Updating document for "chain"

docs/source/advanced/chain/chain_table.rst

@@ -1,9 +1,14 @@
-Understand chain table
-======================
+Understanding chain table
+=========================
 
-The **chain** table is designed to store the tasks(For example: 'runcmd=bmcsetup', 'runimage=<URL>', 'osimage=<image name>', 'install', 'boot', 'shell', 'standby' ...). There are three related attributes **currstate**,**currchain** and **chain** in the chain table which are used to perform the **chain** mechanism.
+The chain table (``tabdump chain``) is an xCAT database table that holds the chain configuration. The following attributes can be defined to perform the chain function: ::
 
-When genesis is running on the node, it will sends 'get_task/get_next_task' request to xcatd. Then, xcatd will first copies the **chain** attribute to the **currchain** attribute, then pops one task from the **currchain** attribute and puts it into the **currstate** attribute. The **currstate** attribute will be send back to the node as the current task. The **currstate** attribute always shows the current task that is running.
+ * currstate
+ * currchain
+ * chain
 
-The pop function will continue if another 'get_next_task' request got by xCAT. It will continue until all tasks in the **currchain** attribute are completed (removed) then a 'standby' task will be send back. Then the node will standby for random time and send out 'get_task' again. It will keep in standby state until there is new task assign in ``chain`` for the node.
+To know how are those three attributes used, pls reference the picture: 
+
+.. image:: chain_tasks_logic.png 
+ 
 

docs/source/advanced/chain/chain_tasks.rst

@@ -3,38 +3,43 @@ Task Type
 
 xCAT supports following types of task which could be set in the chain:
 
-* runcmd::
+* runcmd ::
 
     runcmd=<cmd>
 
 Currently only the ``bmcsetup`` command is officially supplied by xCAT to run to configure the bmc of the compute node. You can find the ``bmcsetup`` in /opt/xcat/share/xcat/netboot/genesis/<arch>/fs/bin/. You also could create your command in this directory and adding it to be run by ``runcmd=<you cmd>``. ::
 
-    e.g. runcmd=bmcsetup
+    runcmd=bmcsetup
 
 **Note**: the command ``mknb <arch>`` is needed before reboot the node.
 
-* runimage::
+* runimage ::
 
-   runimage=<URL>
+    runimage=<URL>
 
 **URL** is a string which can be run by ``wget`` to download the image from the URL. The example could be: ::
   
-    runimage=http://$MASTER/<dir>/image.tgz
+    runimage=http://<IP of xCAT Management Node>/<dir>/image.tgz
 
-The image.tgz should can be uncompressed by ``tar xvf image.tgz``. And image.tgz should include a file named ``runme.sh`` which is a script to initiate the running of the image. Pls reference :ref:`creating image for runimage <create_image_for_runimage>` for more information about creating your own ``image``. 
+The ``image.tgz`` **must** have the following properties:
+  * Created using the ``tar zcvf`` command
+  * The tarball must include a ``runme.sh`` script to initiate the execution of the runimage
 
-**Note**: You could try to run ``wget http://$MASTER/<dir>/image.tgz`` manually to make sure the path has been set correctly.
+To create your own image, please reference :ref:`creating image for runimage <create_image_for_runimage>`. 
 
-* osimage::
+**Tip**: You could try to run ``wget http://<IP of xCAT Management Node>/<dir>/image.tgz`` manually to make sure the path has been set correctly.
+
+* osimage ::
 
    osimage=<image name>
 
-This task is used to specify that the compute node should run the OS deployment with osimage=<image name>.
+This task is used to specify the image that should be deployed onto the compute node.
 
 * shell
 
-Make the genesis gets into the shell for admin to log in and run command.
+Causes the genesis kernel to create a shell for the administrator to log in and execute commands.
 
 * standby
 
-Make the genesis gets into standby and waiting for the task from chain. If the compute node gets into this state, any new task set to chain.currstate will be run immediately.
+Causes the genesis kernel to go into standby and wait for tasks from the chain. ... 
+

docs/source/advanced/chain/create_image_for_runimage.rst

@@ -18,22 +18,25 @@ How to prepare a image for ``runimage`` in ``chain``
 
     * Create the directory for the image: ::
 
-      #mkdir -p /install/my_image
+        mkdir -p /install/my_image
 
     * Go to the direcotry and copy the rpm file into it: ::
 
-      #cd /install/my_image
-      #cp /tmp/a.rpm /install/my_image
+        cd /install/my_image
+        cp /tmp/a.rpm /install/my_image
 
     * Write the runme.sh script and modify the permission: ::
 
-       #cat runme.sh
-       echo "start installing a.rpm"
-       rpm -ivh a.rpm  
-       #chmod +x runme.sh
+         cat runme.sh
+         echo "start installing a.rpm"
+         rpm -ivh a.rpm  
+
+    * modify the runme.sh script permission: ::
+
+         chmod +x runme.sh
 
     * Create the tar ball for the directory: ::
 
-      #tar -zcvf my_image.tar .
+         tar -zcvf my_image.tgz .
 
 

docs/source/advanced/chain/index.rst

@@ -1,7 +1,7 @@
 Chain
 =====
 
-In xCAT, we introduced the **chain** mechanism which means a series of tasks that had been defined in it can be done one by one on the specified node.
+The **chain** mechanism is created to allow the administrator to define a series of tasks or operations that will be executed in series on the target node.
 
