How to transfer data FAST? - test-drb@ccmp.vtda.org

27 Jun 2005

On Thu, 23 Jun 2005 Paul Koning <pkoning at equallogic.com> wrote:

...

>>>> "Zane" == Zane H Healy <healyzh at aracnet.com> writes:

  Zane> At 9:19 AM -0400 6/23/05, Paul Koning wrote:
  >> >>>> "Zane" ==
Zane H Healy <healyzh at aracnet.com> writes:   >>
  Zane> As I understand it, the issue was with variable byte blocks.  I
  Zane> had zero issues installing RSTS/E, and I think a couple layered
  Zane> products off of 4mm DAT.  However, DECnet/E would not install
  Zane> off of DAT.
 > You mean variable length blocks?  If it
doesn't support that, it
> isn't a proper tape.  Proper tapes handle any block size, odd or
> even, from 14 up to at least 8k or so. 
  Zane> Yes, that's what I mean.  It is my understanding from when I
  Zane> got some help figuring this out (I think by this list), that
  Zane> was the problem. It wouldn't install from DAT, but had zero
  Zane> issues with TK50.

 Ok.  RSTS does assume/require that tapes are designed by competent
 designers.  I'm surprised you didn't run into similar issues with
 other operating systems. 
He should have. RSX expects tape drive to be able to deliver variable size
blocks as well. The distribution tapes hold 512 byte, 80 byte and 4144
byte size records. (As well as 0 byte file mark records.)

	Johnny

Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt at update.uu.se           ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol