What is shared memory?

Similar Questions

• Satellite Pro C660 - 21 d - how to change the shared memory graphic value?

  My dxdiag screen says I have almost 1700 MB of video memory, but when I try to use this memory on games these games can use 256 MB...

  I tried to change settings in the BIOS, but it does not have this setting, do not know what else could cause this problem?

  Hello

  This could be confusing, but this isn't a problem.
  Shared memory is controlled by the graphics driver and the driver affects the part of the main memory to the memory of the graphics card ONLY if its required by a running application.

  The Dxdiag shows you how much RAM could be shared and value of memory in the quizzes you shared memory which is used and who is in the game right now.

• Satellite P300-156 - ATI 3470 256 MB - low shared memory

  I need solution.
  I see now my system properties 4 GB of ram available.
  2 months ago I had only 3 GB of free because 1 GB GB for like shared memory graphics card.

  Can anyone help me solve this problem, because after this update problem, I've got 4.5 system score and now I have only 4.
  Where is the problem, something with drivers or what? Sorry for the English.

  Need help to solve this problem

  Hello

  Shared memory cannot be assigned manually.
  Everything is controlled by the graphics card driver it assigns and automatically share memory to graphics card memory

  Memory will be affected ONLY if it of necessary it means that if running applications n t need more graphics memory then the graphics card driver not be assigned more than necessary!

• HugePages shared memory

  Hi there again,

  Sorry for this question about hugepages.

  Does hugepage allways shared for the SGA memory? Does I don't no need of knowledge about shmax and/proc/meminfo-> shm

  cat/proc/meminfo

  Shmem: 476 KB

  Thanks I m stuck

  * T

  total max shared memory (KB) = 4611686018427386880... can you convert GB? can you check with your size of ram (deicide if possible or not)

  when its comes by default, sles kernel, you have right to set up correctly.

  What is the Hugepagesize? I hope its 2 k, then it is mapped with 7680 == 15 GB

  (a) If you want to keep 15 GB (you must decide what is best for your environment) every thing is acceptable up to your limit of RAM (opt for 60% of RAM) total

  (b) higepage size is 2 k so 15 GB/2 k corresponds to 7680 pages (mapped to vm.nr_hugepages)

  (c) Please change SHMMAX and SHMALL correctly (refer to the oracle documentation)

  (d) update under settings

  (HugePages * Hugepagesize).
  == 7680 * 2 k

  soft memlock Oracle 15728640

  15728640 Oracle hard memlock

  It may be useful

  -Pavan Kumar N

• Setting the shared memory size linux

  Hello
  I'm a bit confused on the parameters of the kernel, can you please share your views on this one please.
  Shared for the tt in the linux kernel memory is calculated as follows:
  Shared mem = perm size size temp + journal + fresh size generals 7 MB
  
  but when I look at the linux sysctl.conf, I saw that there is a great value for sharing memory setting (default) as ~ 68 GB, then I think that I should not override/decrease this value. What is your opinion? Setting the value default (68 GB) helps my DB behave badly? Or by assigning the value calculated as in the equation makes them much faster?
  
  # Control the maximum shared segment size, in bytes
  kernel.shmmax = 68719476736
  kernel.SEM = 250 32000 100 100
  
  # Control the maximum number of shared memory pages segments
  kernel.shmall = 4294967296
  
  Thank you very much.

  The shmmax kernel parameter simply sets a limit on the maximum size of a shared memory segment individual. It has no direct effect on performance. In general, it should be set large enough to allow the largest shared memory segment you need to create but smaller then the amount of physical memory in the machine. Shmall parameter sets a limit of large system on the total amount of shared memory (all active segments added) can be allocated. It must be also, in General, lower then the [physical memory on the computer.

  If one is defined on more memory in the machine is not an immediate problem. However, in this case, it is possible to create shared memory that is larger than the physical memory of the system (as far as adequate swap space is configured), and if this happens then the overall performance of the system will be affected, probably seriously.

  Thus, work on what you need and set accordingly.

