[Ubuntu] KVM+QEMU 使用筆記 (Ubuntu 14.04)

• 安裝指令
  
  #apt-get install qemu-kvm qemu-system libvirt-bin bridge-utils


• 建立Image檔
  qemu-img
  
  check[-q] [-f fmt] [--output=ofmt] [-r [leaks | all]] filename
  
  create [-q] [-f fmt] [-o options] filename [size]
  
  commit [-q] [-f fmt] [-t cache] filename
  
  compare [-f fmt] [-F fmt] [-p] [-q] [-s] filename1 filename2
  
  convert [-c] [-p] [-q] [-n] [-f fmt] [-t cache] [-O output_fmt] [-o options] [-s snapshot_id_or_name] [-l snapshot_param] [-S sparse_size] filename [filename2 [...]] output_filename
  
  info [-f fmt] [--output=ofmt] [--backing-chain] filename
  
  map [-f fmt] [--output=ofmt] filename
  
  snapshot [-q] [-l | -a snapshot | -c snapshot | -d snapshot] filename
  
  rebase [-q] [-f fmt] [-t cache] [-p] [-u] -b backing_file [-F backing_fmt] filename
  
  resize [-q] filename [+ | -]size
  
  amend [-q] [-f fmt] -o options filename
  
  [-f fmt] : raw|qcow2|qcow|vmk|cloop
  
  Example:
  qemu-img create -f qcow2 linux.img 5G


• Create Virtual Machine
  qemu-system-{cpu-architecute} [--enable-kvm]  [-smp options] [-boot dev] [-m size] [-cdrom iso] [-soundhw sdev] [-net nic] [-vnc conn] [-k keyboard] [-netdev options] [disk options] [-monitor options] [--enable-kvm]
  
  [--enable-kvm] : 啟動KVM能力，該功能CPU必須支援
      1. #egrep 'vmx|svm' /proc/cpuinfo
  
  [--smp options] :
      1. -smp [current allocation] [,maxcpus=n] [,sockets=n] [,cores=n] [,threads=n]     ( Example : -smp 2,maxcpus=4,sockets=4,cores=2,threads=2 )
  
  [-boot dev] : a, b (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot from network adapter 1-4)
  
  [-m size] : memory size , default M
  
  [-cdrom iso] : 加入 cdrom
  
  [-soundhw sdev] : 加入 sound card
  
  [-vnc conn] :
      1. conn = host:port,password
      2. conn = host:port,tls,x509=/path
      3. conn = host:port,tls,x509verify=/path
  
  [-k keyboard]  keyboard layout
  
  [-netdev options]    
      1. -netdev nic [,vlan=n] [,macaddr=mac] [,model=type] [,name=name] [,addr=addr]
      2. -netdev tap [,vlan=n][,name=name][,fd=h][,ifname=name][,script=file][,downscript=dfile][,helper=helper]
      3. -netdev bridge ,id=id[,br=bridge][,helper=helper] -net bridge[,vlan=n][,name=name][,br=bridge][,helper=helper]
      4. -netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]
      5. -netdev none
   
  [nic] : 建立一個網路卡，並且連接至VLAN n ( n預設為0 )
  [tap] : 連接到host TAP的網路介面
  [bridge] : Bridge 模式，
  [vhost-user]
  [type] : [virtio|i82551|i82557b|i82559er|ne2k_pci|ne2k_isa|pcnet|rtl8139|e1000| smc91c111|lance|mcf_fec]
  
  [disk options] :
      1. -drive file=[path] ,if=none [,id=id_name] [,format=qow2] -device virtio-blk-pci,drive-virtio-disk0,id=virtio-disk0 [,bootindex=1]
      ( Example : -drive file=/images/ubuntu-14.04.img,if=none,id=drive-virtio-disk0,format=qcow2 -device virtio-blk-pci,drive=drive-virtio-disk0,id=virtio-disk-0,bootindex=1 )
  
