Changes between Version 16 and Version 17 of Obsolete/Doc/OS/Errata


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Timestamp:
Dec 17, 2009, 7:41:38 PM (14 years ago)
Author:
/O=GRID-FR/C=FR/O=CNRS/OU=LAL/CN=Michel Jouvin
Comment:

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  • Obsolete/Doc/OS/Errata

    v16 v17  
    9292=== Errata and profile cloning ===
    9393
    94 Profile cloning, also know as ''dummy WN'', is a technique that allows to configure a reference profile and then reuse it for multiple nodes, with a few customizations (it is currently used only for gLite WN, thus its name). The other nodes clone the reference profile rather than reexecuting the configuration. As a result, any modification to the reference profile is also applied to all other nodes that clone it.
     94[/wiki/Doc/gLite/WNCloning Profile cloning], also know, as ''dummy WN'', is a technique that allows to configure a reference profile and then reuse it for multiple nodes, with a few customizations (it is currently used only for gLite WN, thus its name). The other nodes clone the reference profile rather than executing the configuration. As a result, any modification to the reference profile is also applied to all other nodes that clone it.
    9595
    96 When deploying OS errata, it is not always convenient to deploy them on all nodes at once. In this case, during the errata deployment, you need to temporarily disable profile cloning on the nodes you don't want to upgrade at the same time as the reference profile. This can be done by defining variable `USE_DUMMY` to `false` in the profile of the nodes you don't want to clone temporarily. But this can be a significant amount of work if you have many profiles to modify. An alternative is to use variable `WN_DUMMY_DISABLED` which is an nlist where:
    97  * The key is the string following `PROFILE_PREFIX` in the profile name. The string must be escaped.
     96When deploying OS errata, it is not always convenient to deploy them on all nodes at once. In this case, during the errata deployment, you need to temporarily disable profile cloning on the nodes you don't want to upgrade at the same time as the reference profile. This can be achieved without modifying the profiles themselves, by defining variable `PROFILE_CLONING_DISABLED` which is an nlist where:
     97 * The key is the string following `PROFILE_PREFIX` in the profile template name.
    9898 * The value must be  `true` in order to desactive profile cloning.
    9999
    100 `WN_DUMMY_DISABLED` must be defined very early in the configuration. This is typically done at the same place where you configure profile cloning.
     100`PROFILE_CLONING_DISABLED` must be defined very early in the configuration. This is typically done at the same place where you configure profile cloning. See profile cloning [/wiki/Doc/gLite/WNCloning documentation] for more information.
    101101
    102 ''Note: it is not necessary to define the variable in the template itself, it is sometimes easier to have a separate template included by the template configuring profile cloning.''
    103