CentOS6에 KVM 설치하기

출처: http://itscblog.tamu.edu/startup-guide-for-kvm-on-centos-6  주의할 점은 저 같은 경우 브릿지 네트워크를 설정할 때, ifcfg-eth0에 static IP를 설정하려고 하는 실수를 하게되더군요.   아래의 네트워크 브릿징 설명대로 eth0에는 아이피를 세팅하지 않고 br0에 호스트  메인 IP를 세팅하여야 합니다. (/etc/sysconfig/network-scripts/ifcfg-br0) 출처에 가서 원본을 보기를 바라며 링크가 없어짐을 대비해 아래에 사본을 둡니다. Installing KVM ¶ If you choose the “Minimal” option during CentOS 6 then this step is necessary. To get the full set of tools there are 4 software groups to install… Virtualization Virtualization Client Virtualization Platform Virtualization Tools To install run 1 yum groupinstall "Virtualization*" dejavu-lgc-sans-fonts is necessary or all the fonts in virt-manager will show as squares 1 yum install dejavu-lgc-sans-fonts Once the install is finished verify that the KVM kernel module is loaded. 1 lsmod | grep kvm You should see either kvm_intel or kvm_amd depending  on your host’s CPU manufacturer. At this point I chose to reboot the server. This allows services to be started and udev rules for KVM to be applied. This will also allow dbus to create the machine-id file, otherwise you would see something like the below when running virt-manager 1 2 3 4 5 6 # virt-manager  Xlib:  extension "RANDR" missing  on display "localhost:10.0". process 1869: D-Bus library appears to be incorrectly set up; failed to read machine uuid: Failed to open "/var/lib/dbus/machine-id": No such file or directory See the manual page for dbus-uuidgen to correct this issue.   D-Bus not built with -rdynamic so unable to print a backtrace Aborted If you receive that D-Bus error and would prefer not to restart then run this command to generate the necessary machine-id file 1 dbus-uuidgen > /var/lib/dbus/machine-id Final configuration steps The server I run KVM  on is headless, but I still like using virt-manager. So we must install the necessary tools to do X11 forwarding through SSH. 1 2 3 4 yum install xorg-x11-xauth # If you plan to use VNC to connect to the virtual machine's console locally yum install tigervnc Now when you connect through SSH be sure to pass the -X flag to enable X11 forwarding. Optional: Using an alternate location for VM images with SELinux With SELinux enabled, special steps must be taken to change the default VM store from /var/lib/libvirt/images. My particular server I choose to keep all images and ISOs for VMs under /vmstore. The steps below give your new store the correct security context for SELinux. 1 2 3 4 5 # this package is necessary to run semanage yum install policycoreutils-python semanage fcontext -a -t virt_image_t "/vmstore(/.*)?" restorecon -R /vmstore To activate this store you must open virt-manager, select your host, then do Edit-> Host Details. Under the Storage tab you can add your new storage volume. Optional : Network Bridging for Virtual Machines If you wish for your virtual machines to be accessible remotely then you must use network bridging to share your host’s network interface with the virtual machines. The setup requires linking  one of your host’s physical interfaces with a bridge device. First copy your physical interface’s ifcfg file to create the new bridge device, named br0. 1 cp /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-br0 Modify ifcfg-br0 to have the IP information in ifcfg-eth0 and remove, or comment out, that information in ifcfg-eth0. Below are examples of ifcfg-eth0 and ifcfg-br0. The highlighted lines are important. /etc/sysconfig/network-scripts/ifcfg-eth0 1 2 3 4 DEVICE=eth0 HWADDR=00:18:8B:58:07:3B ONBOOT=yes BRIDGE=br0 /etc/sysconfig/network-scripts/ifcfg-br0 1 2 3 4 5 6 DEVICE=br0 TYPE=Bridge BOOTPROTO=static ONBOOT=yes IPADDR=10.1.0.3 NETMASK=255.255.255.0 Once those two files are configured restart the network service 1 service network restart Optional: Managing libvirt with standard user account Beginning in CentOS 6 access to managing libvirt is handled by PolicyKit. It’s always a good practice to do your daily administration tasks as some user besides root, and using PolicyKit you can give access to libvirt functions to a standard account. First we create the necessary config file to define the access controls. The file must begin with a numeric value and have the .pkla extension. 1 vim /etc/polkit-1/localauthority/50-local.d/50-libvirt-remote-access.pkla Here’s an example of the file I used to give access to a single user. Be sure to put your desired username in place of username  on the highlighted line. 1 2 3 4 5 6 [libvirt Management Access] Identity=unix-user:username Action=org.libvirt.unix.manage ResultAny=yes ResultInactive=yes ResultActive=yes You can optionally replace Identity=unix-user:username with Identity=unix-group:groupname to allow access to a group of users. Finally restart the libvirtd daemon to apply your changes. 1 /etc/init.d/libvirtd restart Creating the first virtual machine You are now ready to create your virtual machines. Create the virtual disk With the version of virt-manager shipped with CentOS 6 you cannot create qcow2 images from within the GUI. If you wish to create your new VM with a qcow2 format virtual disk you must do so from the command line, or see the next section for RPMs to upgrade virt-manager. Update: Through some testing I’ve found that performance can be greatly improved if the preallocation is set when creating a qcow2 image. See my recent post at Improve disk I/O performance in KVMfor more information  on improving performance in KVM. 1 2 3 4 5 # With preallocation qemu-img create -f qcow2 -o preallocation=metadata CentOS-6.0-x86_64-Template.qcow2 20G # Without preallocation qemu-img create -f qcow2 CentOS-6.0-x86_64-Template.qcow2 20G NOTE: Replace the filename “CentOS-6.0-x86_64-Template” with your desired name, and also replace “20G” with the desired max size of the virtual disk. Now when creating your virtual machine select to use an existing virtual disk. virt-manager-0.8.7 See my blog post virt-manager 0.8.7 for CentOS 6 Updated to get RPMs to upgrade the version of virt-manager that comes with CentOS 6. With this version you can change / specify the virtual disk format from within the GUI.

