# 十一：实现Linux KVM在线迁移 在KVM中，你可以从一台主机迁移一个KVM虚拟机到另外一台主机而无须宕机。如果两个KVM物理服务器访问共享的存储池，KVM在线迁移可以完美运行。要在两个KVM主机上访问共享的存储池，你需要使用NFS或者GFS2文件系统（集群文件系统）。在这个案例中，我使用NFS文件系统来存储VM镜像。在迁移过程中，VM的"内存"内容将复制到目标KVM物理主机，并且在某个时间点相同内容时切换来迁移VM。注意，当在KVM主机间使用共享文件系统，VM的磁盘镜像不在通过网络复制，这样两个KVM物理主机将访问相同的存储池。 ![KVM热迁移](/files/-M1TAEpK4SqxXnDOsgUI) ## 环境 * KVM物理主机 – UA-HA 和 UA-HA2 * VM名字 – UAKVM2 存储池： ``` [root@UA-HA ~]# df -h /kvmpool/ Filesystem Size Used Avail Use% Mounted on 192.168.203.134:/kvmstore 1.8G 1.7G 88M 96% /kvmpool [root@UA-HA ~]# ssh UA-HA2 df -h /kvmpool/ Filesystem Size Used Avail Use% Mounted on 192.168.203.134:/kvmstore 1.8G 1.7G 88M 96% /kvmpool [root@UA-HA ~]# ls -lrt /kvmpool total 1710924 -rw------- 1 root root 4295884800 Dec 22 18:07 UAKVM2.qcow2 [root@UA-HA ~]# ``` > 你必须在KVM主机之间配置`无须密码的root登录ssh`来立即启动迁移以避免root用户密码提示。 * 当 ## 系列教程编译 本系列教程根据 [UnixArena Linux KVM](http://www.unixarena.com/category/redhat-linux/linux-kvm) 系列教程编译，共分以下文章： * [一：基于内核的虚拟机（KVM）概览](https://github.com/huataihuang/cloud-atlas-draft/tree/6f3204fffc11cf006abd394631e2598d98b415c3/virtual/kvm/startup/kernel_based_virtual_machine_kvm_overview/README.md) * [二：Redhat企业Linux安装KVM](https://github.com/huataihuang/cloud-atlas-draft/tree/6f3204fffc11cf006abd394631e2598d98b415c3/virtual/kvm/startup/redhat_enterprise_linux_kvm_installation/README.md) * [三：RHEL 7.2 配置KVM主机](https://github.com/huataihuang/cloud-atlas-draft/tree/6f3204fffc11cf006abd394631e2598d98b415c3/virtual/kvm/startup/rhel_7_2_configuring_kvm_hosts/README.md) * [四：使用命令行启动第一个KVM实例](https://github.com/huataihuang/cloud-atlas-draft/tree/6f3204fffc11cf006abd394631e2598d98b415c3/virtual/kvm/startup/launch_the_first_kvm_instance_using_cli/README.md) * [五：使用Virt-Manger(VMM)部署KVM实例](https://github.com/huataihuang/cloud-atlas-draft/tree/6f3204fffc11cf006abd394631e2598d98b415c3/virtual/kvm/startup/deploy_kvm_instance_using_virt_manger_vmm_gui/README.md) * [六：如何克隆一个KVM虚拟机并重置该虚拟机](https://github.com/huataihuang/cloud-atlas-draft/tree/6f3204fffc11cf006abd394631e2598d98b415c3/virtual/kvm/startup/how_to_clone_a_kvm_virtual_machines_and_reset_the_vm/README.md) * [七：如何在线添加/更改虚拟磁盘](https://github.com/huataihuang/cloud-atlas-draft/tree/6f3204fffc11cf006abd394631e2598d98b415c3/virtual/kvm/startup/how_to_add_resize_virtual_disk_on_fly/README.md) * [八：如何在线添加/移除虚拟机的内存](https://github.com/huataihuang/cloud-atlas-draft/tree/6f3204fffc11cf006abd394631e2598d98b415c3/virtual/kvm/startup/how_to_add_remove_memory_to_guest_on_fly/README.md) * [九：如何在线添加/移除虚拟机的vCPU](https://github.com/huataihuang/cloud-atlas-draft/tree/6f3204fffc11cf006abd394631e2598d98b415c3/virtual/kvm/startup/how_to_add_remove_vcpu_to_guest_on_fly/README.md) * [十：更改libvirt虚拟机镜像存储路径](https://github.com/huataihuang/cloud-atlas-draft/tree/6f3204fffc11cf006abd394631e2598d98b415c3/virtual/kvm/startup/change_libvirt_vm_image_store_path/README.md) * [十一：实现Linux KVM在线迁移](https://github.com/huataihuang/cloud-atlas-draft/tree/6f3204fffc11cf006abd394631e2598d98b415c3/virtual/kvm/startup/perform_live_migration_on_linux_kvm/README.md) * [十二：RHEL7 Pacemaker - 配置高可用KVM虚拟机](https://github.com/huataihuang/cloud-atlas-draft/tree/6f3204fffc11cf006abd394631e2598d98b415c3/virtual/kvm/startup/rhel_7_pacemaker_configuring_ha_kvm_guest/README.md) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://huataihuang.gitbook.io/cloud-atlas-draft/virtual/kvm/startup/perform_live_migration_on_linux_kvm.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.