z/OS MVS Initialization and Tuning Guide:
Because SCM does not support persistence of data across IPLs, VIO data
can only be paged out to DASD. Therefore, even when SCM is installed you
must still maintain a minimum amount of storage that supports paging for
all of your VIO data, and a minimum am
d10j...@us.ibm.com (Jim Mulder) writes:
> it might be faster to read it from the DB2 data set, because DB2
> (via Media Manager) uses zHPF, but z/OS has not been enhanced to
> use zHPF for page data sets.
in 1980, I got con'ed into doing channel-extender for STL that was
moving 300 people from t
And if the buffer page is paged out to SCM, it should be faster to read
it from
SCM than from the DB2 data set. But if it is paged out to a page data
set,
it might be faster to read it from the DB2 data set, because DB2
(via Media Manager) uses zHPF, but z/OS has not been enhanced to
use zHP
On Tue, 18 Apr 2017 00:47:55 -0500, Barbara Nitz wrote:
>>I don't want to turn this into a debugging session, but this is what I see in
>>RMF3 on the non-DB2 utility system.
>>All of the TPX 'regions' are below this list sorted by Aux Slots. No task
>>shows any page-ins.
>
>Not sure that you h
> -Original Message-
> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On
> Behalf Of Greg Dyck
> Sent: 18 April, 2017 15:58
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: Re: Paging subsystems in the era of bigass memory
>
> On 4/18/2017 2:25
On 4/18/2017 2:25 AM, Vernooij, Kees - KLM , ITOPT1 wrote:
As I said, I remember reading this a long time ago, I don't know the details
anymore, whether the source was reliable and whether it is still working this
way. Only a DB2 internal expert should be able to tell.
...
On 12 April 2017 at
-
> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On
> Behalf Of Tony Harminc
> Sent: 12 April, 2017 18:45
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: Re: Paging subsystems in the era of bigass memory
>
> On 12 April 2017 at 10:16, Tom Marchant &l
>I don't want to turn this into a debugging session, but this is what I see in
>RMF3 on the non-DB2 utility system.
>All of the TPX 'regions' are below this list sorted by Aux Slots. No task
>shows any page-ins.
Not sure that you haven't already done this: Use IPCS active on that system,
and u
-Original Message-
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf
Of Graham Harris
Sent: Thursday, April 13, 2017 1:41 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: (External):Re: Paging subsystems in the era of bigass memory
Have you got RMF3?
Tried looking
On Wed, 12 Apr 2017 22:18:22 -0500, Mike Schwab wrote:
>Here is an IBM presentation on how to tune z/OS and DB2 memory,
>including some parameters to set.
>http://www.mdug.org/Presentations/Large%20Memory%20DB2%20Perf%20MDUG.pdf
Thanks for sharing!
Regards,
Art Gutowski
General Motors, LLC
W
> robin...@sce.com
>
>
> -Original Message-
> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On
> Behalf Of Mike Schwab
> Sent: Wednesday, April 12, 2017 8:18 PM
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: (External):Re: Paging subsystems in
fice ⇐=== NEW
robin...@sce.com
-Original Message-
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf
Of Mike Schwab
Sent: Wednesday, April 12, 2017 8:18 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: (External):Re: Paging subsystems in the era of bigass memory
Here is an IBM
Just check with our DB2 SYSPROG, same here.
Carmen
- Original Message -
From: "Mike Schwab"
To: IBM-MAIN@LISTSERV.UA.EDU
Sent: Wednesday, April 12, 2017 10:18:22 PM
Subject: Re: Paging subsystems in the era of bigass memory
Here is an IBM presentation on how to tun
Here is an IBM presentation on how to tune z/OS and DB2 memory,
including some parameters to set.
http://www.mdug.org/Presentations/Large%20Memory%20DB2%20Perf%20MDUG.pdf
On Wed, Apr 12, 2017 at 2:55 PM, Art Gutowski wrote:
> Did someone on this thread say DB2??
>
> We have been experiencing simi
RV.UA.EDU] On Behalf
Of Carmen Vitullo
Sent: Wednesday, April 12, 2017 1:02 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: EXTERNAL: Re: Paging subsystems in the era of bigass memory
Yes, and Thank you Art for that - I've passed this info on to our DB2 SYSPROG
Carmen
- Original Message ---
Yes, and Thank you Art for that - I've passed this info on to our DB2 SYSPROG
Carmen
- Original Message -
From: "Art Gutowski"
To: IBM-MAIN@LISTSERV.UA.EDU
Sent: Wednesday, April 12, 2017 2:55:53 PM
Subject: Re: Paging subsystems in the era of bigass memory
Did
Did someone on this thread say DB2??
