C-mode quorum

[saranraj456]

Hi Folks,

I just jumped off to learn c-mode from 7-mode,here are the few doubts raised while starting.

1.What kind of information does this quorum actually contains.? , does the space for this is accumulated from vserver root volume?

2.Why only the set of nodes, involved to be a part in cluster  ( i read the system administration guide, didnt catch up how all the nodes involvement in cluster would affect the data)

3.What would happen if there is a problem in the set of nodes having cluster , does it affect the availability of data?

4.can some one explain me about the tie breaker situation , where the epsilon is used.

5.Where does this rdb resides in each node?

Above all , i read the system admin guide it doesnt have enough info to answer my questions>

Thanks

Saran

[singhharish]

1-The quorum is basically used for making the Cluster function properly.In the quorum the nodes which are participating in the cluster

vote to select a master node who will maintain the function of the cluster like synchronising the information in the cluster.

A quorum is manadtory to make the cluster normal operation.

The quorum is a cluster level (admin vserver) process.

2-This one is not clear to me.

3-Let say you have a four node cluster n1-n2(in pair),n3-n4(in-pair).and n1 is the master here.if the master goes down a new selection process will

occur for new master.and during the master is down there is thing you can perform on n1 i.e. you cant move in and put volumes from this n1 node.

and and the same time a storage failover to n2 occur if it is a for ex. hardware issue in n1 and all the data will be served by n2 as usual.

5-RDB is the vol0 volume which is created on every node of the cluster.you can find the location of the RDB logs under /mroot/etc/log/mlog.

I hope i make something clear to you.I write whatever i know.Please correct or modify any point if necessary.

Regards,