Shmmax and shmall OS param

What is the impact for Oracle database when my shmmax and shmall parameters will be set several times greater that recommended value? I try to find on google and metalink, bo no results at the moment.

It is still advisable to set this parameter as recommended to avoid impacting database performance and overall functionality, as well as unexpected operating system behavior. If SHMMAX is set too large or too small, memory errors may be received when starting or running the database.
Pls. check the following documents:
Health Check Alert: Set SHMMAX greater than or equal to the recommended minimum value [ID 957520.1]
Maximum SHMMAX values for Linux x86 and x86-64 [ID 567506.1]
TECH: Unix Semaphores and Shared Memory Explained [ID 15566.1]

Similar Messages

How to know the right value for SHMMAX and SHMALL for ia64 memory 32Gb

Dear all,
I want to install Oracle database 10g R2 on RHEL 5 ia64.
Here the server specification :
Proc : itanium64 ( montecito )
Mem : 32Gb
# getconf PAGE_SIZE = 16384
Metalink says, that SHMMAX should be half of physical memory and SHMALL = SHMMAX / PAGE_SIZE.
kernel.shmmax = 17179869184
kernel.shmall = 1048576
My Question is this is right value for SHMMAX and SHMALL on my server..??
Thank you

if shmmax is half the ram then what should be sga
sga size should anyhow should be less then shmmax ,means we cannot increase sga size more than half the ram
then how ROT for SGA that should be 70% of RAM hold good

Optimal value for shmmax and shmall

Hi Experts,
Am new to the database administration side. Need help/suggestions from you all. My requirement is narrated below:
I was going the kernel parameter for oracle 10gr2. But I have a doubt the following two parameters.
kernel.shmall=2097152 (Default)
kernel.shmmax=2147483648 (Default)
Also I know that this is the recommended value for these two parameters. But just want to check if I have physical RAM of 4GB then what should be the optimal value for these parameter.
Also can anyone suggest how to set the optimal value for these parameter.
Thanks

You can always set to the "Install" size and after it completes reduce them. You can move them down 25 to 30 percent in most cases.
The default size for SHMALL in RHEL 3/4 and 2.1 is 2097152 which is also Oracle's recommended minimum setting for 9i and 10g on x86 and x86-64 platforms. In most cases this setting should be sufficient since it means that the total amount of shared memory available on the system is 2097152*4096 bytes (shmall*PAGE_SIZE) which is 8 GB. PAGE_SIZE is usually 4096 bytes unless you use Big Pages or Huge Pages which supports the configuration of larger memory pages.
SHMMAX should not exceed 4294967295 on a 32-bit system. On x86-64 platforms, SHMMAX can be much larger than 4GB since the virtual address space is not limited by 32 bits.
If SHMMAX is too small, you can get error messages like :
ORA-27123
I almost always go with the recommended settings even on tiny 1GB systems.
With a 4GB system these probably are not worth changing.
Best Regards
mseberg
Edited by: mseberg on Jul 13, 2011 5:21 AM

SHMMAX and UNLIMIT

How do you set the Kernel parameters for SHMMAX, SHMMIN, ... and
I'm also getting an alert about UNLIMIT needing to be 2113674.
Can anyone help?
Thanks
Jon
null

For Slakware, probably similiar with other releases:
(I'm not at my Linux box so I'm wingin' this reply)
You essentially have to change the setting in some header (.h)
files in the kernel source directories and re-compile the kernel.
cd to /kernel/src and (or /src/kernel ?)
find . -name "*.h" -exec grep -i shmmax {} \;
I think the settings are in a header called shmem.h or something
along those lines (sh*.h). You'll have to poke around to find
them.
I ignored the param mods and have been running with no problem.
Earl
Jon Stauffer (guest) wrote:
: How do you set the Kernel parameters for SHMMAX, SHMMIN, ...
and
: I'm also getting an alert about UNLIMIT needing to be 2113674.
: Can anyone help?
: Thanks
: Jon
null

Shmmax and 11g

I am investigating 11g installation and config on an HP x86_64 Redhat server. The Oracle Validated RPM adjusted shmmax in sysctl.conf to 4T. This corresponds to what is seen at
http://linux.oracle.com/pls/apex/f?p=102:2:1240694098498237::NO::P2_VC_ID:471
With this setting and a suitable memory_max_target parameter, the database produced "unable to attach to shared memory segment" and similar errors after some time under load. The error does not appear with more traditional shmmax settings of 1/2 RAM or similar.
Am I missing something? Is 4T correct and without side effects? Am I missing something?

