> Also, in a previous question (http://groups.google.com/group/
> comp.os.plan9/browse_thread/thread/771294cf1d34c337) it was stated
> that streams are no longer used. So what's the present mechanism that
> replaces streams?
there isn't one. you can't dynamically reconfigure i/o paths in plan 9.
however, since everything's a file server, one can construct fairly
arbitrary chains of devices. (and given the bread/bwrite calls in the
kernel, it can be zero-copy.)
zB: aoe(3) presents basic block devices. partitions aren't supported.
however, sdaoe(3) which is a lightly specialized version of sdloop(3)
turns one into a sd(3) device, which does support partitions. sdloop
(only in 9atom) can do the same thing for anything that looks like a
regular file.
so imagine that i for some bizarre reason i wanted to run raid50
locally on aoe targets. i could run a fictive sdraid5 on a fictive
set of sdraid1 devices which in turn were built from sdaoe on top
of aoe. so you'd have
sdraid5* <-> sdraid1* <-> sdaoe <-> aoe <-> ether
maybe that looks like streams to you, even if it's not dynamically
reconfigurable.
personally, that looks more like Device in ken's file server
to me.
- erik
