[Linux-cluster] IP Resource behavior with Red Hat Cluster

[Parvez Shaikh]

Thanks a ton Jakov. It has clarified my doubts.

Yours gratefully,
Parvez

On Sat, Dec 25, 2010 at 6:34 AM, Jakov Sosic <jakov.sosic at srce.hr> wrote:
> On 12/24/2010 05:46 PM, Parvez Shaikh wrote:
>> Hi Jakov
>>
>> Thank you for your response. My two hosts have multiple network
>> interfaces or ethernet cards. I understood from your email, that the
>> IP corresponding to "cluster node name" for both hosts, should be in
>> the same subnet before a cluster could bring virtual IP up.
>
> No... you misunderstood me. I meant that if the virtual address is
> 192.168.25.X, than you have to have interface on each node that is set
> up with the ip address from the same subnet. That interface does not
> need to correspond to the cluster node name. For example:
>
> node1 - eth0 - 192.168.1.11 (netmask 255.255.255.0)
> node2 - eth0 - 192.168.1.12 (netmask 255.255.255.0)
>
> IP resource - 192.168.25.100
>
>
> Now, how do you expect the cluster to know what to do with IP resource?
> On which interface can cluster glue 192.168.25.100? eth0? But why eth0?
> And what is the netmask? What about routes?
>
> So, you need to have for example eth1 on both machines set up in the
> same subnet, so that cluster can glue IP address from IP resource to
> that exact interface (which is set up statically). So you also have to
> have for example:
>
> node1 - eth1 - 192.168.25.47 (netmask 255.255.255.0)
> node2 - eth1 - 192.168.25.48 (netmask 255.255.255.0)
>
> Now, rgmanager will know where to activate IP resource, because
> 192.168.25.100 belongs to 192.168.25.0/24 subnet, which is active on
> node1/eth1 and node2/eth2.
>
> If you were to have another IP resource, for example 192.168.240.44, you
> would need another interface with another set of static ip addresses on
> every host you intend to run IP resource on...
>
>
> I hope you get it correctly now.
>
>
>
>
>
> --
> Jakov Sosic
> www.srce.hr
>
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