data sets..
Best Regards,
Yifat
-Original Message-
From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf
Of Andrew N Wilt
Sent: Friday, December 03, 2010 1:45 AM
To: IBM-MAIN@bama.ua.edu
Subject: Re: Hardware-assisted compression: not CPU-efficient?
Ron
, 2010 12:22 PM
To: IBM-MAIN@bama.ua.edu
Subject: Re: Hardware-assisted compression: not CPU-efficient?
Pardon my bringing back an old thread, but -
I wanted to see how much better is the COMPRESS option over the HWCOMPRESS
in regards to CPU time and was pretty surprised when my results suggested
Hi,
DSS DUMP supports COMPRESS/HWCOMPRESS keyword and I found out in my test
that HWCOMPRESS costs more CPU than COMPRESS.
Is it normal?
Currently we're dumping huge production data to tape and in order to
alleviate the tape channel utilization we need to compress the data before
writing to
in the first place.
Ron
-Original Message-
From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf Of
Johnny Luo
Sent: Thursday, December 02, 2010 2:13 AM
To: IBM-MAIN@bama.ua.edu
Subject: [IBM-MAIN] Hardware-assisted compression: not CPU-efficient?
Hi,
DSS DUMP
Ron, is it generally the case that CPU is saved on read? I'm seeing QSAM
with HDC jobsteps showing very high CPU. But then they seem to both write
and read. Enough CPU to potentially suffer from queuing.
(And, yes, I know you were talking about a different category of HDC
usage.)
Martin
Hi
A few years ago I have tried with hardware compression, as we are using
intensively the zlib library (http://www.ietf.org/rfc/rfc1950.txt) to
compress/expand .
Never got a proper answer, and till now not clear, in which case would
bring the hardware compression some CPU reduction
Miklos,
What do you mean by 'zlib'? Is it free on z/OS?
Best Regards,
Johnny Luo
On Thu, Dec 2, 2010 at 8:10 PM, Miklos Szigetvari
miklos.szigetv...@isis-papyrus.com wrote:
Hi
A few years ago I have tried with hardware compression, as we are using
intensively the zlib library
Hi
Yes, it is a c library
On 12/2/2010 1:26 PM, Johnny Luo wrote:
Miklos,
What do you mean by 'zlib'? Is it free on z/OS?
Best Regards,
Johnny Luo
On Thu, Dec 2, 2010 at 8:10 PM, Miklos Szigetvari
miklos.szigetv...@isis-papyrus.com wrote:
Hi
A few years ago I have tried with
On Thu, 2 Dec 2010 02:53:17 -0800, Ron Hawkins wrote:
The saving in hardware assisted compression is in decompression - when you
read it. Look at what should be a much lower CPU cost to decompress the files
during restore and decide if the speed of restoring the data concurrently is
worth the
List [mailto:ibm-m...@bama.ua.edu] On Behalf
Of Johnny Luo
Sent: יום ה 02 דצמבר 2010 12:13
To: IBM-MAIN@bama.ua.edu
Subject: Hardware-assisted compression: not CPU-efficient?
Hi,
DSS DUMP supports COMPRESS/HWCOMPRESS keyword and I found out in my test
that HWCOMPRESS costs more CPU than COMPRESS
Yifat Oren yi...@tmachine.com wrote in message
news:3d0c19e6913742b282eeb9a7c4ae3...@yifato...
Hi Johnny,
I was under the impression that for DFDSS DUMP, COMPRESS and
HWCOMPRESS are
synonymous;
Are you saying they are not?
If you are writing to tape why not use the drive
On Thu, 2 Dec 2010 16:29:56 +0200, Yifat Oren wrote:
I was under the impression that for DFDSS DUMP, COMPRESS and HWCOMPRESS are
synonymous;
Are you saying they are not?
