Course Review. Hui Lu

Transcription

1 Course Review Hui Lu

2 Syllabus Cloud computing Server virtualization Network virtualization Storage virtualization Cloud operating system Object storage

3 Syllabus Server Virtualization Network Virtualization Storage Virtualization Object Storage Open stack Others

4 Cloud Computing Cloud definition Why cloud? Three service models

5 Syllabus Cloud computing Server virtualization Network virtualization Storage virtualization Cloud operating system Object storage NoSQL

6 Server Virtualization Different ways to share physical machines Sensitive instructions vs. privilege instructions virtualizable? CPU rings Three solutions to realize CPU virtualization Binary Translation Para-virtualization Hardware-assistant virtualization Resource sharing --- process-based, container-based vs. virtualization based Container --- two main techniques

7 Server Virtualization Two concrete examples: Xen Hypercall Memory virtualization (Hardware MMU vs. Software MMU) Xen Split driver model why and how and the problem Credit-based scheduler How to schedule mixed --- vturbo is an example KVM Differences between Xen and KVM VMExits Main overheads

8 Server Virtualization I/O path optimization Legacy virtio vhost Vt-d SR-IOV Server consolidation

9 Syllabus Cloud computing Server virtualization Network virtualization Storage virtualization Cloud operating system Object storage

10 Software-defined Networking Traditional computer networks -- Packet switching, best effort 7 or 5 layers of network models Motivations of software-defined networking Control plane and data plane (Why separation, what benefits) Two abstractions of the control plane Global view and forwarding model Realization of these two parts network OS and OpenFlow OpenFlow how it works, flow tables (examples) Hybrid solution --- involving both legacy and SDN switches --- how to manage them?

11 Traditional Network Feature Feature Feature Feature Feature 11

12 Logically-centralized control Software Defined Network (SDN) Smart, slow 3. Consistent, up-to-date global network view 2. At least one Network OS probably many. Open- and closed-source Feature Feature Network OS/Controller 1. Open interface to packet forwarding Dumb, fast 12

13 Network Operating Systems AppAppAppAppAppAppAppAppAppAppApp Open Interface Network Operating System Open Interface OpenFlow Merchant Switching Chips 13

14 E.g.: Dynamic Access Control Inspect first packet of a connection Consult the access control policy Install rules to block or route traffic 14

15 Network Virtualization We have to solve the isolation and connectivity problems Solutions: VLANs Tunnel network virtualization Main steps of GRE tunneling GRE realization in virtualization via OpenStack Connections virtual routers (gateways) How they relate to Network Services in OpenStack

16 Syllabus Cloud computing Server virtualization Network virtualization Storage virtualization Cloud operating system Object storage

17 Block Storage Vitualized Devices: Pre-allocated vs. Extensive disk images (raw disks vs. QCOW) Copy-on-writes and its application I/O resource sharing and, problems and solutions Physical Devices: HDD vs. SSD Main issues of SSD, how to solve it Storage Setup (storage area network): iscsi vs. Fibre channel Different levels of data reliability What, why and how data deduplication

18 I/O Layers in Virtualization VM1 Applications System Call Interfaces VFS File System (ext3, ext4, btrfs) Page Cache Generic Block Layer I/O schedulers Block device driver QEMU Device Hypervisor/ Host KVM Module System Call Interfaces VFS File System (ext3, ext4, btrfs) Page Cache Generic Block Layer I/O schedulers Block device driver Question 1: Dual I/O stack how to optimize? 18

19 Syllabus Cloud computing Server virtualization Network virtualization Storage virtualization Cloud operating system Object storage

20 OpenStack How a VM is created (what are the main components involved during this process)?

21 Syllabus Cloud computing Server virtualization Network virtualization Storage virtualization Cloud operating system Object storage

22 Object Storage Why object storage? Block storage vs. object storage Design comparison: Swift vs. Ceph Consistent Hashing Algorithm (related problems and solutions) Reliability Replication vs. Erasure code