我在戴尔服务器上使用 kvm 和 libvirt。现在我试图将一台虚拟机从一台物理服务器迁移到另一台物理服务器。但是每次都失败了。
在 physicalServer1 上的 virsh 中，我输入：
virsh # migrate virtualmachine1 qemu+ssh://username@physicalServer2/system
error: operation failed: migration to 'tcp:physicalServer2:49163' failed: migration failed
然后我搜索了libvirt.org 上的常见问题解答部分。 它说：
error: operation failed: migration to '...' failed: migration failed
This is an error often encountered when trying to migrate with QEMU/KVM. This typically happens with plain migration, when the source VM cannot connect to the destination host. You will want to make sure your hosts are properly configured for migration (see the migration section of this FAQ)
我设法ssh physicalServer2从 virtualmachine1 上的 shell 中获取信息，因此上面的红色部分并不能解释我的失败。
我也在physicalServer2上打开端口，iptables -L显示以下信息：
Chain INPUT (policy ACCEPT)
target prot opt source destination
ACCEPT udp -- anywhere anywhere udp dpt:domain
ACCEPT tcp -- anywhere anywhere tcp dpt:domain
ACCEPT udp -- anywhere anywhere udp dpt:bootps
ACCEPT tcp -- anywhere anywhere tcp dpt:bootps
ACCEPT udp -- anywhere anywhere udp dpt:domain
ACCEPT tcp -- anywhere anywhere tcp dpt:domain
ACCEPT udp -- anywhere anywhere udp dpt:bootps
ACCEPT tcp -- anywhere anywhere tcp dpt:bootps
ACCEPT tcp -- anywhere anywhere state NEW tcp dpts:49152:49215
Chain FORWARD (policy ACCEPT)
target prot opt source destination
ACCEPT all -- anywhere 192.168.122.0/24 state RELATED,ESTABLISHED
ACCEPT all -- 192.168.122.0/24 anywhere
ACCEPT all -- anywhere anywhere
REJECT all -- anywhere anywhere reject-with icmp-port-unreachable
REJECT all -- anywhere anywhere reject-with icmp-port-unreachable
ACCEPT all -- anywhere 192.168.122.0/24 state RELATED,ESTABLISHED
ACCEPT all -- 192.168.122.0/24 anywhere
ACCEPT all -- anywhere anywhere
REJECT all -- anywhere anywhere reject-with icmp-port-unreachable
REJECT all -- anywhere anywhere reject-with icmp-port-unreachable
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
physicalServer2 上的 /var/log/libvirt/qemu/virtualmachine1.log：
2011-05-06 13:37:30.708: starting up
LC_ALL=C PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/sbin:/sbin:/bin QEMU_AUDIO_DRV=none /usr/bin/kvm -S -M pc-0.14 -enable-kvm -m 2048 -smp 1,sockets=1,cores=1,threads=1 -name openjudge-test -uuid a8c704bc-a4f9-90db-3e57-40e60b00aac1 -nodefconfig -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/virtualmachine1.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=readline -rtc base=utc -boot c -drive file=/media/nfs/virtualmachine1.img,if=none,id=drive-ide0-0-0,format=raw -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 -drive if=none,media=cdrom,id=drive-ide0-1-0,readonly=on,format=raw -device ide-drive,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0 -netdev tap,fd=20,id=hostnet0 -device rtl8139,netdev=hostnet0,id=net0,mac=00:16:36:8a:22 :a0,bus=pci.0,addr=0x3 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -usb -vnc 127.0.0.1:2 -vga cirrus -incoming tcp:0.0.0.0:49163 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4
char device redirected to /dev/pts/0
2011-05-06 13:37:30.915: shutting down
physicalServer1 上的 /var/log/libvirt/qemu/virtualmachine1.log 是空的。
两台物理服务器均使用Ubuntu 11.04，使用的libvirt和kvm都是通过apt-get安装的，libvirt版本是0.8.8。
答案1
确保在主机之间打开 TCP 49152-49261，并在 DNS 或彼此的 /etc/hosts 文件中为每个主机名打开 TCP 49152-49261。出于某种原因，KVM 迁移是根据主机名而不是 IP 地址进行的。
答案2
确保两台主机服务器位于同一个物理交换机（或 VLAN）上。