| > - does it make sense upgrading only one node in a VAXcluster to FDDI
> e.g. 4x VAX8800 continuing with Ethernet + VAX6000 connected to
> a new FDDI network
It might well, if, for example, the 6000 does a lot of satellite disk serving
or Pathworks service to PCs and needs more capacity than a single Ethernet
adapter can handle.
A number of customers who have a total network load exceeding that of a single
Ethernet have started using FDDI as a network backbone (even before the DEMFA
adapters were available). Being able to connect a 6000 directly to the
backbone for greater performance is just an added benefit.
Using multiple Ethernet adapters is another route you can take, esepcially for
systems like the 8000s for which no FDDI adapter is available.
> - is a VAX6000 with mixed network interfaces supportet from teh
> VAXcluster software,and if it possible, how works the load balancing
> between the FDDI and Ethernet interface.
Yes, using both an Ethernet and an FDDI interface at once is supported.
The path with the lowest latency is used. This is determined separately for
each separate remote node and happens in 3-second intervals. Note that for
this to balance the load, there must be multiple remote nodes so that different
paths are likely to be the fastest for each one.
Note that with both Ethernet and FDDI adapters in the same system, the FDDI,
although faster, isn't necessarily always chosen: if a given node is on the
same Ethernet segment to which the 6000's Ethernet adapter is connected, the
Ethernet may be a faster way to get to that node than sending a packet out the
FDDI interface and through a DECbridge 500 to get onto the Ethernet.
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