R: [Linux-cluster] Ethernet Channel Bonding Configuration in RHELCluster Suite Setup

[Leandro Dardini]

> -----Messaggio originale-----
> Da: linux-cluster-bounces at redhat.com 
> [mailto:linux-cluster-bounces at redhat.com] Per conto di Balaji
> Inviato: venerdì 29 febbraio 2008 13.28
> A: ClusterGrp
> Oggetto: [Linux-cluster] Ethernet Channel Bonding 
> Configuration in RHELCluster Suite Setup
> 
> Dear All,
> 
>     I am new in RHEL Cluster Suite.
> 
>     I have Configure Cluster and Rebooted the system and then 
> cluster become active in primary node and other node as 
> passive and member status becomes Online for both the cluster nodes
>  
>     In Cluster Suite i am monitoring the resources as scripts 
> files and ipaddress and During network failure one of the 
> node or both the nodes are removed from the cluster member 
> and All the resources are stopped and then rebooted the 
> system only both the system are joining into the cluster member.
> 
>     I have followed the RHEL Cluster Suite Configuration 
> document "rh-cs-en-4.pdf" and I have found out Ethernet 
> Channel Bonding in Each Cluster Nodes will avoid the network 
> single point failure in cluster system.
>  
>     I have configured the Ethernet Channel Bonding with mode 
> as active-backup without fence device.
> 
>     Ethernet Channel Bonding Configuration Details are
>     1. In " /etc/modprobe.conf" file added the following 
> bonding driver support  
>        alias bond0 bonding
>        options bonding miimon=100 mode=1
>     2. Edited the "/etc/sysconfig/network-scripts/ifcfg-eth0" 
> file added the following configuration
>        DEVICE=eth0
>        USERCTL=no
>        ONBOOT=yes
>        MASTER=bond0
>        SLAVE=yes
>        BOOTPROTO=none
>     3. Edited the "/etc/sysconfig/network-scripts/ifcfg-eth1" 
> file added the following configuration
>        DEVICE=eth1
>        USERCTL=no
>        ONBOOT=yes
>        MASTER=bond0
>        SLAVE=yes
>        BOOTPROTO=none
>     4. Created a  network  script for the bonding device 
> "/etc/sysconfig/network-scripts/ifcfg-bond0"
>         DEVICE=bond0
>         USERCTL=no
>         ONBOOT=yes
>         IPADDR=192.168.13.109
>         NETMASK=255.255.255.0
>         GATEWAY=192.168.13.1
>     5. Reboot the system for the changes to take effect.
>     6. Configure Ethernet Channel Bonding
>     7. Rebooted the system and then cluster services are 
> active on both the nodes and member status of current node is 
> Online and other node as Offline
> 
>     I need clarification about Ethernet Channel Bonding will 
> work with Fence Device or not.
> 
>     I am not sure why this is happening. Can some one throw 
> light on this.
> 
> Regards
> -S.Balaji
> 

When there is a network failure, each member cannot reach the other one. Each member trigger the fence script to turn off the other one. Unfortunately the network is off, so the low level network interface take the fence script connection request in mind and wait for the network to come up. When the network is again available, each member can reach the fencing device and turn off the other. There is no simple way to avoid this. You can make network near 100% fault proof using bond device or you can use a STONITH fencing device, so the first member who regain network prevents the other to fence, or you can use three members. In a network failure no one have the quorum to fence the others.

Leandro