We have been experiencing similar AUX storage creep on our DB2 systems,
particularly during LARGE reorgs (more of a gallop than a creep). Our DB2 guys
did some research, opened an ETR with IBM, and found this relic:
Q:
"[Why was] set realstorage_managemen
The topic seems to of morphed
from
Do I need to acheive a 30% page dataset utilization from virtual storage stable
LPAR with a single large DB2
to
Running many DB2s in a single LPAR I seem to have a memory leak that requires
periodic IPLs to avoid an aux storage problem
other than some common wo
shortages
what to do? add some more locals? NO!
Carmen
- Original Message -
From: "Jesse 1 Robinson"
To: IBM-MAIN@LISTSERV.UA.EDU
Sent: Wednesday, April 12, 2017 12:56:19 PM
Subject: Re: Paging subsystems in the era of bigass memory
I'd like to pull this disc
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf
Of Tom Marchant
Sent: Wednesday, April 12, 2017 10:15 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: (External):Re: Paging subsystems in the era of bigass memory
On Wed, 12 Apr 2017 12:44:32 -0400, Tony Harminc wrote:
>On 12
000a2a8c2020-dmarc-requ...@listserv.ua.edu (Tom Marchant) writes:
> Are you suggesting that before DB2 references a page containing a
> buffer, it checks to see if it is paged out? And that if it is paged out,
> it doesn't use the record in the buffer, but instead reads it into a
> different
On Wed, 12 Apr 2017 12:44:32 -0400, Tony Harminc wrote:
>On 12 April 2017 at 10:16, Tom Marchant <
>000a2a8c2020-dmarc-requ...@listserv.ua.edu> wrote:
>[DB2]
>
>> It still makes no sense to me. It certainly can't read the record into the
>> same page, because that would require that the page b
On 12 April 2017 at 10:16, Tom Marchant <
000a2a8c2020-dmarc-requ...@listserv.ua.edu> wrote:
[DB2]
> So, if it thinks it would be faster to read the record from DASD than for
> MVS to page in the buffer page(s) containing the record, it will read the
> record into different pages that have not
On 04/12/2017 10:16 AM, Paul Gilmartin wrote:
> On Wed, 12 Apr 2017 09:50:44 -0500, Joel C. Ewing wrote:
>> GETMAIN returns a success indication based purely on whether virtual
>> storage is available to the address space within the REGION size
>> constrains.
>>
> Does it not check for available pa
ibmsysp...@ibm-sys-prog.com (Avram Friedman) writes:
> While they do not grow in in perfect lock step The presence of Big ass
> memory comes with big ass dasd volumes (these are the technical terms
> of course) Do you know 3350's and 2314s were once used as paging
> devices? For that matter do you
On Wed, 12 Apr 2017 09:50:44 -0500, Joel C. Ewing wrote:
>
>GETMAIN returns a success indication based purely on whether virtual
>storage is available to the address space within the REGION size
>constrains.
>
Does it not check for available paging space? Does this imply that your
job and my job
On 04/11/2017 05:41 PM, Paul Gilmartin wrote:
> On Tue, 11 Apr 2017 16:45:10 -0500, Greg Dyck wrote:
>
>> On 4/11/2017 3:26 PM, Paul Gilmartin wrote:
>>> My understanding, ancient, probably outdated, and certainly naive is that
>>> there is little communication between GETMAIN/FREEMAIN and the pagi
On Wed, 12 Apr 2017 13:08:32 +, Vernooij, Kees wrote:
>
>> -Original Message-
>> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On
>> Behalf Of Tom Marchant
>> Sent: 12 April, 2017 15:03
>> To: IBM-MAIN@LISTSERV.UA.EDU
>>
While they do not grow in in perfect lock step
The presence of Big ass memory comes with big ass dasd volumes
(these are the technical terms of course)
Do you know 3350's and 2314s were once used as paging devices?
For that matter do you no the number 2314 was chosen as the # for a model of
disk d
> -Original Message-
> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On
> Behalf Of Tom Marchant
> Sent: 12 April, 2017 15:03
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: Re: Paging subsystems in the era of bigass memory
>
> On Wed, 12
On Wed, 12 Apr 2017 06:28:05 +, Vernooij, Kees wrote:
>From here, there the story still goes on IIRC: if DB2 again needs
>the data, it would be paged in in any normal task. However, DB2
>is more intelligent: it keeps track of how long it takes to page-in
>the page or read it again from disk
On Wed, 12 Apr 2017 06:18:29 +, Vernooij, Kees wrote:
>The advantage of not freeing the aux slot was that a page could
>be paged out without I/O if it had not been changed. Somewhat
>the opposite op page reclaim. Freeing it after it has been changed
>is of course a 100% useful reclaim of au
> -Original Message-
> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On
> Behalf Of Blaicher, Christopher Y.
