[Linux-cluster] redhat HA cluster we need shared storage

[Digimer]

On 10-09-27 09:12 AM, Rohit tripathi wrote:
> Dear sir
>  
> I need to know for redhat HA cluster we need shared storage it is
> compulsory or not or we can configure HA cluster without shared storage.
>  
>  
> regards
>  
> Rohit

Short answer;

Yes, a cluster is required.

Longer answer;

Just to clarify, there are two types of cluster; HA (Heartbeat) and RHCS
(Red Hat Cluster Services). Assuming by "shared storage" you are talking
about GFS2 partitions, then yes, you must have a cluster.

The reason is that GFS2 (and possibly OCFS2, though I am not certain)
require the DLM (Distributed Lock Manager) provided by the cluster to
ensure safe access to the shared storage. Further, the cluster provides
critical fencing so that nodes that fail can be removed from the cluster
and safe access to the shared storage can be regained.

Cheers,

-- 
Digimer
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