  
  [-monitor options] :
      1. -monitor stdio
      2. -monitor telnet:[bind_ip]:[port] [,server] [,nowait] [,nodelay]
      ( Example : -monitor telnet::7000, server, nowait, nodelay )
     
  Example 1 : (安裝 Guest OS )
  qemu-system-x86_64 --enable-kvm -smp 2,maxcpus=4,sockets=4,cores=2,threads=2 linux.img -cdrom ubuntu-14.04-server-amd64.iso -boot d -vnc :0,password -k en-us -netdev nic -monitor stdio
  
  


• Virtual Machine相關指令
  
  #telnet  host  port
  
  // 暫停/恢復/重置
  (qemu) stop  #暫停VM
  (qemu) cont #恢復VM
  (qemu) system_reset #重新啟動 VM
  (qemu) system_poweddown  #送ACPI Shutdown request
  (qemu) quit #關閉
  
  // Memory 相關
  (qemu) memsave    #儲存 Virutal memory 資料
  (qemu) pmemsave    #儲存 Physical memory 資料
  
  // Snapshot 相關
  (qemu) savevm name    #建立Snapshot
  (qemu) loadvm name    #恢復Snapshot
  (qemu) delvm    #刪除Snapshot
  (qemu) info snapshot    #顯示可用的Snapshot


• NAT網路設定
  
  //-------Host OS 設定-------
  //安裝 tap tool
  #apt-get install uml-utilities
  
  //KVM Command
  #qemu-system-x86_64 linux.img --enable-kvm -vnc :0,password -k en-us -netdev nic -monitor stdio
  
  // 建立通道
  #tunctl -t tap0
  
  // 設定iptables
  #echo 1 > /proc/sys/net/ipv4/ip_forward
  #iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
  #iptables -I FORWARD 1 -i tap0 -j ACCEPT
  #iptables -I FORWARD 1 -o tap0 -m state --state RELATED,ESTABLISHED -j ACCEPT
  
  //-------Guest OS 設定-------
  ip address : 192.168.100.2
  gateway : 192.168.100.1
  dns : 192.168.100.1


• Bridge網路設定
  
  //-------Host OS 設定-------
  //安裝Bridge
  #apt-get install bridge-utils
  
  //建立Bridge
  #brctl addbr br0
  #brctl addif br0 eth0
  
  //KVM Command
  #qemu-system-x86_64 linux.img --enable-kvm -netdev tap,id=hostnet0,ifname=vnet0,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet0,id=net0 -vnc :0,password -k en-us -monitor stdio


• 設定VLAN(802.1Q)

  

  VLAN示意圖

  要對某VM送出或進來的封包執行802.1Q，方法很簡單，只需要將VLAN和VNet0以起綁定至br0.2即可，如VLAN示意圖所示。
  
  
  //安裝vlan tools
  #apt-get install vlan
  
  //設定VLAN，假設VLAN為2
  #vconfig add eth0 2
  
  //建立新的Bridge，並且綁定eth0.2
  #brctl addbr br0.2
  #brctl addif br0.2 eth0.2
  
  //修改 /etc/qemu-ifup
  switch=br0.2
  for br in $switch; do
    if [ -d /sys/class/net/$br/bridge/. ];then
      brctl addif $br vnet0
    fi
  done
  
  //KVM Command
  #qemu-system-x86_64 linux.img --enable-kvm -netdev tap,id=hostnet0,ifname=vnet0,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet0,id=net0 -vnc :0,password -k en-us -monitor stdio

Reference:
[1] 架設Linux KVM虛擬化主機 (Set up Linux KVM virtualization host)
[2] QEMU Emulator User Documentation
[3] Chapter 14. Administrating Virtual Machines with QEMU Monitor
[4] 使用 monitor command 监控 QEMU 运行状态 
[5] Setting up QEMU with a NAT
[6] CentOS + KVM 建立 VLAN 的方式
[7]  KVM虚拟化技术之使用Qemu-kvm创建和管理虚拟机