  Chris

• Shared memory when importing error

  Aloha!
  
  I did an import with this setting:
  

  schemas = directory = schema_name impdp system transform dir = segment_attributes:n:table dumpfile dump101K.dmp logfile = log101K.log =

  import ended prematurely due to this error.
  

  ORA-04031: unable to allocate 3896 bytes of shared memory ('shared pool', "select case when (bitand (u.s...", "sga heap (1.0) ', ' batch object kglsim")) ")
  ORA-04031: unable to allocate 4064 bytes of shared memory ('shared pool', "ALTER SESSION SET EVENTS 10...", "bunch of sga (1,0) ', 'heap kglsim')

  when I tried to log in as sys and change the setting of the memory of my instance using this script.
  

  ALTER SYSTEM SET MEMORY_MAX_TARGET = G 1 SCOPE = SPFILE
  ALTER SYSTEM SET MEMORY_TARGET = G 1 SCOPE = SPFILE
  ALTER SYSTEM SET SGA_TARGET = 0 SCOPE = SPFILE

  I was invited by this error:
  

  ERROR on line 1:
  ORA-01012: not connected
  Process ID: 0
  Session IDs: serial number 0: 0

  when I try to shut down the instance, I have this error:
  

  SQL > shutdown immediate
  ORA-04031: unable to allocate 4064 bytes of shared memory ('shared pool', 'select host, username, password,... (', ' sga heap (1.0) ', 'heap kglsim')

  side perform a physical reboot. What else can I do to fix such errors?
  
  Thanks in advance.
  
  Kind regards
  Hades

  Side perform a physical reboot. What else can I do to fix such errors?

  Once again delivering under cmd with size 2G and take the database restarts.

  ALTER SYSTEM SET MEMORY_MAX_TARGET = 2G SCOPE = SPFILE
  ALTER SYSTEM SET MEMORY_TARGET = 2G SCOPE = SPFILE

• Question about shared memory

  Hello!

  I have a virtual machine that is configured with 1 GB of RAM and installed with Windows Server 2003. Shortly after starting the virtual machine, the info of the allocation of resources on the memory usage indicates the following:

  

  While the Task Manager Windows VM shows the following:

  

  While the use of the memory of the VM on the host is only 264 MB, why the use of the memory of comments displays 787 MB shared memory? The virtual machine is the only VM running on this host. If I understand correctly, "Shared memory" would theoretically show the amount of memory shared with other virtual machines on this host. For example, let's say I had two W2K3 VMs on that host with 1 GB of RAM each, the counter shared memory would report to the amount of memory that is the same for both these virtual machines and so physically shared. However, since there is no other virtual computer running on this host I don't really understand why he reports 787 MB!  It seems to me that the value of the shared memory is unused memory in fact (since the task inside the guest Manager reports only about 150 MB use and the virtual machine does not seem to consume the 264 MB mentioned on the host).

  Any ideas what I'm missing? Thank you!

  As you say

  • The virtual computer is configured with 1024 MB of RAM

  • The private memory usage is 237 MB

  • Shared memory is 787 MB

  All Windows VMs zero start pages is that they fill all memory with zeros. So VMKernel identifies all pages from scratch can be shared to one. In your scenario THAT VM wrote zeors 1024Mo and out of which 787 MB is shared and still 237 is used which further can be shared. 787 MB shared memory means that it the memory saved with page sharing and memory amount can be used by other processes.

  I hope this helps.

  Thank you.

• ORA-27100: shared memory realm already exists

  What is the reference, cannot start db?
  