 The **chain** mechanism is implemented in xCAT genesis system. The genesis is a customized Linux system, if can be used to do discovery and configuration after booted on the specified node.
 

docs/source/advanced/chain/run_tasks_during_discovery.rst

@@ -1,9 +1,9 @@
 Run Task List During Discovery
 ==============================
 
-If you want to run a list of tasks during the discovery, set the tasks in the chain table by using the chdef command to change the chain attribute, before powering on the nodes. For example: ::
+To run a list of tasks during the discovery, set the tasks in the chain table by using the ``chdef`` command to change the chain attribute, before powering on the nodes. For example: ::
 
-    chdef <node range> chain='runcmd=bmcsetup,osimage=<osimage name>'
+    chdef <noderange> chain='runcmd=bmcsetup,osimage=<osimage name>'
 
 These tasks will be run after the discovery.
 

docs/source/advanced/chain/run_tasks_to_configure.rst

@@ -1,12 +1,11 @@
 Run Task List to Configure a Node
 =================================
 
-Run the ``nodeset`` command to set the tasks for the compute node and ``rpower <node> reset`` to initiate the running of tasks. ::
+Run the ``nodeset`` command to set the tasks for the compute node and ``rpower <noderange> reset`` to initiate the running of tasks. ::
 
-    nodeset $node runimage=http://$MASTER/image.tgz,osimage=<image_name>
-    rpower $node reset
+    nodeset <noderange> runimage=http://<IP of xCAT Management Node>/image.tgz,osimage=<image_name>
+    rpower <noderange> reset
 
 In this example, the ``runimage`` will be run first, and then the image <image_name> will be deployed to the node.
 
-During ``nodeset`` your request is put into the ``currstate`` attribute. The ``chain`` attribute is not used. The task in the ``currstate`` attribute will be passed to genesis and executed. If additional tasks are defined in the ``currchain`` attribute, these tasks will be run after the tasks in the ``currstate`` attribute are run.
 

docs/source/advanced/index.rst

@@ -4,20 +4,20 @@ Advanced Topics
 .. toctree::
    :maxdepth: 2
 
-   confluent/index.rst
-   cluster_maintenance/index.rst
    chain/index.rst
+   cluster_maintenance/index.rst
+   confluent/index.rst
    docker/index.rst
    gpu/index.rst
    hamn/index.rst
    hierarchy/index.rst
+   kit/index.rst
    mixed_cluster/index.rst
    networks/index.rst
    ports/xcat_ports.rst
    raid/index.rst
    security/index.rst
    softlayer/index.rst
-   kit/index.rst
    switches/index.rst
    sysclone/index.rst
    webservices/index.rst

docs/source/guides/admin-guides/manage_clusters/ppc64le/discovery/mtms_discovery.rst

@@ -51,13 +51,11 @@ The server definition will be like this::
 
 After the physical server is defined into xCATdb, the next thing is update the node definition with the example node attributes::
 
-  # chdef cn1 ip=10.0.101.1
-  1 object definitions have been created or modified.
+  chdef cn1 ip=10.0.101.1
 
-In order to do BMC configuration during the discovery progress, the following command is needed, for more info about chain, pls refer the **Chain** document in **Advanced Topics** chapter::
+In order to do BMC configuration during the discovery process, set ``runcmd=bmcsetup``. For more info about chain, please refer to :doc:`Chain <../../../../../advanced/chain/index>`   ::
 
-  # chdef cn1 chain="runcmd=bmcsetup"
-  1 object definitions have been created or modified.
+  chdef cn1 chain="runcmd=bmcsetup"
 
 Then, add node info into /etc/hosts and DNS::
 

docs/source/guides/admin-guides/manage_clusters/ppc64le/discovery/seq_discovery.rst

@@ -18,7 +18,7 @@ Predefine a group of nodes with desired IP address for host and IP address for F
     nodeadd cn1 groups=powerLE,all
     chdef cn1 mgt=ipmi cons=ipmi ip=10.0.101.1 bmc=50.0.101.1 netboot=petitboot installnic=mac primarynic=mac
 
-In order to do BMC configuration during the discovery progress, the following command is needed, for more info about chain, pls refer the **Chain** document in **Advanced Topics** chapter::
+In order to do BMC configuration during the discovery process, set ``runcmd=bmcsetup``. For more info about chain, please refer to :doc:`Chain <../../../../../advanced/chain/index>`   ::
 
     chdef cn1 chain="runcmd=bmcsetup"
 

docs/source/guides/admin-guides/manage_clusters/ppc64le/discovery/switch_discovery.rst

@@ -52,7 +52,7 @@ After switches are defined, the server node can be predefined with the following
     chdef cn1 mgt=ipmi cons=ipmi ip=10.0.101.1 bmc=50.0.101.1 netboot=petitboot installnic=mac primarynic=mac
     chdef cn1 switch=switch1 switchport=0
 
-In order to do BMC configuration during the discovery progress, the following command is needed, for more info about chain, pls refer the **Chain** document in **Advanced Topics** chapter::
+In order to do BMC configuration during the discovery process, set ``runcmd=bmcsetup``. For more info about chain, please refer to :doc:`Chain <../../../../../advanced/chain/index>`   ::
 
     chdef cn1 chain="runcmd=bmcsetup"