第 11 章 移​​​​​​​植​​​​​​​域​​​​​​​

移​​​​​​​植​​​​​​​是​​​​​​​把​​​​​​​运​​​​​​​行​​​​​​​的​​​​​​​虚​​​​​​​拟​​​​​​​域​​​​​​​从​​​​​​​一​​​​​​​台​​​​​​​物​​​​​​​理​​​​​​​主​​​​​​​机​​​​​​​搬​​​​​​​迁​​​​​​​到​​​​​​​另​​​​​​​外​​​​​​​一​​​​​​​台​​​​​​​主​​​​​​​机​​​​​​​。​​​​​​​红​​​​​​​帽​​​​​​​虚​​​​​​​拟​​​​​​​化​​​​​​​系​​​​​​​统​​​​​​​支​​​​​​​持​​​​​​​两​​​​​​​种​​​​​​​移​​​​​​​植​​​​​​​方​​​​​​​式​​​​​​​ — offline 和​​​​​​​ live。​​​​​​​Offline 移​​​​​​​植​​​​​​​通​​​​​​​过​​​​​​​暂​​​​​​​停​​​​​​​虚​​​​​​​拟​​​​​​​机​​​​​​​、​​​​​​​转​​​​​​​移​​​​​​​内​​​​​​​存​​​​​​​然​​​​​​​后​​​​​​​在​​​​​​​目​​​​​​​的​​​​​​​主​​​​​​​机​​​​​​​上​​​​​​​恢​​​​​​​复​​​​​​​执​​​​​​​行​​​​​​​的​​​​​​​方​​​​​​​式​​​​​​​把​​​​​​​虚​​​​​​​拟​​​​​​​机​​​​​​​从​​​​​​​一​​​​​​​台​​​​​​​主​​​​​​​机​​​​​​​移​​​​​​​到​​​​​​​另​​​​​​​外​​​​​​​一​​​​​​​台​​​​​​​主​​​​​​​机​​​​​​​。​​​​​​​Live 移​​​​​​​植​​​​​​​做​​​​​​​相​​​​​​​同​​​​​​​的​​​​​​​事​​​​​​​情​​​​​​​，但​​​​​​​不​​​​​​​直​​​​​​​接​​​​​​​影​​​​​​​响​​​​​​​域​​​​​​​。​​​​​​​当​​​​​​​执​​​​​​​行​​​​​​​ live 移​​​​​​​植​​​​​​​时​​​​​​​，域​​​​​​​继​​​​​​​续​​​​​​​它​​​​​​​平​​​​​​​常​​​​​​​的​​​​​​​活​​​​​​​动​​​​​​​，从​​​​​​​用​​​​​​​户​​​​​​​的​​​​​​​角​​​​​​​度​​​​​​​来​​​​​​​看​​​​​​​它​​​​​​​并​​​​​​​没​​​​​​​有​​​​​​​值​​​​​​​得​​​​​​​注​​​​​​​意​​​​​​​的​​​​​​​地​​​​​​​方​​​​​​​。​​​​​​​要​​​​​​​初​​​​​​​始​​​​​​​化​​​​​​​一​​​​​​​个​​​​​​​ live 移​​​​​​​植​​​​​​​，两​​​​​​​台​​​​​​​主​​​​​​​机​​​​​​​都​​​​​​​必​​​​​​​须​​​​​​​运​​​​​​​行​​​​​​​红​​​​​​​帽​​​​​​​虚​​​​​​​拟​​​​​​​化​​​​​​​系​​​​​​​统​​​​​​​以​​​​​​​及​​​​​​​ xend 守​​​​​​​护​​​​​​​进​​​​​​​程​​​​​​​。​​​​​​​目​​​​​​​的​​​​​​​主​​​​​​​机​​​​​​​必​​​​​​​须​​​​​​​有​​​​​​​足​​​​​​​够​​​​​​​的​​​​​​​资​​​​​​​源​​​​​​​（如​​​​​​​内​​​​​​​存​​​​​​​）来​​​​​​​容​​​​​​​纳​​​​​​​移​​​​​​​植​​​​​​​后​​​​​​​的​​​​​​​域​​​​​​​带​​​​​​​宽​​​​​​​（bandwidth）。​​​​​​​源​​​​​​​主​​​​​​​机​​​​​​​和​​​​​​​目​​​​​​​的​​​​​​​主​​​​​​​机​​​​​​​都​​​​​​​必​​​​​​​须​​​​​​​有​​​​​​​相​​​​​​​同​​​​​​​的​​​​​​​体​​​​​​​系​​​​​​​结​​​​​​​构​​​​​​​和​​​​​​​虚​​​​​​​拟​​​​​​​化​​​​​​​扩​​​​​​​展​​​​​​​（如​​​​​​​ i386-VT、​​​​​​​x86-64-VT、​​​​​​​x86-64-SVM 等​​​​​​​）且​​​​​​​必​​​​​​​须​​​​​​​都​​​​​​​位​​​​​​​于​​​​​​​相​​​​​​​同​​​​​​​的​​​​​​​ L2 子​​​​​​​网​​​​​​​。​​​​​​​