mosborn wrote:
I am investigating 11g installation and config on an HP x86_64 Redhat server. The Oracle Validated RPM adjusted shmmax in sysctl.conf to 4T. This corresponds to what is seen at
http://linux.oracle.com/pls/apex/f?p=102:2:1240694098498237::NO::P2_VC_ID:471
With this setting and a suitable memory_max_target parameter, the database produced "unable to attach to shared memory segment" and similar errors after some time under load. The error does not appear with more traditional shmmax settings of 1/2 RAM or similar.
Am I missing something? Is 4T correct and without side effects? Am I missing something?In your context ... what does suitable memory_max_target mean.
Generally i would wish the sum (memory_max (or memory_max_target if greater)) for all active instances to be less (and prehaps well less) than 3/4 of my physical ram under virtually all circumstances.
Having that 4T seems excessive .... 64G or so would be well enough over the top for most servers.
Confirm also your running 64bit and that your not doing hugepages or something.
I feel like I have just stated some obvious checks, and apologies if you've already done this.
Rgds - bigdelboy.

Using JDBC ? Style Parameters and Oracle Style :param on view objects

can i use :0 style on predicate side of a sql statement
example
===========================================================
select nvl(:0, null) from dual
===========================================================
After some test for me only work using ? style.
The ? style cause me problem on my already creaded master details view objects
Any help on this
Best Regards

Frank tnx for repply
My problems is , when i use parameters on functions like decode
===================================================
SELECT decode(:0,'VALOR1', 'VALOR1','SINVALOR') VALOR,
       Dept.DEPTNO,
FROM DEPT Dept
and
SELECT decode(:0,'VALOR1', 'VALOR1','SINVALOR') VALOR,
       Emp.EMPNO,
       Emp.DEPTNO
FROM EMP Emp===================================================
on a view object that is detail view object (departments vo -> employees vo)
and have a view link EmpsByDeptViewLink
the parameter of my view link SQL dont work (in my case :1) <-param of SQL view link
In my vo :0 is my first parameter, :1 of my view link is my second parameter,
but when i access my EmpsByDept.do ADF page and set
    ViewObject vo = getDeptView1();
    vo.setWhereClause("DEPTNO = :0");
    vo.setWhereClauseParam(0,"VALOR2");
    vo.setWhereClauseParam(1,"10");
    vo.executeQuery();
    ViewObject vo1 = getEmpView1();
    vo1.setWhereClause("EMPNO = :1");
    vo1.setWhereClauseParam(0,"VALOR1");
    vo1.executeQuery();its doesnot work.
I need to do some aditional steps to parameter of my view link SQL work?
Also i has uploaded a TestCase on http://www.geocities.com/mroseroc/ScottADFTest.zip
Errors from my Jdeveloper Debug level are:
=======================================================
SELECT * FROM (SELECT decode(:0,'VALOR1', 'VALOR1','SINVALOR') VALOR,
       Emp.EMPNO,
       Emp.ENAME,
       Emp.JOB,
       Emp.MGR,
       Emp.HIREDATE,
       Emp.SAL,
       Emp.COMM,
       Emp.DEPTNO
FROM EMP Emp) QRSLT WHERE (EMPNO = :1)
06/04/26 21:55:03 [915] Bind params for ViewObject: EmpView1
06/04/26 21:55:03 [916] Binding param 1: VALOR1
06/04/26 21:55:03 [917] ViewObject: EmpView1 close single-use prepared tatements
06/04/26 21:55:03 [918] QueryCollection.executeQuery failed...
06/04/26 21:55:03 [919] java.sql.SQLException: Missing parameter IN o OUT on index:: 2=======================================================
(EMPNO = :1) <- this value is never passed

Rendering hyperlinks using h:commanLink and setting f:param values

dear friends,
I want to render some hyperlinks with <h:commandLink>
and then I want to set the <f:params > value of each hyperlink
all those things are stored in a ArrayList whose values depends on
parameter that I want to pass through another JSF or JSP page
I have alredy tried combination of JSTL and JSF tags it is working
properly
but there is one problem when page loads for the first time
no hyperlink gets renderd on page after refreshing page it shows all those hyperlink s
if anybody of you is getting my question and know wht to do in this situation please guide me abt the same
By the way Happy New Year to All Java Technology Lovers

Actually, in your original post you used ExternalContext.getRequestMap(), not ExternalContext.getRequestParameterMap(). They both exist and there is a difference.

