[kexec-tools] Add a kdump-in-cluster-environment.txt in RPM package

[WANG Chao]

commit 11bb4785f8f36f43cba1e5e23f11ae5b20818d70
Author: arthur <zzou at redhat.com>
Date:   Thu Jan 16 14:33:56 2014 +0800

    Add a kdump-in-cluster-environment.txt in RPM package
    
    Since kdump already support dump in cluster environment, this patch
    add a howto file to RPM package to describe how to configure kdump
    in cluster environment.
    
    Signed-off-by: arthur <zzou at redhat.com>
    Acked-by: Vivek Goyal <vgoyal at redhat.com>

 kdump-in-cluster-environment.txt |   66 ++++++++++++++++++++++++++++++++++++++
 1 files changed, 66 insertions(+), 0 deletions(-)
---
diff --git a/kdump-in-cluster-environment.txt b/kdump-in-cluster-environment.txt
new file mode 100644
index 0000000..c27a5d7
--- /dev/null
+++ b/kdump-in-cluster-environment.txt
@@ -0,0 +1,66 @@
+Kdump-in-cluster-environment HOWTO
+
+Introduction
+
+Kdump is a kexec based crash dumping mechansim for Linux. This docuement 
+illustrate how to configure kdump in cluster environment to allow the kdump 
+crash recovery service complete without being preempted by traditional power
+fencing methods. 
+
+Overview
+
+Kexec/Kdump
+
+Details about Kexec/Kdump are available in Kexec-Kdump-howto file and will not
+be described here.
+
+fence_kdump
+
+fence_kdump is an I/O fencing agent to be used with the kdump crash recovery 
+service. When the fence_kdump agent is invoked, it will listen for a message 
+from the failed node that acknowledges that the failed node is executing the 
+kdump crash kernel. Note that fence_kdump is not a replacement for traditional
+fencing methods. The fence_kdump agent can only detect that a node has entered
+the kdump crash recovery service. This allows the kdump crash recovery service
+complete without being preempted by traditional power fencing methods. 
+
+fence_kdump_send
+
+fence_kdump_send is a utility used to send messages that acknowledge that the 
+node itself has entered the kdump crash recovery service. The fence_kdump_send
+utility is typically run in the kdump kernel after a cluster node has 
+encountered a kernel panic. Once the cluster node has entered the kdump crash 
+recovery service, fence_kdump_send will periodically send messages to all 
+cluster nodes. When the fence_kdump agent receives a valid message from the 
+failed nodes, fencing is complete.
+
+How to configure cluster environment:
+
+If we want to use kdump in cluster environment, fence-agents-kdump should be 
+installed in every nodes in the cluster. You can achieve this via the following 
+command:
+
+  # yum install -y fence-agents-kdump
+
+Next is to add kdump_fence to the cluster. Assuming that the cluster consists 
+of three nodes, they are node1, node2 and node3, and use Pacemaker to perform
+resource management and pcs as cli configuration tool. 
+
+With pcs it is easy to add a stonith resource to the cluster. For example, add
+a stonith resource named mykdumpfence with fence type of fence_kdump via the 
+following commands:
+  
+   # pcs stonith create mykdumpfence fence_kdump \
+     pcmk_host_check=static-list pcmk_host_list="node1 node2 node3"
+   # pcs stonith update mykdumpfence pcmk_monitor_action=metadata --force
+   # pcs stonith update mykdumpfence pcmk_status_action=metadata --force
+   # pcs stonith update mykdumpfence pcmk_reboot_action=off --force
+   
+Then enable stonith
+   # pcs property set stonith-enabled=true
+
+How to configure kdump:
+
+Actually there is nothing special in configuration between normal kdump and
+cluster environment kdump. So please refer to Kexec-Kdump-howto file for more
+information.