> Sent: 11 April, 2017 21:25
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: Re: Paging subsystems in the era of bigass memory
>
> It
> -Original Message-
> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On
> Behalf Of Greg Dyck
> Sent: 11 April, 2017 23:39
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: Re: Paging subsystems in the era of bigass memory
>
> On 4/11/2017 1:46 PM
>
> But like any design tradeoff, there are drawbacks as well, and with
> real
> storage
> less expensive and more plentiful, you can have a lot more virtual pages
> consuming both an aux slot and a real frame. There has been some
> thought given to changing things so that we always free the a
l...@garlic.com (Anne & Lynn Wheeler) writes:
> The "dup" issue was if aggregate 3880-11 wasn't much larger than
> processor memory, then nearly every page in 3880-11 would also in
> processor memory. The converse if a page was needed not in processor
> memory, then it would unlikely be in 3880-11
> > If a virtual page is not 'getmain assigned' by VSM it will never be
backed
> > by a real frame by RSM and an 0C4-11 will occur. When all virtual
storage
> > on a page is freed VSM will return the allocated AUX slot and real
frame,
> > if either have been allocated, and reset the 'getmain as
> What about the other side? Will GETMAIN return indication of success
> only if the requested page slots can be committed?
There is no consideration of aux slot availability when virtual
storage is being allocated. There used to be some capability to
reserve aux slots when an address space wa
>Many moons ago code was implemented in ASM and RSM to slowly reclaim ASM
>page slots for virtual pages that were changed in real storage. I have
>vague memories of this functionality later being disabled for some
>technical concern, but can't remember what it was.
Slot Scavenger was introdu
t...@harminc.net (Tony Harminc) writes:
> Not quite sure what you're saying. The old, constrained-memory
> technique was usually to issue a variable (Vx) GETMAIN, specifying the
> minimum required size as the low bound, and the maximum useful as the
> high. Then the system returns the actual amount
On Tue, 11 Apr 2017 16:45:10 -0500, Greg Dyck wrote:
>On 4/11/2017 3:26 PM, Paul Gilmartin wrote:
>> My understanding, ancient, probably outdated, and certainly naive is that
>> there is little communication between GETMAIN/FREEMAIN and the paging
>> subsystem. If a program touches a page that wa
On 11 April 2017 at 17:45, Greg Dyck wrote:
> If a virtual page is not 'getmain assigned' by VSM it will never be backed
> by a real frame by RSM and an 0C4-11 will occur. When all virtual storage
> on a page is freed VSM will return the allocated AUX slot and real frame,
> if either have been a
On 4/11/2017 3:26 PM, Paul Gilmartin wrote:
My understanding, ancient, probably outdated, and certainly naive is that
there is little communication between GETMAIN/FREEMAIN and the paging
subsystem. If a program touches a page that was never GETMAINed no error
occurs; simply a page slot is alloc
On 4/11/2017 1:46 PM, Jesse 1 Robinson wrote:
Part of the problem, I learned some time back at SHARE, is that there is no
mechanism to 'reclaim' page slots that no longer need to remain on disk. Once
storage gets paged out, it sits there like a sandbag until the owning task is
stopped. Contras
On 4/11/2017 2:24 PM, Blaicher, Christopher Y. wrote:
It has been a while since I worked on DB2, but it is sounding like your buffer
pools are too big.
With large memory systems everyone should have all of the production
(and, ideally, test systems too) buffer pools define with PGFIX(YES)
sp
On 11 April 2017 at 16:26, Paul Gilmartin <
000433f07816-dmarc-requ...@listserv.ua.edu> wrote:
> If a program touches a page that was never GETMAINed no error
> occurs; simply a page slot is allocated up to the limit of the REGION
> parameter. Conversely, on FREEMAIN the page slots are not re
On 2017-04-11, at 12:47, Jesse 1 Robinson wrote:
>
> Part of the problem, I learned some time back at SHARE, is that there is no
> mechanism to 'reclaim' page slots that no longer need to remain on disk. Once
> storage gets paged out, it sits there like a sandbag until the owning task is
> stop
efined of 7740M
Carmen
From: "Christopher Y. Blaicher"
To: IBM-MAIN@LISTSERV.UA.EDU
Sent: Tuesday, April 11, 2017 2:24:54 PM
Subject: Re: Paging subsystems in the era of bigass memory
It has been a while since I worked on DB2, but it is sounding like your buffer
pools are too b
me Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf
Of Jesse 1 Robinson
Sent: Tuesday, April 11, 2017 2:47 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Paging subsystems in the era of bigass memory
The problem we face is 'paging creep'. Right after IPL, systems show 0% ASM
usage
On 4/11/2017 8:54 AM, Doug Henry wrote:
Hi Tom,
We have a pair of SCM cards (so in case one fails). Each card has 1.4 Terabytes
of memory.
