Changes between Version 8 and Version 9 of Doc/OS/Customization

Timestamp:

Aug 28, 2009, 10:51:42 PM (16 years ago)

Author:

/O=GRID-FR/C=FR/O=CNRS/OU=LAL/CN=Michel Jouvin

Comment:

--

Doc/OS/Customization

@@ -30 +30 @@
 == Selecting Kernel Version ==
 
-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, you can use the following variables :
+Normally, standard templates provide an appropriate definition of the kernel number and variant (smp, hugemem...) according to OS version used and the hardware present (as declared in templates). If you want to override this default, you can use the following variables (typically at the very beginning of the node profile or in cluster `site/cluster_info.tpl`) :
 
  * `KERNEL_VERSION_NUM` : this must contain the kernel version, as it is in the RPM name, without the architecture.
@@ -37 +37 @@
 Proper definition of these variables is important. They are used both to select RPMs to install for kernel and kernel modules and to configure Grub.
 
-''Note : only one version of RPMs for kernel and kernel module are present at anytime in the configuration. Be cautious when changing one of these variables on an already installed machine as it will uninstall previously used version. This will change in the future when SPMA will be able to keep the previously installed version, even if no longer part of the configuration. Grub cannot be configured to use a kernel version other than the one present in the node profile.''
+Defining `KERNEL_VERSION_NUM` directly may not be convenient if you want to define it for a large number of machines but not all in your cluster because if you define it in the node profile, this involves editing a large number of templates and if you define it at the cluster level, it may not work if all the machines don't use the same OS version. An alternative to defining this variable directly is to define the variable `OS_KERNEL_VERSION`. This variable is a nlist with one entry per OS version where:
+ * Key is the OS version+architecture as used to define the OS used by the machine (e.g. `sl470-x86_64`) or the OS version without the architecture (e.g. `sl470`) in which case the kernel version will be used for all architectures of this OS version.
+ * Value is a string corresponding to the kernel RPM version.
+ 
+The variable `OS_KERNEL_VERSION` must typically be defined in the template defining the OS version for each machine (the template pointed by variable `NODE_OS_VERSION_DB`).
+
+''Note : only one version of RPMs for kernel and kernel module are present at anytime in the configuration. Be cautious when changing one of these variables on an already installed machine as it will uninstall the previously used version. This will change in the future when SPMA will be able to keep the previously installed version, even if no longer part of the configuration. Grub cannot be configured to use a kernel version other than the one present in the node profile, thus rebooting with an old kernel may require an interactive boot to reconfigure Grub.''
 
 == Selecting Kernel Architecture ==