  SQL > connect sys / * as sysdba;
  Connect to an instance is idle.
  SQL > startup;
  ORA-27100: shared memory realm already exists
  SQL > startup pfile='C:\Oracle\admin\clin\pfile\init.ora.226201215818 '
  ORA-27100: shared memory realm already exists
  SQL >
  
  I even followed it
  http://www.DBA-Oracle.com/t_ora_27100_shared_memory_realm_already_exists.htm
  
  Log queue alerts
  ORACLE V10.2.0.4.0 - Production vsnsta = 0
  vsnsql = 14 vsnxtr = 3
  Windows NT Version V5.2 Service Pack 2
  CPU: 2 - type 586, 2 physical cores
  Process affinity: 0x00000000
  Memory (success/Total): Ph: 2505 M / 4095 M, Ph + FCP: 3982 M / 5971 M, GOES: 1924M / 2047 M
  Wed Mar 28 16:43:54 2012
  Starting ORACLE instance (normal)
  Wed Mar 28 16:44:31 2012
  Starting ORACLE instance (normal)
  Wed Mar 28 16:45:31 2012
  Starting ORACLE instance (normal)
  
  Published by: DBA2011 on March 28, 2012 15:48

  What parameters of memory that you use for your instance?

  Your sga_max_size is greater than 2 GB?

  In this case, you can see the details on how to solve this problem on MyOracleSupport Note ID 370469.1 - "startup fails with ORA-27100 after restart the Windows Service.

  Kind regards.

• Oracle not available, shared memory realm does not exist

  Hello
  
  I have problem during the installation of XE on Windows 2003 R2 SP 2 Enterprise edition. I have uninstall oracle xe and still the same result. Finally, I uninstall the windows and start all over again, surprisingly the always the same result. FYI, we have normally no problem during installation because it is part of our system, we sell to our customers who require Oracle xe. It is the first time we have seen this issue.
  
  ORA-01034: Oracle not available
  ORA-27101: shared memory realm does not exist.
  
  Oracle XE and Auditor services is started in windows services.
  
  If we try to start the message occurred.
  
  SQL > connect sysdba virtue
  
  Connect to an instance is idle.
  SQL > startup
  ORA-44412: setting memory XE edition invalid or unspecified
  SQL >
  
  I can send you the journal oracle_xe, ora init and OpsBuildAll.log to create the database.
  
  When compared with the installation of work, we have seen that the size of the oraclexe folder is less, it's just 233 MB while the work is beyond 1 GB. After investigation, discovered that the .dbf files is not available in the oradata folder, I tried to copy the files from one operation but the problem remains the same, no doubt there are a lot of missing more files.
  
  
  Appreciate your help on this.
  
  Thank you
  
  Agus

  It's a shame I don't remember that one. The error message (and solution) was a similar here: {: identifier of the thread = 2322695}, with a real solution from here: {message identifier: = 10039007}
  (Just to keep an eye on this kind of mistake and to link the case...)

  I'm glad to hear that you solved the issue now, but I'm still a bit puzzled how this could happen. Possibly management of memory to the point 10.2 XE does not get what he expected on systems with Hyper-Threading or several used CPU sockets, maybe is the fact, it cannot apply/monitor limitations as expected. Still the error message is a bit misleading.
  It would be interesting to know if 11.2 XE gets along on this platform. Maybe you have time to give it a try someday? I would recommend to use 11.2 XE for a new installation anyway... ;)
  It is likely to work because no one reported an error like that with 11.2 XE and there are a few positions, mainly on licensing issues, which indicate 11.2 would also go on HT and dual socket machines, but it is possible that they still had something different on their machines.

  -Udo

  P.S.:
  @Fredrik: If our messages overlap on this reference... ;)
  @Agus: If you think that your problem has been resolved, please mark this thread as answered and all useful/correct answer accordingly, for other users looking for a similar question will be able to easily spot the positions in question.
  Thank you!

  Published by: Udo on 23.03.2012 09:15

• 836: failed to create the shared memory data, error 22 store segment

  Hi, I am new to timesten and databases in general, and I'm testing the database timesten to test.
  
  I am running ubuntu linux in virtualbox and have java 6 is installed. So far, I installed the timesten database and configured the sys.odbc.ini to create a new database. However, it seems that I can't connect to a database.
  
  I connect with the orattadmin of the user (which belongs to groups both timesten and ttadmin)
  
  I run the commandes./ttenv.sh and I have the classpath for ttjdbc6.jar in it.
  then I run le./ttisql.sh, and when I try to connect to mydatabase or any other database present in the sample folder I get:
  
  $. / ttisql
  
  Copyright (c) 1996-2011, Oracle. All rights reserved.
  Type? or 'aid' help, type "exit" to leave the ttIsql.
  
