And plus. Please do not forget about contents of backuped data, it may be
not compressable at all ;) So, this DASD requires maximum tape count. And a
big number of clear DASDs (just formatted) may fit into one tape at the same
time.
The software compression case permits to calculate estimated
To: IBMVM@LISTSERV.UARK.EDU
Subject: Re: DDR Question
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 VS=
E program, that would tell you how
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:
:36 PM
Please respond to
The IBM z/VM Operating System IBMVM@LISTSERV.UARK.EDU
To
IBMVM@LISTSERV.UARK.EDU
cc
Subject
Re: DDR Question
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
System IBMVM@LISTSERV.UARK.EDU
03/30/2011 10:36 PM
Please respond to
The IBM z/VM Operating System IBMVM@LISTSERV.UARK.EDU
To
IBMVM@LISTSERV.UARK.EDU
cc
Subject
Re: DDR Question
Slight brain fart, I didn't even think of hardware compression duh! I
guess the only real way to to do
Maybe you were thinking of the IBM DITTO product?
It's available for VSE, VM/CMS and z/OS.
Its tape map function reads a tape and tells you how many actual feet wer
e
written.
From the DITTO manual:
TMP (Tape Map)
Purpose Summarize tape contents. For a specified number of files on the
Hello all,
I seem to remember from long ago a program, or option of DDR ( I sure can't
find it now) that would do DDR DUMP and not actually produce an output tape
but just print a byte count of what would have been dumped...
Does anyone know what I am talking about?
Tom
Sent: Wednesday, March 30, 2011 11:16 AM
To: IBMVM@LISTSERV.UARK.EDU
Subject: DDR Question
Hello all,
I seem to remember from long ago a program, or option of DDR ( I sure can't
find it now) that would do DDR DUMP and not actually produce an output tape but
just print a byte count of what would
*Subject:* DDR Question
Hello all,
I seem to remember from long ago a program, or option of DDR ( I sure
can't find it now) that would do DDR DUMP and not actually produce an output
tape but just print a byte count of what would have been dumped...
Does anyone know what I am talking about
, 2011 11:37 AM
To: IBMVM@LISTSERV.UARK.EDU
Subject: Re: DDR Question
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.
On Wed, Mar 30, 2011 at 11:30 AM, Schuh, Richard
rsc...@visa.commailto:rsc...@visa.com
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
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 donot obvious to me.
However, once you do have a compressed tape, DITTO TMP will tell you how much
tape the compressed dataset took
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
: Wednesday, March 30, 2011 8:37 PM
To: IBMVM@LISTSERV.UARK.EDU
Subject: Re: DDR Question
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
*Sent:* Wednesday, March 30, 2011 8:37 PM
*To:* IBMVM@LISTSERV.UARK.EDU
*Subject:* Re: DDR Question
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
[mailto:IBMVM@LISTSERV.UARK.EDU] On Behalf
Of Tom Huegel
Sent: Wednesday, March 30, 2011 9:32 PM
To: IBMVM@LISTSERV.UARK.EDU
Subject: Re: DDR Question
I don't believe I ever worked with 200 bpi tapes, but I did work were we had 8
tape drives 6 were 800 bpi and 2 were 1600 bpi with the optional high
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