kvm常见故障及解决方案

# virsh start vmhost1error: Failed to start domain vmhost1error: Unable to read from monitor: Connection reset by peer

# virsh managedsave-remove vmhost1# virsh start vmhost1

Cannot set up guest memory 'pc.ram': Cannot allocate memory

error: Failed to define domain from hostname.xmlerror: Cannot find QEMU binary /usr/bin/kvm: No such file or directory

# ln -s /usr/libexec/qemu-kvm /usr/bin/kvm

# virsh start vmhost1  

error: Failed to start domain vmhost1error: internal error process exited while connecting to monitor: kvm: -drive file=/dev/sp1368155439693/v1368544020461,if=none,id=drive-virtio-disk0,format=qcow2: could not open disk p_w_picpath /dev/sp1368155439693/v1368544020461: Invalid argument

Unable to load library 'virt': libvirt.so: cannot open shared object file: No such file or directoryLinux下解决：      ln -s /usr/lib/libvirt.so.0   /usr/lib/libvirt.so

windows下解决：
      将libvirt-0.dll改名为virt.dll

# virsh undefine vmhost1error: Refusing to undefine while domain managed save p_w_picpath existshttp://www.redhat.com/archives/libvir-list/2011-July/msg01219.html

# /usr/local/sbin/libvirtd -d -l --config /usr/local/etc/libvirt/libvirtd.conf （编译安装的启动方式）

error：/usr/local/sbin/libvirtd: initialization failed
try to install libpcap-devel RPM and rebuild libvirt  http://comments.gmane.org/gmane.comp.emulators.libvirt/58218apt-get install libpcap-dev
上面的方法好像都没有效果，但是尝试了http://wiki.libvirt.org/page/The_daemon_cannot_be_started说的，把配置文件里的
listen_tls = 0注释取消（更奇怪的问题，在我的客户端链接不对）

# virsh start vmhost1error: Failed to start domain vmhost1error: internal error process exited while connecting to monitor: Could not access KVM kernel module: No such file or directoryfailed to initialize KVM: No such file or directoryNo accelerator found!

# modprobe kvm   #载入指定的模块

通过命令 lsmod | grep kvm    #显示已载入的模块

# virsh migrate --live 1 qemu+tcp://192.168.0.121 --p2p --tunnelled --unsafe error: operation failed: Failed to connect to remote libvirt URI qemu+tcp://192.168.0.121（在URI后面加上/system，‘system’相当于root用户的访问权限)

#virsh migrate --live 2 qemu+tcp://192.168.0.121/system --p2p --tunnelled
 error: Unsafe migration: Migration may lead to data corruption if disks use cache != none（加上--unsafe参数）#virsh migrate --live 2 qemu+tcp://192.168.0.121/system --p2p --tunnelled --unsafe error: Timed out during operation: cannot acquire state change lock (启动虚拟机有时也会遇此错误）,需要重启libvirtd进程

error: Failed to connect socket to '/var/run/libvirt/libvirt-sock': Connection refused(libvirtd 进程没有启动，libvirtd是一个监听客户端请求的进程）# virsh -c qemu:///system listerror: Failed to connect socket to '/var/run/libvirt/libvirt-sock': Permission denied
error: failed to connect to the hypervisor
（当前用户没有权限，修改/etc/libvirt/libvirtd.conf,unix_sock_rw_perms = 0777,使所有用户都有权限读写）