Show Table of Contents Hide Table of Contents English Español 한국어 日本語 Italiano Deutsch 繁體中文 简体中文 Français Português Русский English Multi-page HTML Single-page HTML PDF ePub Virtualization GuidePreface1. About this book1.1. Overview2. What is Virtualization?3. Types of Virtualization3.1. Full Virtualization3.2. Para-Virtualization3.3. Para-virtualized drivers4. How CIOs should think about virtualizationI. Requirements and Limitations for Virtualization with Red Hat Enterprise Linux1. System requirements2. Xen restrictions and support3. KVM restrictions and support4. Hyper-V restrictions and support4.1. Hyper-V drivers5. Virtualization limitations5.1. General limitations for virtualization5.2. KVM limitations5.3. Xen limitations5.4. Application limitationsII. Installation6. Installing the virtualization packages6.1. Installing Xen with a new Red Hat Enterprise Linux installation6.2. Installing Xen packages on an existing Red Hat Enterprise Linux system6.3. Installing KVM with a new Red Hat Enterprise Linux installation6.4. Installing KVM packages on an existing Red Hat Enterprise Linux system7. Guest installation overview7.1. Creating guests with virt-install7.2. Creating guests with virt-manager7.3. Installing guests with PXE8. Guest operating system installation procedures8.1. Installing Red Hat Enterprise Linux 5 as a para-virtualized guest8.2. Installing Red Hat Enterprise Linux as a fully virtualized guest8.3. Installing Windows XP as a fully virtualized guest8.4. Installing Windows Server 2003 as a fully virtualized guest8.5. Installing Windows Server 2008 as a fully virtualized guestIII. Configuration9. Virtualized storage devices9.1. Creating a virtualized floppy disk controller9.2. Adding storage devices to guests9.3. Configuring persistent storage in Red Hat Enterprise Linux 59.4. Add a virtualized CD-ROM or DVD device to a guest10. Network Configuration10.1. Network Address Translation (NAT) with libvirt10.2. Bridged networking with libvirt11. Pre-Red Hat Enterprise Linux 5.4 Xen networking11.1. Configuring multiple guest network bridges to use multiple Ethernet cards11.2. Red Hat Enterprise Linux 5.0 laptop network configuration12. Xen Para-virtualized Drivers12.1. System requirements12.2. Para-virtualization Restrictions and Support12.3. Installing the Para-virtualized Drivers12.3.1. Common installation steps12.3.2. Installation and Configuration of Para-virtualized Drivers on Red Hat Enterprise Linux 312.3.3. Installation and Configuration of Para-virtualized Drivers on Red Hat Enterprise Linux 412.3.4. Xen Para-virtualized Drivers on Red Hat Enterprise Linux 512.3.5. Xen Para-virtualized Drivers on Red Hat Enterprise Linux 612.4. Para-virtualized Network Driver Configuration12.5. Additional Para-virtualized Hardware Configuration12.5.1. Virtualized Network Interfaces12.5.2. Virtual Storage Devices13. KVM Para-virtualized Drivers13.1. Installing the KVM Windows para-virtualized drivers13.2. Installing drivers with a virtualized floppy disk13.3. Using KVM para-virtualized drivers for existing devices13.4. Using KVM para-virtualized drivers for new devices14. Installing Red Hat Enterprise Linux 6 as a Xen guest on Red Hat Enterprise Linux 514.1. Installing Red Hat Enterprise Linux 6 as a Xen para-virtualized guest on Red Hat Enterprise Linux 514.1.1. Using virt-install14.1.2. Using virt-manager14.2. Installing Red Hat Enterprise Linux 6 as a Xen fully virtualized guest on Red Hat Enterprise Linux 515. PCI passthrough15.1. Adding a PCI device with virsh15.2. Adding a PCI device with virt-manager15.3. PCI passthrough with virt-install15.4. Removing a PCI passthrough device for host re-use15.5. PCI passthrough for para-virtualized Xen guests on Red Hat Enterprise Linux16. SR-IOV16.1. Introduction16.2. Using SR-IOV16.3. Troubleshooting SR-IOV17. KVM guest timing managementIV. Administration18. Server best practices19. Security for virtualization19.1. Storage security issues19.2. SELinux and virtualization19.3. SELinux19.4. Virtualization firewall information20. Managing guests with xend21. Xen live migration21.1. A live migration example21.2. Configuring guest live migration22. KVM live migration22.1. Live migration requirements22.2. Share storage example: NFS for a simple migration22.3. Live KVM migration with virsh22.4. Migrating with virt-manager23. Remote management of guests23.1. Remote management with SSH23.2. Remote management over TLS and SSL23.3. Transport modesV. Virtualization Storage Topics24. Using shared storage with virtual disk images24.1. Using iSCSI for storing virtual disk images24.1.1. How to set up an iSCSI target on Red Hat Enterprise Linux24.1.2. How to configure iSCSI on