Yes, they are not synonymous. HWCOMPRESS uses the CMPSC instruction
(dictionary-based compression). COMPRESS uses RLE
On 2 December 2010 05:53, Ron Hawkins ron.hawkins1...@sbcglobal.net wrote:
Johnny,
The saving in hardware assisted compression is in decompression - when you
read it. Look at what should be a much lower CPU cost to decompress the files
during restore and decide if the speed of restoring the
On Thu, 2 Dec 2010 12:09:23 -0500, Tony Harminc wrote:
On 2 December 2010 05:53, Ron Hawkins wrote:
The saving in hardware assisted compression is in
decompression - when you read it. Look at what should be a
much lower CPU cost to decompress the files during restore
and decide if the speed
Unfortunately, IBM, et. al. *DO NOT* bill on elapsed time.
More CPU used for Dump is less CPU available for productive work, or
worse yet, a bigger software bill!
snip
Increased CPU time to do the dump does not necessarily mean that
the elapsed time is longer. In fact, by compressing the
: [IBM-MAIN] Hardware-assisted compression: not CPU-efficient?
Ron, is it generally the case that CPU is saved on read? I'm seeing QSAM
with HDC jobsteps showing very high CPU. But then they seem to both write
and read. Enough CPU to potentially suffer from queuing.
(And, yes, I know you were
: [IBM-MAIN] Hardware-assisted compression: not CPU-efficient?
On Thu, 2 Dec 2010 02:53:17 -0800, Ron Hawkins wrote:
The saving in hardware assisted compression is in decompression - when
you
read it. Look at what should be a much lower CPU cost to decompress the
files
during restore
To: IBM-MAIN@bama.ua.edu
Subject: Re: [IBM-MAIN] Hardware-assisted compression: not CPU-efficient?
On Thu, 2 Dec 2010 02:53:17 -0800, Ron Hawkins wrote:
The saving in hardware assisted compression is in decompression - when
you
read it. Look at what should be a much lower CPU cost
Original Message-
From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf
Of Hal Merritt
Sent: Friday, 3 December 2010 6:44 AM
To: IBM-MAIN@bama.ua.edu
Subject: Re: Hardware-assisted compression: not CPU-efficient?
Conversely, sometimes it is hard to get the backups
opposed to back-up duration which is usually outside of
any business critical path.
It shouldn't be, especially if back-ups have to complete before sub-systems can
come up.
If we ran out of window, we had senior IT management and business contacts
decide which was more critical: back-up;
cost of the backup.
Ron
-Original Message-
From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On
Behalf Of
Tony Harminc
Sent: Thursday, December 02, 2010 9:09 AM
To: IBM-MAIN@bama.ua.edu
Subject: Re: [IBM-MAIN] Hardware-assisted compression: not CPU-efficient?
On 2
List [mailto:ibm-m...@bama.ua.edu] On
Behalf Of
Ted MacNEIL
Sent: Thursday, December 02, 2010 1:14 PM
To: IBM-MAIN@bama.ua.edu
Subject: Re: [IBM-MAIN] Hardware-assisted compression: not CPU-efficient?
opposed to back-up duration which is usually outside of
any business critical path
...@sbcglobal.net
To:
IBM-MAIN@bama.ua.edu
Date:
12/02/2010 04:21 PM
Subject:
Re: Hardware-assisted compression: not CPU-efficient?
Tony,
You are surprised, and then you explain your surprise by agreeing with
me.
I'm confused.
I'm not sure if you realized that the Huffman encoding
On 2 December 2010 18:20, Ron Hawkins ron.hawkins1...@sbcglobal.net wrote:
Tony,
You are surprised, and then you explain your surprise by agreeing with me.
I'm confused.
Well now I'm confused; I'm not sure how I did what you say.
I'm not sure if you realized that the Huffman encoding
any tests with HWCOMPRESS.
Ron
-Original Message-
From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On
Behalf Of
Tony Harminc
Sent: Thursday, December 02, 2010 4:51 PM
To: IBM-MAIN@bama.ua.edu
Subject: Re: [IBM-MAIN] Hardware-assisted compression: not CPU-efficient
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