Some Interactions Between Server Virtualization and Networking. Mendel Rosenblum

Transcription

1 Some Interactions Between Server Virtualization and Networking Mendel Rosenblum

2 Talk Outline What is networking? What is virtualization? The new virtualized data center Interactions with the network Some neat possibilities for network

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4 What is virtualization? A level of indirection Existing in data center: Storage virtualization LUNs Storage area networks Network virtualization VLANs

5 Server Virtualization Application Operating System Virtualization

6 Traditional View Exchange Operating System Operating System Virtualization File/Print Operating System Operating System Virtualization VPN Operating System Operating System Virtualization CRM Operating System Operating System Virtualization

7 The New Datacenter File/Print VPN Exchange CRM Operating System Operating System Operating System Operating System CPU Virtual Infrastructure Memory Storage Interconnect

8 Resource Mapping

9 Exchange CRM File/Print Virtual Infrastructure CPU Memory Storage Interconnect

10 High Availability

11 Exchange CRM File/Print Virtual Infrastructure CPU Memory Storage Interconnect

12 Desktop

13 Mixed Server Workloads Including Hosted Desktops File/Print Virtual Infrastructure CPU Memory Storage Interconnect Remote Clients

14 Power Management

15 File/Print Virtual Infrastructure CPU Memory Storage Interconnect Active Idle Powered Down

16 LOGICAL VIEW User s view of virtualization MAIL SERVICE VM VM VM Server VM--Exchange Exchange CRM Server CPU CPU Memory Memory Disk Disk Network Network WEB STORE 2x1 2x1GHZ GHZ 22GB GB GB GB 11GB GB PHYSICAL VIEW Fault ; Faulttolerance tolerance ; Virtualization LayerDisaster - Optimize HW utilization, power, etc. recovery ; Disaster recovery ; COMPUTE Security Security STORAGE SANs/NAS ; ; INTERCONNECT

17 Key low-level VMM operations App App VMM Hardware VMM App Hardware Multiplex Suspend Resume (Provision) Migration Storage App

18 VMM Implementation Application Application Operating System Operating System Virtual Machine Monitor

19 ESX 3 Network Architecture Virtual NICs VM VM VM VM Service Console ESX Sever 3 Virtual Switches Physical NICs Production LANs Management LAN

20 Virtual Switches Virtual Switch Physical Switch Multiple Client MAC addresses appear on this port Virtual Switch behaves like a dumb switch Optional CDP

21 VMotion - VM migration RARP VMotion moves the VM from one physical switch port to another (or different switch altogether) Source and destination port should be in the same broadcast domain (implies same VLAN). Virtual NIC is unplugged on the source and plugged back at the destination host triggers switch notification

22 Load Balancing: IP hash (out-ip) Virtual Switch Physical Switch A B C Outbound NIC is chosen based on Sourcedestination L3 address pair Scalability is dependent on the no of TCP/IP sessions to unique destinations. No benefit for bulk transfer between hosts Physical switch will see the client MAC on multiple ports Can disrupt switch MAC learning process Inbound traffic is unpredictable.

23 NIC teaming Link aggregation Virtual Switch Allows load balancing of incoming traffic. Throughput aggregation benefits are less relevant with the advent of gigabit and 10G Links Physical Switch

24 Network policy: security Administrators can configure Layer 2 Ethernet security options at the virtual switch There are three security policy exceptions: Promiscuous Mode MAC Address Changes Forged Transmits

25 Network policy: traffic shaping Network traffic shaping is a mechanism for controlling a VM s outbound network bandwidth Average rate, peak rate, and burst size are configurable

26 Stanford Research with Ben Pfaff

27 Paravirtualization Modify operating system to reduce virtualization overheads Example: MMU Example: NIC drivers App App App App App Operating System Operating System Operating System Virtual Machine Monitor (VMM) Hardware

28 NIC Paravirtualization Hardware App Kernel Driver NIC Driver Specialized virtual network interfaces Rather than hardware interface, go in at NIC Driver Ease driver install Simple ring buffer interface Less virtualization overhead, higher performance

29 Interfaces in modern operating system Socket Hardware App Networking Stack Driver System Call NIC Driver What happens if you go in at the socket interface? Ops: socket(), listen(), send(), receive() Move networking stack out of and into virtualization layer.

30 Pull networking stack into virtualization layer App App Operating System Driver Virtual Machine Monitor (VMM) Hardware Network Stack Need low-overhead inter-vm communication mechanism

31 Benefits of pulling out network Enforced modularity Performance - A shared networking stack across VMs Share IP address with NAT Specialization - Can choose networking stack based on applications VMs on same machine? VMs in same room or across world? Security - Moved networking stack into trusted place Could remotely attest

32 Question for networking community Would it be useful to control networking stack? Dynamic select?

33 Conclusions Server virtualization impacts network and storage virtualization Opens new possibilities