VMs/containers to 64, respectively), but they also suffer from much worse isolation (up to 111.8% and 104.92% slowdown compared to KVM and Xen when adding disk stress test in TeraSort experiments under full usage (FU) scenario, respectively). The resource reservation tools help virtualization technologies achieve better performance (up to 85.9% better disk performance in TeraSort under FU scenario), but cannot help them avoid all impacts. / Dissertation/Thesis / Masters Thesis Computer Science 2019

This work deals with virtualization of computer systems and network cards in high-speed computer networks, and describes implementation of the SR-IOV virtualization technology support in the COMBO network card platform. Various approaches towards network card virtualization are compared, and the benefits of the SR-IOV technology for high performance applications are described. The work gives overview of the COMBO platform and describes design and implementation of the SR-IOV technology support for the COMBO platform. The work concludes with measurement and analysis of the implemented technology performance in virtual machines. The result of this work is the COMBO cards' support for the SR-IOV technology, which makes it possible to use them in virtual machines with wire-speed performance preserved. This allows future COMBO cards to be used as accelerators in the networks utilizing the Network Function Virtualization.

Existuje veľa rôznych dôvodov pre spoločnosti a organizácie, prečo by mali investovať do virtualizácie. Asi najväčší dôvod je finančná motivácia, pretože nasadenie virtualizácie môže ušetriť nemálo peňazí. Táto práca sa zaoberá práve problémom virtualizácie I/O operácií v sieťovom prostredí. Cieľom práce je tvorba softvérových ovládačov pre I/O virtualizáciu, ktoré by mohli pracovať s hardvérovo akcelerovanými sieťovými kartami. Hlavným prínosom ovládačov by mala byť použiteľnosť a čo najmenšia strata prenosového výkonu vo virtualizovanom prostredí. Pred popisom finálnych detailov ovládačov je však potrebné uviesť potrebné teoretické základy. Teoretická časť sa zaoberá súčasnými trendami vo virtualizácii I/O, technológiami ako sú virtio, vhost, SR-IOV, VFIO a mdev. V praktickej časti sú navrhuté dva spôsoby riešenia problému. Prvým je použitie technológie virtio (emulácia softvéru). Druhé je založené na technológii VFIO-mdev (hybridná paravirtualizácia). Pokiaľ sa jedná o výkon a konfigurovateľnosť zariadení, oba prístupy majú rôzne benefity. Tieto riešenia majú aj svoje nevýhody, ako je zložitosť riešenia a náročnosť integrácie do systému. Požadované ciele boli úspešne dosiahnuté vo forme prototypu ovládača nfb_mdev.