How to open a report without refreshing and sending some param value

we have a summary report which has links to the detail report.For example the summary report has data like
Countries        EmployeeCount
UK                5
US                6
China                7
Total                18
When we click on China it must show the Employees whose country is China (detail report) When we click on Total it shows Employee of all countries UK,US,China...
Now when we run the summary report online say at 5:10 it shows the staus of countries at 5:10.Say the report is open while an employee of china is moved from China to Uk.But when we open the detail report it shows China count as 6 which should actually be 7 according to the summary report run time.
A similar problem exist when we schedule the report .When we schedule the summary report and detail report at same time..And then try to open the scheduled instance of detail report from summary scheduled instance ,It only works fine if no parameter is passed to openDocument url.
Say suppose I click China on summary report the Value China should be passed to detail report as Country.But whenever we try to open a scheduled instance of Detail Report along with a parameter using openDocument Url.It refreshes the whole data even though refresh is set to 'N'.So the scheduled data is lost..Even if we try for Drillfilters in detail Report we cannot set it at runtime using open document Url.

Mihail - I detailed a couple of approaches here: Re: Application Link
Scott

Setting/Getting Parameter Values BEFORE and AFTER the param window loads

Hi there. My name is William Sanchez. I posted this question on Brian Wheadon's blog because I'm not sure that what we're trying to accomplish can be currently done with 2008 Crystal Report Viewer and was wondering if a future version will support this, or if we're just missing something. I've searched through the SDK and API and can't seem to find a solution. Here's what we're trying to accomplish
In a nutsheel: we think we need to hook into Crystal Report Viewer's parameter window from our WPF app.
What we need to do is to be able to pass a set of default values to our parameters AND, after that's done programmatically, still display the parameter window for the report. Currently, however, after you do:
parameterFieldDefinition.ApplyCurrentValues(currentParameterValues);
it's as if Crystal says: Ok, we got the value, there's no need to show the parameter window anymore. This makes sense, but we need to still be able to show the parameter window to the user because all we did (from our point of view) is to pass in a default "choice". If we were to call ApplyDefaultValues() instead, the actual choices for the parameter are overriden. We basically want to make a default choice for the user from the allowed values for that parameter. But we want to still present the parameter window with the default choice already selected, plus all the other choices available for that parameter. If the crystal report has parameter1 set to false as default, we might want to programmatically set it to true, but still show false as an option on the parameter window.
Part 2 of what we'd like to accomplish is that after the user changes any of the parameter values, and clicks OK to view the report, we'd like to catch the new parameter values in code to do something with them.
This is why we're thinking of hooking into the parameter window so that we can tell it what we want both BEFORE it loads and AFTER the user is done...just like we can hook into the CrystalReportViewer refresh button like this:
CrystalReportsViewer.ReportRefresh += new CrystalDecisions.Windows.Forms.RefreshEventHandler(CrystalReportsViewer_ReportRefresh);
Our app is a WPF C# .NET 3.5 desktop application. Any assistance or direction will surely be appreciated.
Kinds Regards,
William Sanchez
Edited by: wsanchez78 on Mar 31, 2010 1:20 AM

Good day Ted, thanks for your reply.
I did try Parameter.Default value, but what it does is as I mentioned above. If I have Parameter1 as a boolean, with possible values of true and false, if I set Paramter1.Default = true, the parameter window does come up, but it removed the false option from the drop down. So this is not a way to pick one of the various values for Parameter1, but to default it to only one of the values. It's close to what we need, but not fully.
Also, what are your thoughts about getting the parameter values after the user has made their changes to the CrystalReportViewer parameter window and click OK to pass them to the report. How can we programmatically get those new values?

Abap mapping and operation mapping param

Hi All,
I have a problem with retrive value of export parameter in operation mapping by abap mapping class.
standard parameter of abpa mapping class method that execute it contains param that ref to IF_MAPPING_PARAMETERS. So i belive by this class using method PARAMETERS->GET_STRING( 'P_IDOC_NR' ), but it dosen't works.
Any idea
Regards
M.

I have not seen anything in online help that gives the impression that you can use parameters in ABAP mapping.
So I suppose that this does not work at all.
Maybe you could use this approach:
/people/peter.glas3/blog/2010/09/08/pi-parameterized-xslt--a-flexible-alternative

JCO /RFC prog and SNC : snc params ignored

Hi all ,
I've written a simple JCO prog to connect to a SNC enabled R/3 system. It does this but skips the SNC parameters ..I know this as I can put in some false data
and it still works (R/3 system excepts insecure RFC) :
client = JCO.createClient("xxx", //Client
                           "YYY", //User
                           "EN", //Language
                          "zzzz", //password
                           "host1", //hostname
                           "nn" ) ; //sysnr
client.setProperty("jco.client.snc_mode", "1");
etc...
Why is it ignoring the snc_mode ?
Regards
Daniel

Hello Daniel,
perhaps you try to connect via a properties file as described in the TutorialConnect2.java coming with JCo in the demo directory. Then you can use this Parameters:
jco.client.snc_mode=1
jco.client.snc_partnername=
jco.client.snc_lib=
Or have you found another solution to make your RFC connection encrypted by SNC?
Regards
Gregor

What is shmmax?

