HP OpenVMS Systems

ask the wizard
Content starts here

Cluster Configurations?

» close window

The Question is:

In "Guidelines for OpenVMS Cluster Configurations" appendix D2 you state "For
 maximum performance and availability, use two disjoint FDDI LANs, each with
 dedicated host adapters and full-duplex FDDI intersite links  connected to
 GIGAswitch/FDDI bridges at
 each site. "
For the last years I have successfully used such configurations to provide high
 availability and high performance 3 and 4 site clusters.
One of the components used by our applications is the host based shadowing in
 order to provide full disaster redundancy
Now I am being told by Enterrasys that they will stop provide the GigaSwitches
 at the end of this year.
My questions:
1) Is there a prefered path from Compaq concerning the technology used for
 designing multpile site OpenVMS Clusters ?
2) What technology and implementations are Compaq using when you qualifying
 multiple site OpenVMS Clusters ?
3) Do you have any guidlines for calculating site recovery for  multiple site
 OpenVMS Clusters ?
Thanks in advance.

The Answer is :

  Host-based shadowing and the various other mechanisms and packages that
  are used within an OpenVMS Cluster are not particularly specific to the
  underlying physical media involved.
  The particular network media used and the associated mechanisms are of
  rather less interest than are the basic clustering latency and bandwidth
  requirements, and meeting the disparate physical media routing and the
  required level of redundancy of the physical media.  Once the basic
  latency and bandwidth requirements are met (eg: 10 megabit Ethernet; the
  site-specific requirements will likely require greater bandwidth), you
  will be looking at avoiding a single-point failure (such as having the
  redundant inter-site network links routed via non-adjacent conduit, and
  having multiple redundant network switches or network bridges.)
  ATM, Gigabit Ethernet and Fibre Channel are the most common approaches
  for remote access in current clustering configurations.
  In addition to the clustering information included in the two manuals
  in the OpenVMS manual set, disaster-tolerant clustering information is
  also available as part of the Disaster Tolerant Cluster Services (DTCS)
  services offering.

answer written or last revised on ( 6-NOV-2000 )

» close window