a libvirt KVM host and provision a guest using virt-installVI. Virtualization Reference Guide25. Virtualization tools26. Managing guests with virsh27. Managing guests with the Virtual Machine Manager (virt-manager)27.1. The Add Connection window27.2. The Virtual Machine Manager main window27.3. The guest Overview tab27.4. Virtual Machine graphical console 27.5. Starting virt-manager27.6. Restoring a saved machine 27.7. Displaying guest details27.8. Status monitoring27.9. Displaying guest identifiers27.10. Displaying a guest's status 27.11. Displaying virtual CPUs 27.12. Displaying CPU usage27.13. Displaying memory usage 27.14. Managing a virtual network27.15. Creating a virtual network28. The xm command quick reference29. Configuring the Xen kernel boot parameters30. Configuring ELILO31. libvirt configuration reference32. Xen configuration filesVII. Tips and Tricks33. Tips and tricks33.1. Automatically starting guests33.2. Changing between the KVM and Xen hypervisors33.2.1. Xen to KVM33.2.2. KVM to Xen33.3. Using qemu-img33.4. Overcommitting Resources33.5. Modifying /etc/grub.conf33.6. Verifying virtualization extensions33.7. Accessing data from a guest disk image33.8. Setting KVM processor affinities33.9. Generating a new unique MAC address33.10. Limit network bandwidth for a Xen guest33.11. Configuring Xen processor affinities33.12. Modifying the Xen hypervisor33.13. Very Secure ftpd 33.14. Configuring LUN Persistence33.15. Disable SMART disk monitoring for guests33.16. Cleaning up old Xen configuration files33.17. Configuring a VNC Server33.18. Cloning guest configuration files33.19. Duplicating an existing guest and its configuration file34. Creating custom libvirt scripts34.1. Using XML configuration files with virshVIII. Troubleshooting35. Troubleshooting Xen35.1. Debugging and troubleshooting Xen35.2. Log files overview35.3. Log file descriptions35.4. Important directory locations35.5. Troubleshooting with the logs35.6. Troubleshooting with the serial console35.7. Para-virtualized guest console access35.8. Fully virtualized guest console access35.9. Common Xen problems35.10. Guest creation errors35.11. Troubleshooting with serial consoles35.11.1. Serial console output for Xen35.11.2. Xen serial console output from para-virtualized guests35.11.3. Serial console output from fully virtualized guests35.12. Xen configuration files35.13. Interpreting Xen error messages35.14. The layout of the log directories36. Troubleshooting36.1. Identifying available storage and partitions36.2. After rebooting Xen-based guests the console freezes36.3. Virtualized Ethernet devices are not found by networking tools36.4. Loop device errors36.5. Failed domain creation caused by a memory shortage36.6. Wrong kernel image error36.7. Wrong kernel image error - non-PAE kernel on a PAE platform36.8. Fully-virtualized 64 bit guest fails to boot36.9. A missing localhost entry causes virt-manager to fail36.10. Microcode error during guest boot36.11. Python depreciation warning messages when starting a virtual machine36.12. Enabling Intel VT and AMD-V virtualization hardware extensions in BIOS36.13. KVM networking performance37. Troubleshooting the Xen para-virtualized drivers37.1. Red Hat Enterprise Linux 5 Virtualization log file and directories37.2. Para-virtualized guest fail to load on a Red Hat Enterprise Linux 3 guest operating system37.3. A warning message is displayed while installing the para-virtualized drivers on Red Hat Enterprise Linux 337.4. Manually loading the para-virtualized drivers37.5. Verifying the para-virtualized drivers have successfully loaded37.6. The system has limited throughput with para-virtualized driversA. Additional resourcesA.1. Online resourcesA.2. Installed documentationB. ColophonLegal Notice 36.2. After rebooting Xen-based guests the console freezes Occasionally, a Xen guest's console freezes when the guest boots. The console still displays messages but the user cannot log in. To fix this issue add the following line to the /etc/inittab file: 1:12345:respawn:/sbin/mingetty xvc0 After saving the file, reboot. The console session should now be interactive as expected. 36.1. Identifying available storage and partitions 36.3. Virtualized Ethernet devices are not found by networking tools Where did the comment section go?Red Hat's documentation publication system recently went through an upgrade to enable speedier, more mobile-friendly content. We decided to re-evaluate our commenting platform to ensure that it meets your expectations and serves as an optimal feedback mechanism. During this redesign, we invite your input on providing feedback on Red Hat documentation via the discussion platform.