Just don't compress the data more than once. If hdwe compression is
going to happen, don't let it be passed thru a s/w compression stage.
Double compression isn't twice as dense or good. It probably will
explode to more than you started with.
Jim
On 3/30/2011 11:36 PM, Tom Huegel wrote:
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Slight brain fart, I didn't even think of hardware compression duh! I guess
the only real way to to do it is just experimentation.
I still seem to remember a program from long ago, and it may have been a VSE
program, that would tell you how many bytes would go to the tape, in fact I
think it told you how many feet of tape (2400/3400) would be used..
Thanks guys.
On Wed, Mar 30, 2011 at 5:14 PM, Tom Duerbusch
<duerbus...@stlouiscity.com>wrote:
If you are doing software compression, then, perhaps use the Pipe DDR stage
and route it to the "count" stage.
But knowing how much compression the hardware will do....not obvious to me.
However, once you do have a compressed tape, DITTO TMP will tell you how
much tape the compressed dataset took on the media.
Tom Duerbusch
THD Consulting
Rich Greenberg<ric...@panix.com> 3/30/2011 4:55 PM>>>
On: Wed, Mar 30, 2011 at 11:37:00AM -0700,Tom Huegel Wrote:
} That doesn't show the compressed byte count is (would be). The goal here
is
} to be able to predict how many tapes I will need to do backups.
If you are doing hardware compression in the tape drive, I don't think
there is any way for DDR to know the compressed byte count. Software
compression, yes it would.
I suspect that the easiest way to determine the tape counts will be
experimentally.
--
Rich Greenberg Sarasota, FL, USA richgr atsign panix.com + 1 941 378
2097
Eastern time. N6LRT I speak for myself& my dogs only. VM'er since
CP-67
Canines: Val, Red, Shasta, Zero& Casey (At the bridge)
Owner:Chinook-L
Canines: Red& Cinnar (Siberians) Retired at the beach Asst
Owner:Sibernet-L
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<div>Slight brain fart, I didn't even think of hardware compression duh=
! I guess the only=A0real way to to do it is just experimentation.</div><di=
v>I still seem to remember a program from long ago, and it may have been a =
VSE program, that would tell you=A0how many bytes would go to the tape, in =
fact I think it told you how many feet of tape (2400/3400) would be used.. =
</div>
<div>=A0</div><div>Thanks guys.=A0<br><br></div><div class=3D"gmail_quote">=
On Wed, Mar 30, 2011 at 5:14 PM, Tom Duerbusch<span dir=3D"ltr"><<a hre=
f=3D"mailto:duerbus...@stlouiscity.com";>duerbus...@stlouiscity.com</a>><=
/span> wrote:<br>
<blockquote style=3D"margin: 0px 0px 0px 0.8ex; padding-left: 1ex; border-l=
eft-color: rgb(204, 204, 204); border-left-width: 1px; border-left-style: s=
olid;" class=3D"gmail_quote">If you are doing software compression, then, p=
erhaps use the Pipe DDR stage and route it to the"count" stage.<=
br>
But knowing how much compression the hardware will do....not obvious to me.=
<br>
<br>
However, once you do have a compressed tape, DITTO TMP will tell you how mu=
ch tape the compressed dataset took on the media.<br>
<br>
Tom Duerbusch<br>
THD Consulting<br>
<br>
>>> Rich Greenberg<<a href=3D"mailto:ric...@panix.com";>richgr@=
panix.com</a>> 3/30/2011 4:55 PM>>><br>
<div><div></div><div class=3D"h5">On: Wed, Mar 30, 2011 at 11:37:00AM -0700=
,Tom Huegel Wrote:<br>
<br>
} That doesn't show the compressed byte count is (would be). The goal h=
ere is<br>
} to be able to predict how many tapes I will need to do backups.<br>
<br>
If you are doing hardware compression in the tape drive, I don't think<=
br>
there is any way for DDR to know the compressed byte count. =A0Software<br>
compression, yes it would.<br>
<br>
I suspect that =A0the easiest way to determine the tape counts will be<br>
experimentally.<br>
<br>
--<br>
Rich Greenberg =A0Sarasota, FL, USA richgr atsign<a href=3D"http://panix.c=
om" target=3D"_blank">panix.com</a> =A0<a href=3D"tel:%2B%201%20941%20378%2=
02097">+ 1 941 378 2097</a><br>
Eastern time. =A0N6LRT =A0I speak for myself& my dogs only. =A0 =A0VM&=
#39;er since CP-67<br>
Canines: Val, Red, Shasta, Zero& Casey (At the bridge) =A0 =A0 =A0 =A0=
Owner:Chinook-L<br>
Canines: Red& Cinnar (Siberians) =A0Retired at the beach =A0Asst Owner=
:Sibernet-L<br>
</div></div></blockquote></div><br>
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--
James Bohnsack
(972) 596-6377 home/office
(972) 342-5823 cell
