[rescue] Prestoserve NVRAM SIMMs

[Kurt Mosiejczuk]

On Sun, 17 Feb 2002, Brian Hechinger wrote:

> >    Since one of this machine's projected duties is being the NFS server for
> > diskless units, Prestoserve acceleration would be quite desirable. Is
> > Prestoserve still supported in Solaris 8? Where might I get the Prestoserve
> > software?

> yes, they should work with 8, HOWEVER, they are for the CLIENT machines, not
> the server machines.  they are a very early implementation of ram-only cachefs.
> they will do you no good in a server.  sorry!!

Um... I know I'm setting myself up, but...

BZZZZT!!  Wrong.

They are for the NFS SERVERS.  NFS writes are defined to be synchronous
(I seem to recall some places where v3/v4 bend this maybe, but that's
another story).  Synchronous writes are SLOW.  And sync writes are the
biggest slow down for NFS servers.  The NVSIMMs are used to batch up
these sync writes until they can be dumped to disk in a more optimal
way (otherwise there can be no re-ordering of writes and such).  They
are non-volitale so that if the server goes down, the change is still
"committed".

Has nothing to do with being ram-only or cachefs. (well, maybe since cachefs
is layered atop NFS).

--Kurt