"J. Buck Caldwell" <buck_c@polygon.com> writes:

> Does NetBSD/vax support dual-porting SDI disks? ie, can you hook the
> A port to one machine, and the B port to another?

Only to the "normal" extent of being able to do exactly what you say.

There is no support for synchronizing the buffer caches of two
machines working in the same file system.  If you want to hook up an
SDI disk to two machines, you can, but (as with other operating
systems) you'll have to keep them from stepping on each other.  The
three most useful scenarios are a) using the disk from each of the two
machines at different times, b) using different partitions on each of
the two machines at the same time, and c) running a failover-scheme to
make whichever machine is currently the "passive" node mount the file
systems and take over the running of some service if the other one
goes down.  I'm not suggesting that VAXen ever do, of course!  :-)

Oh, yes, I've also heard of raw disk being used as a communications
area for shared data structures between processes on two machines.

-tih
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