QBUS SCSI card...

From: Doc Shipley <doc_at_mdrconsult.com>
Date: Mon Feb 24 20:15:00 2003

On Mon, 24 Feb 2003, Zane H. Healy wrote:

> Doc wrote:
> > On Mon, 24 Feb 2003, Zane H. Healy wrote:
> >
> > > By a remote disk, I assume you're talking about a 3.5" SCSI disk sitting in
> > > a remote VMS or *BSD box? In such a configuration you still should (if
> > > possible) have a local swap disk.
> >
> > I know that's the standard wisdom, but the read/write speeds of all
> > the MFM disks I've tried on my RQDX3s are significantly slower than
> > network reads and writes.
>
> That's interesting. I'd really not taken the slowness of the MFM disks into
> account. It also makes a certain sense. Besides come to think of it, that
> "standard wisdom" is generally applied to VAXstation 3100 or 4000 class
> systems. Though I've been known to recommend booting a VAX 6000 class
> system off of a VAXstation 4000/vlc.

  Now that I agree with - my 3100s do a *lot* better with local swap,
and a little better with a local system disk.

> You're making me wish I could give this a try under VMS. I wonder where on
> earth I've got my pair of RD54's stashed. I know where everything else is
> that would be required to temporarily switch a PDP-11 over to a MicroVAX II.
> It would make for some interesting testing, and I've been wanting to us a
> MicroVAX II to practice my system tuning skills (improvements are more
> noticable on a MVII).

  I'd be quite interested to know what you find. I'm not willing to
discount inefficient drivers on the NetBSD side, but just the published
transfer rates for the MFM disks, let alone seek times, suggest that on
a decently configured network, local storage will be slower than NFS.

        Doc
Received on Mon Feb 24 2003 - 20:15:00 GMT