[Linux-cluster] Can two clusters have same name?

[Chrissie Caulfield]

Chaitanya Kulkarni wrote:
> Thanks for your reply Chrissie.
> 
> But is this, i.e. deployment of clusters with same name, a valid
> scenario? How often (as in say 1 in a 100) may I see such deployments,
> if at all?
> 

Sorry, I really have no idea how many times you might see such
deployments. How would I work it out?! Cluster names are chosen by the
administrators ... those people are not easily predictable ;-)

Chrissie


> 
> On Mon, Mar 16, 2009 at 1:28 PM, Chrissie Caulfield <ccaulfie at redhat.com
> <mailto:ccaulfie at redhat.com>> wrote:
> 
>     Chaitanya Kulkarni wrote:
>     > Hi All,
>     >
>     > What happens if in the same network, we try to create two clusters
>     with
>     > the same name?
>     >
>     > Does it cause any problem?
> 
>     YES LOTS!
> 
>     At best the two clusters will merge into one, at worst you will get node
>     evictions because of clashes between node IDs
> 
>     Actually you *can* do this if you change the cluster_id/multicast
>     address or port number in cluster.conf. But need to be careful and it is
>     not recommended.
> 
>     The main reason I say not to do this is that GFS volumes have the
>     cluster name embedded in the super block. If you have two clusters with
>     the same cluster name on the same SAN then it's going to be very easy to
>     totally corrupt the GFS filesystem by mounting it on two different
>     clusters.
> 
> 
>     Chrissie
>