[CentOS] vmware이미지를 QEMU/Xen이미지로 변경 Admin 출처: http://unixfoo.blogspot.com/2008/12/vmware-to-xen-conversion.html         http://www.mytechdocs.com/convert-vmware-vm-to-kvmxenqemu/ 기존에 사용하던 vmware이미지를 QEMU/Xen이미지로 변경하는 법 1) Delete any old Snapshots. 2) Halt the vmware VM . Check the format of the vmware vmdk file # qemu-img info mtdhost-xp.vmdk image: mtdhost-xp.vmdk file format: raw virtual size: 15G disk size: 15G 3) If the file format is “raw”, we need not convert the image file using qemu-img convert, just rename to .img file. If it is not “raw”, use “qemu-img” to convert the image to raw format. Otherwise skip step 4. 4) How to convert using qemu-img. # qemu-img convert mtdhost-xp.vmdk -O raw /VM/mtdhost-xp.img 5) Create xen config file in /etc/xen/mtdhost-xp (or use the virt-manager utility and choose the newly converted file as the harddrive image), with the renamed/converted image file as disk. disk = [ 'file:/VM/mtdhost-xp.img,hda,w' ] 6) Boot up the xen domU guest. It should boot up fine.

네트워크 설정 후, network restart할 때 에러가 난다면.... Admin 브릿지 설정 후 재부팅하면 최초부팅 시에만 되고 네트웤을 재시작하면  master connection not found와 같은 에러가 발생되어 IP가 올라오지 않는 현상이  특정 서버에서 발견되었다. NetworkManager 데몬이 너무 친절해서 간섭하여 발생되는 에러이므로 내리고 재시작하자. service NetworkManager stop service network restart chkconfig로 아예 부팅시 실행이 안되게 설정해두는 것도 좋다. http://hwangji.kr/sub/dev_leader/link/os/default.aspx?NHBBSID=NHBoardWebTip&NHBBSIDX=62 출처 : http://cafe.naver.com/linuxlog/2518