Building an Extended Distance Cluster Using Serviceguard and Software RAID
Rules for Separate Network and Data Links
Rules for Separate Network and Data Links
•There must be less than 200 milliseconds of latency in the network between the data centers.
•No routing is allowed for the networks between the data centers.
•Routing is allowed to the third data center if a Quorum Server is used in that data center.
•The maximum distance between the data centers for this type of configuration is currently limited by the maximum distance supported for the networking type or Fibre Channel link type being used, whichever is shorter.
•There can be a maximum of 500 meters between the Fibre Channel switches in the two data centers if
•There must be at least two alternately routed networking links between each primary data center to prevent the “backhoe problem”. The “backhoe problem” can occur when all cables are routed through a single trench and a tractor on a construction job severs all cables and disables all communications between the data centers. It is allowable to have only a single network link routed from each primary data center to the third location, however in order to survive the loss of the network link between a primary data center and the arbitrator data center, the network routing should be configured so that a primary data center can also reach the arbitrator via a route which passes through the other primary data center.
•There must be at least two alternately routed Fibre Channel Data Replication links between each data center.
•See the HP Configuration Guide (available through your HP representative) for a list of supported Fibre Channel hardware.
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