Dear All,
what is shmmax?
According to my knowledge,
SHMMAX is the memory allocated for oracle from OS .
Within that SHMMAX only we need to use the oracle memory components?
where and how to view the SHMMAX parameter?
Regards,
Db

DB wrote:
Dear All,
what is shmmax?
According to my knowledge,
SHMMAX is the memory allocated for oracle from OS .
Within that SHMMAX only we need to use the oracle memory components?
where and how to view the SHMMAX parameter?
Regards,
DbRefer to this
http://padmavyuha.blogspot.com/2010/12/configuring-shmmax-and-shmall-for.html

HugePages and Linux

Hi,
We have a linux machine with 128 GB of RAM, there are 3 different databases running on this machine with 50/17GB, 30/10GB and 30/10GB of SGA/PGA individually. What impact is going to be there if I enable HugePages for these Databases ? I know I can enable large pages usage individually on each database with the usage of use_large_pages parameter, enabling or disabling this will allow the usage of Hugepages. What I want to know is what if I enable HugePages for all of the 3 databases ? what impact is going to be there ? will the machine suffer from OS paging/swapping ?
Please give your expert opinion.
Regards
Shabbar

https://www.youtube.com/watch?v=DK4JjRRAxTU
http://www.oracle.com/technetwork/articles/servers-storage-dev/hugepages-2099009.html
Also note the following:
Transparent Huge Pages - Is there a need to disable them?
Get confused about how to calculate SHMMAX and SHMALL on Linux.
11.2 Configuring HugePages for Oracle Database

ORA-27123 unable to attach shared memory segment

Running oracle 8.1.5.0.0 on Redhat 6.0 with kernel 2.2.12, I keep getting the error ORA-27123 unable to attach shared memory segment when trying to startup and instance with an SGA > 150 MB or so. I have modified the shmmax and shmall kernel parameters via the /proc/sys interface. The relevant output of ipcs -l is below:
------ Shared Memory Limits --------
max number of segments = 128
max seg size (kbytes) = 976562
max total shared memory (kbytes) = 16777216
min seg size (bytes) = 1
This system has 2gb of physical memory and is doing nothing except oracle.
I changed the shmmax and shmall parameters after the instance was created, was their something I needed to do to inform Oracle of the changes?

High JW,
i had the same problem on my installation.
The solution is written in the Oracle8i Administrator Refernece on page 1-26 "Relocating the SGA"
a) determine the valid adress range for Shared Memory with:
$ tstshm
in the output Lowest & Highest SHM indicate the valid adress range
b) run genksms to generate the file ksms.s
$ cd $ORACLE_HOME/rdbms/lib
$ $ORACLE_HOME/bin/genksms -b "sga_beginn_adress" > ksms.s
c) shut down any instance
d) rebuilt the oracle exe in $ORACLE_HOME/rdbms/lib
$ make -f ins_rdbms.mk ksms.o
$ make -f ins_rdbms.mk ioracle
the result is a new oracle kernel that loads the SGA at the adress specified in "sga_beginn_adress".
regards
Gerhard

XE11: Calculating shmall and shmmax for 64b linux

Hello,
installing XE11 on a 64b linux gives me a message like 'unexpected nummer' or '
'expect a integer value'
shmall and shmmax is set to
kernel.shmall = 1152921504606846720
kernel.shmmax = 18446744073709551615
from the os.
shmmax seems to big for calculating:
This is what the installation does:
shmmax=`cat /proc/sys/kernel/shmmax`
changeshmmax=no
if [ $shmmax -lt 4294967295 ]
then
    shmmax=4294967295
    changeshmmax=yes
fi
if [ "$changeshmmax" != "no" ]
then
    /sbin/sysctl -w kernel.shmmax="4294967295" >> /etc/sysctl.conf
fi
How can i calcutlate and set correct values for shmall and shmmax for XE11?
OS is openSUSE 13.1 64bit, machine has 4GB memory, but it seems to be the same in all 64bit
distributions.
Best regards.

Hello again,
this is allocated on most distributions with kernel 3.x in
/boot/sysctl.conf-<kernel-version>:
# Generated file - do not edit.
# Disable the hung task timer by default. (bnc#552820)
kernel.hung_task_timeout_secs = 0
# Increase defaults for IPC (bnc#146656)
kernel.msgmax = 65536
kernel.msgmnb = 65536
kernel.sem = 250 256000 32 1024
# Increase defaults for IPC (bnc#146656) (64-bit, 4k pages)
kernel.shmmax = 0xffffffffffffffff
# SHMALL = SHMMAX/PAGE_SIZE*(SHMMNI/16)
kernel.shmall = 0x0fffffffffffff00
But i cannot access the bugzilla entry bnc#146656
Best regards

Shmmax and shmall OS param

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