Virtualizare sub Linux: avantaje si pericole. Dragos Manac

Transcription

1 Virtualizare sub Linux: avantaje si pericole Dragos Manac 1

2 Red Hat Enterprise Linux 5 Virtualization

3 Major Hypervisors Xen: University of Cambridge Computer Laboratory Fully open sourced Set of patches against the linux kernel Vmware ESX : Closed source Based on Linux 2.4 Proprietary drivers Xbox 360: Closed source, used to assume full backward compatibility with the old Xbox 3

4 Why Xen? Supported by leading software and hardware vendors XenSource Red Hat IBM Intel AMD Novell Widely accepted by open source community Not just Linux *BSD, Open Solaris, Plan

5 Xen Architecture

6 Xen Architecture Domain 0 Domain 1 Front end driver Domain 2 Front end driver Back End Device Driver Virtual CPU & Memory Hypervisor Hardware 6

7 Xen Architecture Domain 0 Privileged domain (Dom0) Provides hardware support Uses native Linux device drivers Provides Back end interface Control facilities for guests Management tools 7

8 Xen Architecture Domain U Virtualised Guest Domain (DomU) Unprivileged Domains (guests) Controlled and initialized from Dom0 Use Front end drivers Simple device drivers that interface to the back end layer in Dom0 Multiple DomU's can be created Virtual network cards can be created to access network resources 8

9 Xen Architecture Block Devices Block Devices (disks) are connected to domains File in Domain 0 eg. /opt/vm/disk.img Disk image can be a single file system or a complete disk image including partitions Simple to implement but bottleneck for high I/O deployments Physical device eg. /dev/sda6 Logical volume Using LVM or CLVM Devices appear as simple virtual disks in Dom U 9

10 Application Domain 1 Live Migration Domain 1 running on physical machine A is to be moved to Machine B Currently users are accessing Machine A RHEL RHEL Red Hat Enterprise Linux Xen Hypervisor Hardware CPU(s) IO Memory Red Hat Enterprise Linux Xen Hypervisor Hardware CPU(s) IO Memory Machine A Machine B 10

11 Application Domain 1 Domain 1 Live Migration Step 2 : Initialize container on Machine B RHEL RHEL RHEL Red Hat Enterprise Linux Xen Hypervisor Hardware CPU(s) IO Memory Red Hat Enterprise Linux Xen Hypervisor Hardware CPU(s) IO Memory Machine A Machine B 11

12 Application Domain 1 Domain 1 Live Migration Step 3 : Machine A commits ~10% of resources to migration Start shadow paging RHEL RHEL RHEL Red Hat Enterprise Linux Xen Hypervisor Hardware CPU(s) IO Memory Red Hat Enterprise Linux Xen Hypervisor Hardware CPU(s) IO Memory Machine A Machine B 12

13 Application Domain 1 Domain 1 Live Migration Step 4 : Domain 1 is suspended on Machine A Remaining dirty pages copied RHEL RHEL RHEL Red Hat Enterprise Linux Xen Hypervisor Hardware CPU(s) IO Memory Red Hat Enterprise Linux Xen Hypervisor Hardware CPU(s) IO Memory Machine A Machine B 13

14 Migration Performance Source: XenSource 14

15 Red Hat Enterprise Linux Advanced Platform Server and storage virtualization extends across multiple systems Extend Shared Storage 15

16 Virtualization: Performance 16

17 RHN Virtualization Red Hat Network supports virtualization Best suited to Satellite model for quick deployment (lan speeds) Easy web interface Ability to start, pause, halt and deploy Virtual Machines Easy cloning of physical machines to virtual and vice versa Same patch management than physical machines Kickstart subsystem aware of virtualization Ability to deploy dom0's or domu's 17

18 Global File System - GFS SAN Storage Pool Cluster File System Native 64 bit Highly Scalable POSIX compliant Tightly integrated with Red Hat Enterprise Linux Proven technology RAC certified 18

19 Things can go wrong System Load 19

20 Things can go (and will) wrong Software compatibility 20

21 Things can go (and will) wrong Hardware compatibility 21

22 Things can go (and will) wrong I/O Performance 22

23 Things can go (and will) wrong Single Point of Failure 23

24 redhat.sns.ro (partener) redhat - AT - sns.ro (info) 24