When a domain migrates its MAC and IP addresses move with it. Only virtual machines with the same layer-2 network and subnets will successfully migrate. If the destination node is on a different subnet, the administrator must manually configure a suitable EtherIP or IP tunnel in the remote node of domain0. The xend daemon stops the domain and copies the job over to the new node and restarts it. The Red Hat Virtualization RPM does not enable migration from any other host except the localhost (see the /etc/xend-config.sxp file for information). To allow the migration target to accept incoming migration requests from remote hosts, you must modify the target's xen-relocation-hosts-allow parameter. Be sure to carefully restrict which hosts are allowed to migrate, since there is no authentication.

既​​​​​​​然​​​​​​​这​​​​​​​些​​​​​​​域​​​​​​​涉​​​​​​​及​​​​​​​如​​​​​​​此​​​​​​​大​​​​​​​的​​​​​​​文​​​​​​​件​​​​​​​分​​​​​​​配​​​​​​​，这​​​​​​​个​​​​​​​过​​​​​​​程​​​​​​​可​​​​​​​能​​​​​​​会​​​​​​​消​​​​​​​耗​​​​​​​较​​​​​​​久​​​​​​​的​​​​​​​时​​​​​​​间​​​​​​​。​​​​​​​如​​​​​​​果​​​​​​​你​​​​​​​移​​​​​​​植​​​​​​​带​​​​​​​有​​​​​​​开​​​​​​​放​​​​​​​网​​​​​​​络​​​​​​​连​​​​​​​接​​​​​​​的​​​​​​​域​​​​​​​，这​​​​​​​些​​​​​​​连​​​​​​​接​​​​​​​将​​​​​​​在​​​​​​​目​​​​​​​的​​​​​​​主​​​​​​​机​​​​​​​上​​​​​​​保​​​​​​​留​​​​​​​，SSH 连​​​​​​​接​​​​​​​应​​​​​​​该​​​​​​​仍​​​​​​​然​​​​​​​可​​​​​​​用​​​​​​​。​​​​​​​缺​​​​​​​省​​​​​​​的​​​​​​​Red Hat虚​​​​​​​拟​​​​​​​化​​​​​​​系​​​​​​​统​​​​​​​的​​​​​​​ iptables 规​​​​​​​则​​​​​​​将​​​​​​​不​​​​​​​允​​​​​​​许​​​​​​​传​​​​​​​入​​​​​​​的​​​​​​​移​​​​​​​植​​​​​​​连​​​​​​​接​​​​​​​。​​​​​​​如​​​​​​​要​​​​​​​允​​​​​​​许​​​​​​​这​​​​​​​种​​​​​​​连​​​​​​​接​​​​​​​，你​​​​​​​必​​​​​​​须​​​​​​​创​​​​​​​建​​​​​​​显​​​​​​​性​​​​​​​的​​​​​​​ iptables 规​​​​​​​则​​​​​​​。​​​​​​​

你​​​​​​​可​​​​​​​以​​​​​​​使​​​​​​​用​​​​​​​ xm migrate 命​​​​​​​令​​​​​​​来​​​​​​​执​​​​​​​行​​​​​​​ offline 移​​​​​​​植​​​​​​​：

xm migrate domain-id [destination domain]

你​​​​​​​可​​​​​​​以​​​​​​​使​​​​​​​用​​​​​​​ xm migrate 命​​​​​​​令​​​​​​​来​​​​​​​执​​​​​​​行​​​​​​​ live 移​​​​​​​植​​​​​​​：

xm  migrate domain-id -l [destination domain]

You may need to reconnect to the domain's console on the new machine. You can use the xm console command to reconnect.