HP Metro Cluster query!!

[Amit Manna_6]

Hi
Can any body throw some light on metro cluster

What is the role of arbitrator node in this?

And what are the precuations to be taken to shutdown the arbitrator nodes.

And how to add the nodes in the metro cluster when the server comes up.

Thanks in advance.

[Cem Tugrul]

Amit,

From the book from Peter S.Weygant "Clusters
for High Availability" second edition...
pp:187
"
metroclusters operates within a metropolitan
area;nodes maybe seperated by geographic distances no gretaer than 43 km.A metro cluster operates much like an ordinary SG cluster,with some additions;

- Special disk array HW&SW for data replication are used.

- Special control scripts are employed for pkgs.

- Arbitrator systems are used as tie-breakers
instead of local disks

Metroclusters are very similar to Campus clusters with the exception that MClusters often require rights-of-way from local goverments or utilities to lay network and data replication cable.MetroClusters also
require a different kind of tie-breaker system for ensuring that split-brain arise.Typically,Mclusters use an arbitrator
site containing additional nodes instead of cluster lock disks.

Mcluster architecture is implemented through
2 HP Products;

- Continous Access XP
- EMC SRDF
"

Good Luck,

[Alessandro Pilati]

Amit,
check this document for some details:
http://docs.hp.com/en/B7660-90010/index.html

have a look also to this past forum:
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=31411

Regards,
Alex

[melvyn burnard]

simply put, an arbitration node is another node in the cluster that is at a separate location from the two main data centres, and is used for arbitration, or cluster lock mechanism, in the event of a complete loss of one data centre.
Refer to the Designing Disaster Tolerant Clusters manual at:
http://docs.hp.com/en/ha#Metrocluster