Basic principles of Virtualization Technology

Disk:

IO Scheduler

CFQ

Deadline

Anticipatory

NOOP

/ sys/block//queue/scheduler

Memory:

MMU two kinds of memory chips

TLB

Vm.swapiness= (0.. 100); propensity to use swap partitions, 60

Overcommit_memory: overuse

Overcommit_ratio

Make full use of physical memory:

1. Swap is as big as RAM, swappiness=0

2 、 overcommit_memory=2, overcommit_ratio=100, swappiness=0

Tcp_max_tw_buckets: turn it up

Tw: number of connections

Established-- > tw

Sar, dstat, vmstat, mpstat, iostat, top, free, iotop, uptime, cat / proc/meminfo, ss, netstat, lsof, time, perf, strace, blktrace, blkparse, btt

Dd, iozone, io-stress, fio

Look at the physical hardware from the perspective of each OS:

CPU: full CPU time slice

Memory: continuous, all memory space (0x0000)

IO: all available IO

Hypervisor Virtualization Software

Virtualized network model:

Bridging

NAT

HOST Only

CPU Virtualization:

CPU instruction set:

General instruction

Special instruction (sensitive instruction)

Some x86 sensitive instructions cannot be virtualized

Basic conditions that virtualization software needs to meet:

CPU hardware Virtualization Technology:

Intel VT-x

AMD AMD-V

Memory Virtualization:

VA without Virtualization-- > PA

VA-- > PA VA-- > HA shadow MMU Intel EPT AMD NPT when there is virtualization

TLB: hardware chip

Full-Virtualization: fully virtualized HVM (Hardware-asistant VM)

Para-virtualization: paravirtualized PV

Integration of PV and HVM

PV on HVM:

IO Virtualization:

QEMU

PV

IO requires high performance and can be transmitted through IO.

Practical operation: compatibility list

Xen Virtualization Architecture

Xen only manages CPU, Memory, interrupt

Qemu: virtualization tool, can also cross-platform virtual CPU is X86 can simulate PowerPC, ARM platform

Xend/xm

Redhat virsh

Openstack

KVM Virtualization Kernel-based Virtual Machine

KVM: kernel module Kernel-- > Hypervisor

The performance of KVM using CPU is better than CPU simulated by Qemu.

KVM can only run on 64-bit operating systems and must run on CPU-assisted virtualization.

KVM is an Israeli company acquired by redhat

Xen is developed by the University of Cambridge and acquired by Citrix.

KVM:virtio (PV IO)

Container: containers are less isolated and perform much better than virtual machines

Simulating .netframework in wine linux environment

Cywin windows environment simulates linux environment

Virtualization technology:

Motherboard chipset:

Intel: IOMMU

AMD:

The virtualization technology of X86 platform is more and more simple and mature.

Intel VT-x 、 EPT 、 IOMMU

The network model is complicated.