[Pacemaker] virtual IP or real IP address

[gilberto migliavacca]

Hi Tim

thanks for for your help. Now there's less fog in my brain

I'm trying

gilberto

Tim Serong wrote:
>  >>> On 10/28/2009 at 07:26 PM, gilberto migliavacca <gbmiglia at yahoo.it> wrote: 
>> Hi 
>>  
>> I have a question. I've seen in the mailing list 
>> a lot of example with the IPAddr/IPAddr2 resource agent 
>>  
>> this resource agent manages the Virtual IP. 
>>  
>> Could anybody explain me why I have to create a 
>> virtual IP istead of using the real IP? 
> 
> In brief, the idea is:
> 
> - You have (say) two nodes in an HA cluster, each with its
>   own unique IP address (i.e. the address you ssh to in order
>   to administer that node).
> - The "virtual" IP address is a third, different IP, which is
>   managed by the IPAddr2 RA.  This is active on only one node
>   at a time, and is managed by Pacemaker.
> - You set up colocation/ordering constraints so that the
>   IPAddr2 resource runs on the same node as an instance of
>   Apache (or whatever service you're providing).
> - Clients connect to that "virtual" IP, which can then failover to
>   the other node, if the node it's running on dies.
> 
> HTH,
> 
> Tim
> 
>