| 89 | | There are 2 possibilities to select the OS version used by a cluster or a specific node : |
| 90 | | |
| 91 | | * Define the OS version at the cluster level : this is done by adding the appropriate path in {{{cluster.build.properties}}}. Look at the example above, in section [[wiki:Doc/TemplateCustom#ClustersandTemplateHierarchies Clusters and Template Hierarchies]]. Using this method, all the machines in the cluster MUST run the same OS version/architecture. This is the only method available for SL versions before SL 3.07 or SL 4.2. Using this method allows to define a default OS version for the cluster. |
| 92 | | * Define the OS version at the machine level : this is done by creating a template `pro_os_version_db.tpl` in your site or cluster hierarchy. In this template, variable `OS_VERSION` must contain one entry for each machine that is not using the default OS version defined for the cluster. The value is the directory containing templates for the OS version. This method allows to have different version/architecture combination into the same cluster. This second method requires OS template path in {{{cluster.build.properties}}} to be defined as {{{os}}} instead of the hierarchy used in first method. |
| 93 | | |
| 94 | | An example of `pro_os_version_db.tpl` template can be found in the [browser/templates/trunk/sites/example/site/pro_os_version_db_lcg.tpl examples] provided in the repository. If you want to use another name for this template, you need to define variable NODE_OS_VERSION_DB in cluster `pro_site_cluster_info.tpl` template or in site `pro_site_global_variables.tpl` template. Look at [browser/templates/trunk/clusters/example/site/pro_site_cluster_info.tpl examples] provided with QWG template releases. |
| 95 | | |
| 96 | | Both methods can also be combined by specifying OS template path as follow in {{{cluster.build.properties}}} : |
| 97 | | {{{ |
| 98 | | os os/sl307-i386 |
| 99 | | }}} |
| 100 | | |
| 101 | | With these entries, the cluster will use SL 3.07 i386 as the default OS version for the cluster but this is possible to override this in any machine templates, using the second method. This is the only possibility to have both SL3 and SL4 in the same cluster, as SL3 templates don't support the second method. |
| 102 | | |
| 103 | | |
| 104 | | === Selecting Kernel Version === |
| 105 | | |
| 106 | | Normally, standard templates provide an appropriate definition of the kernel number and variant (smp, hugemem...) according to hardware present (as declared in templates). If you want to override this default (used in particular to configure Grub), you can use the following variables : |
| 107 | | |
| 108 | | * `KERNEL_VERSION_NUM` : this must contain the kernel version, as it is in the RPM name, without the architecture. |
| 109 | | * `KERNEL_VARIANT` : `smp`, `hugemem`, `largesmp`... or nothing (empty string) for non smp kernel. |
| | 89 | Refer to page on [wiki:Doc/OSTemplates Configuring OS]. |
