How to configure fence device in redhat cluster suite

[senthil_kumar_1]

Hi All,

I would like to configure redhat cluster suite...

I came to know that we need to configure fence device while configuring cluster...

Could you please explain what is fence device and how to configure that for HP proliant blade server..We are using common chassis iLO to connect the blade...

[Matti_Kurkela]

Which version of RHEL are you using? (4, 5 or 6?)

Which is your preferred cluster configuration tool? Conga (= luci + ricci), or editing the cluster configuration XML file manually? Or something else?

An explanation on fence devices:

In a cluster, it is very important that each cluster member knows the state of the other members of the cluster. If a cluster member is certainly down (non-functional), the cluster can take steps to recover; but if one cluster member is in an unknown state, recovery is not possible until the unknown node is somehow brought to a known state. A fence device can force a cluster member to a known state: either by turning off its power, or by severing its connection to the cluster's shared resources (typically storage LUNs). Yes, they're both rather drastic actions, but if the cluster member is no longer responding to the normal cluster status query messages, that's the best you can do.

The easiest way to configure the fence devices is probably using Conga. Since you're using Proliant blades, your fence device type will be fence_ilo, and you should create one fence device for each blade.  You need to make sure that you can connect from the OS of each blade to the iLO IP addresses of each cluster member blade. You may want to create a user account specifically for the fencing agent on the iLOs of the cluster member blades: this user accound needs the ability to switch the power of the blade off and on, but it does not need console access.

For configuration details, please read the Cluster Administration guide that is appropriate for your RHEL version. The guides are available at the RedHat documentation site.

[senthil_kumar_1]

Hi Matti,

I am going to configure cluster on RHEL 5.

Now I am clear with fenceing...

And this is about conga...

Recently I have installed clustering packages in my server...

The packages luci and ricci have been installed...But I am not able to open Conga...

# rpm -qa | grep -i luci
luci-0.12.2-12.el5

# rpm -qa | grep -i ricci
ricci-0.12.2-12.el5


But I am not able to see the command "Conga / conga"...

# which Conga
/usr/bin/which: no Conga in (/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin)


# which conga
/usr/bin/which: no conga in (/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin)

How to get the command Conga / conga, Do I need to install any other package to get Conga / conga apart from luci and ricci?

How to launch Conga?

[Matti_Kurkela]

You really should read the Cluster Administration guide provided by RedHat.

See step 6 on the linked page.