For an lpar that has 524GB online and the SCM online is 384G. As for the cost
I don't really know.
ISTR a pair of flash cards is somewhere around $150K
Re: Paging subsystems in the era of bigass memory
On 4/11/2017 2:46 PM, Jesse 1 Robinson wrote:
> The problem we face is 'paging creep'. Right after IPL, systems show 0% ASM
> usage for some period of time. Then usage starts to creep up until we get
> warnings, then eventually hit th
7;t going fast enough.
-Original Message-
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf
Of Tom Conley
Sent: Tuesday, April 11, 2017 11:52 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: EXTERNAL: Re: Paging subsystems in the era of bigass memory
On 4/11/2017 2:46
On 4/11/2017 2:46 PM, Jesse 1 Robinson wrote:
The problem we face is 'paging creep'. Right after IPL, systems show 0% ASM
usage for some period of time. Then usage starts to creep up until we get
warnings, then eventually hit the no-more-SVC-dumps condition. Adding memory to
an LPAR slows the
6132 Office ⇐=== NEW
robin...@sce.com
-Original Message-
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf
Of Tom Conley
Sent: Tuesday, April 11, 2017 11:13 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: (External):Re: Paging subsystems in the era of bigass memory
On 4/11/2017 1:16 PM, van der Grijn, Bart , B wrote:
Largest LPARs we have are about 200GB with 6 MOD27 per LPAR. They all run DB2
for distributed workloads plus some application specific subsystems.
The two busiest of those LPARs each run one DB2 member of the same DB2 data
sharing group with
Largest LPARs we have are about 200GB with 6 MOD27 per LPAR. They all run DB2
for distributed workloads plus some application specific subsystems.
The two busiest of those LPARs each run one DB2 member of the same DB2 data
sharing group with a frame occupancy of about 39M.
Next to no paging.
Ba
Don't forget about PAGTOTL in SYS1.PARMLIB(IEASYS00).
Default is 40. Extra slots reserve ESQA, so don't be overly generous.
HTH,
I had the total number of pages allocated and available in the current paging
subsystem, so I calculated the available pages with 22 more mod-9's and then
divided t
On Tue, 11 Apr 2017 12:36:10 -0400, Tom Conley
wrote:
>I had the total number of pages allocated and available in the current
>paging subsystem, so I calculated the available pages with 22 more
>mod-9's and then divided the allocated pages into the new total pages
>available. I plan to do PAGEA
On 4/11/2017 12:03 PM, Lizette Koehler wrote:
Tom
How did you determine you needed 22 more MOD9s. Is there a formula you used?
Lizette
Hi Lizette,
I had the total number of pages allocated and available in the current
paging subsystem, so I calculated the available pages with 22 more
mo
On Tue, 11 Apr 2017 10:46:40 -0400, Pinnacle wrote:
>Gone are the halcyon days when we could run an LPAR with three mod-3's
>as the local paging subsystem. With today's large memory sizes, I'm
>faced with having to completely rethink my paging subsystems. I've
>currently got a 133GB LPAR with 1
Tom
How did you determine you needed 22 more MOD9s. Is there a formula you used?
Lizette
> -Original Message-
> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On
> Behalf Of Pinnacle
> Sent: Tuesday, April 11, 2017 7:47 AM
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject
On Tue, 11 Apr 2017 11:31:32 -0400, Tom Conley
wrote:
>On 4/11/2017 11:20 AM, Doug Henry wrote:
>> On Tue, 11 Apr 2017 10:46:40 -0400, Pinnacle
>> wrote:
>>
>> I wondered what the rest of
>>> you are doing with your paging subsystems in the era of bigass memory sizes.
>>>
>>> Regards,
>>> Tom
On 4/11/2017 11:20 AM, Doug Henry wrote:
On Tue, 11 Apr 2017 10:46:40 -0400, Pinnacle wrote:
I wondered what the rest of
you are doing with your paging subsystems in the era of bigass memory sizes.
Regards,
Tom Conley
Hi Tom,
We use Storage Class Memory to solve the problem.
Doug Henry
USB
On Tue, 11 Apr 2017 10:46:40 -0400, Pinnacle wrote:
I wondered what the rest of
>you are doing with your paging subsystems in the era of bigass memory sizes.
>
>Regards,
>Tom Conley
Hi Tom,
We use Storage Class Memory to solve the problem.
Doug Henry
USBANK
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