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Determining Cluster Bandwidth Requirements?

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The Question is:

Volume shadowing in a multiple site cluster.
Are there any guidelines to find out how big the network connection needs to be.
We upgrading an existing VAX cluster to Alpha and are going to add some DR
 functions to it at the same time. I'm trying to find the best solution to keep
 the data syncronized between the sites and the cost for the options. I have
 looked for some kind of s
ize info or guidelines for the size of the network pipe between sites but can't
 find anything beyond "at least 10MBit".

The Answer is :

  You need to determine how much bandwidth you need and particularly how
  quickly you need to resynchronize the data assuming host-based volume
  shadowing and particularly volume merges or volume copies
  The traditional minimum for clustering bandwidth and for latency is that
  of an IEEE 802.3 or Ethernet network; 10 megabits per second.  This is
  the lower network performance bound for a supported cluster configuration.
  For remote (or disaster-tolerant; DT) connections, this implies T3 or E3
  connection speeds, or faster.
  How fast a connection is required for your configuration depends on
  how many volumes are involved and how fast you need to (re)synchronize
  the contents of the shadowset volumes.  This is in addition to the
  steady-state network I/O performance requirements, of course.
  DT configuration design might initially looks comparatively trivial, but
  is in actuality surprisingly difficult to complete correctly and
  reliably -- the dependencies and the subtleties are many and varied.
  HP services has extensive experience in these and offers DT Services,
  and the OpenVMS Wizard strongly encourages any customer seeking to
  create a first-time DT configuration avail themselves of these HP
  Services DT Services offerings.

answer written or last revised on ( 8-DEC-2002 )

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