Changes between Version 7 and Version 8 of Doc/OS/Xen


Ignore:
Timestamp:
Feb 11, 2008, 1:48:51 PM (18 years ago)
Author:
/C=IE/O=Grid-Ireland/OU=cs.tcd.ie/L=RA-TCD/CN=Stephen O. Childs
Comment:

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  • Doc/OS/Xen

    v7 v8  
    88    * Guest VMs are installed on virtual "hardware" described in its own hardware template. For example, MAC addresses, disk sizes and names, CPU architecture, etc. can all be specified in the VMs hardware template, and will then be used to generate appropriate configuration files for guest VMs.
    99
    10 The following combinations of Xen hosts and guests should work:
     10The current checked-in templates support 64-bit SL 4.5. However, the following combinations of Xen hosts and guests can be made to work:
    1111
    1212|| '''Host OS'''  || '''Host Xen''' || '''Guest OS'''          || '''Comments''' ||
    1313|| slc450-i386    ||    3.0.3       || sl308-i386, slc450-i386 || Scientific Linux Cern used here rather than plain SL as profiles already available in QWG. ||
    1414|| sl450-x86_64   ||    3.0.3       || sl450-x86_64            || Xen guest disk is now xvda not sda (see [https://twiki.cern.ch/twiki/bin/view/LinuxSupport/UpdatingFromSLC44toSLC45 here]) ||
     15
     16Example templates are available at {{{cfg/clusters/example-xen}}}.
     17
     18= Templates =
     19The templates include both platform-specific and non-platform specific files.
     20
     21== Non-platform-specific ==
     22This is the basic Xen configuration and is found at {{{standard/xen/host}}}.
     23
     24== Platform-specific ==
     25This contains configuration specific to a particular platform (RPM lists and guest AII configuration).
    1526
    1627= Install server configuration =
    … …  
    2738There are two components to the configuration of a Xen host: the configuration of the host's own software and the creation of Xen configuration files for the guests. The template {{{xen/host/config}}} includes the template {{{xen/configure_guests}}} which will configure a set of guests in a pre-defined way according to the contents of their hardware templates. This means:
    2839 * The disk size defined in the hardware template will be use to create backing storage for the VM filesystem.
    29 
    30 
    3140 * Make sure the OS defined for your VM is correct. Check the Quattor template {{{os_version_db.tpl}}} and edit it if necessary to ensure that your host has the correct OS selected.
    3241 * Define the variable XEN_GUESTS to be a list of the guests you want to install on the host, using the names of their templates. (N.B. there is currently a restriction that the host and guest templates must be in the same cluster.) For example:
    … …  
    3847
    3948|| '''Variable''' || '''Default value''' || '''Comments''' ||
    40 || XEN_BOOT_DEVICE || "/dev/sda2" || Root filesystem of guests ||
    41 || XEN_DOM0_MEM    || "400M"      || Memory assigned to Xen Domain 0 ||
     49|| XEN_BOOT_DEVICE || "/dev/sda2" || Root filesystem of guests (not currently used as we use bootloaders for guests) ||
     50|| XEN_DOM0_MEM    || "400M"      || Memory assigned to Xen Domain 0 (added to grub entry) ||
    4251|| XEN_VG          || "vg01"      || Base volume group to create guest VM FS on ||
    43 || XEN_GUESTS      || None        || A list of FQDNs for guest VMs (e.g. list("gridgate.cs.tcd.ie", "gridui.cs.tcd.ie")) ||
     52|| XEN_GUESTS      || None        || A list of FQDNs for guest VMs (e.g. list("xen-guest.example.org")) ||
    4453|| XEN_BOOTLOADER_DEFAULT || "/usr/bin/pypxeboot" || Default bootloader for VMs. Change this to e.g. pygrub if no DHCP server is available ||
    45 || XEN_BOOTLOADER || || nlist mapping VM names to bootloader to override default, e.g. nlist("gridgt4.cs.tcd.ie","/usr/bin/pypxeboot") ||
     54|| XEN_BOOTLOADER || || nlist mapping VM names to bootloader to override default, e.g. nlist("xen-guest.example.org","/usr/bin/pypxeboot") ||
    4655|| XEN_BOOTARG_DEFAULT || "" || "vif[0]" argument needed by pypxeboot will be added automatically if using it, set to "" for pygrub ||
    4756|| XEN_BOOTARGS ||  || nlist specifying special bootargs for individual VMs ||
    … …  
    7281
    7382 * Guest VMs shouldn't use LVM for their filesystems as it just adds needless complexity.
     83 * You may encounter problems with DHCP when guests reboot with the default Xen packages. I have a patched version that works better -- I will try and rebuild for x86_64.