  
  Command > Connect "dsn = mytest_ttdb";
  836: failed to create the shared memory data, error 22 store segment
  The command failed.
  
  what I am doing wrong? What can I do?
  
  Thanks for your time

  A data store active TimesTen consists of a single shared memory segment allocated from o/s. The size of this segment is PermSize + TempSize + LogBufMB + ~ 20 MB. This allowance will not allow the o/s unless the 'package' kernel parameter has a value greater than the requested size of the segment. According to the Guide of Installation TimesTen, you set various parameters of the kernel on the appropriate values (memory shared, semaphores, etc.).

  Chris

• TimesTen does not release the shared memory even after DB destroy

  Hello
  
  After that TimesTen DB is destroyed, the shared memory allocated to the DB is not to be released by the system.
  We use TimesTen release 11.2.1.7.0 (64-bit, Linux/x86_64)
  
  We need to restart the system for shared memory usage (outdated) by clearing TimesTen.
  
  Please let me know what is the problem here.
  
  Concerning
  Pratheej

  Hi Pratheej,

  How are actually destroy you TimesTen? are you using ttDestroy? It seems that you may force a shutdown of the master demon TT? In which case the current connections will not aware the master demon went so far that they try then access TT until they can keep the memory shared memory segment.

  Take a look at ttStatus to see which links are open. Unplug them all by default that TT will come out then memory, you can use ttDestroy.

  Tim

• TimesTen shared memory internal process commication

  Hi all
  
  
  My app connects to Tiemsten store data in client/server Mode using the TCP/IP protocol.
  our 32-bit Applications running on different server where the Tiemsten server running.
  
  I have the following questions on this
  
  1 can we have shared Timesten memory internal process commication to client/server architecture?
  
  2. What are the best practices to impelment SHMIPC in client/server mode?
  
  Please help me
  
  Thank you
  -AK

  Sharing memory Inter Process Communication (SHMIPC) is only possible when the client and TimesTen server are running on the same server. When the client and server are running on different machines that only TCP/IP is possible.

  Kind regards

  Chris

• An another ORA-27101: shared memory realm does not wire. :|

  Guy before you start cursing me to 'Find the fucking form' 'google before posting.
  
  I did all of this for the last week 1. I'm just not able to find a solution to this problem
  
  What all I did was searching on the forums
  
  I checked the file listener. No trailing slash is there, I checked the SID. It has been set correctly. Home is also set correctly. TNSNAMES.ora file is correct. All values of apt. SQLNET.ora is checked. No problem with that.
  
  I erased the eventviewer (Yes one of the listed forums that eventviewer being full can also cause this error), I have enough disk space.
  
  Oracle service starts and the listener service starts without any problem. But if I try to connect I get this error.
  
  I tried to restart the services, I tried to restart the machine itself.
  
  C:\Documents and Settings\nom > set oracle_sid = qa01
  
  C:\Documents and Settings\nom > sqlplus sys/oracle as a sysdba
  
  SQL * more: release 10.2.0.3.0 - Production on Sun Aug 15 21:40:09 2010
  
  Copyright (c) 1982, 2006, Oracle. All rights reserved.
  
  Connect to an instance is idle.
  
  
  
  C:\Documents and Settings\nom > sqlplus sys/oracle as a sysdba
  
  SQL * more: release 10.2.0.3.0 - Production on Sun Aug 15 22:29:14 2010
  
  Copyright (c) 1982, 2006, Oracle. All rights reserved.
  
  Connect to an instance is idle.
  
  SQL > select file #, name from v$ datafile;
  Select file #, name from v$ datafile
  *
  ERROR on line 1:
  ORA-01034: ORACLE not available
  
  
  
  When I connect
  
  C:\Documents and Settings\nom > sqlplus system / < password > @qa01
  
  SQL * more: release 10.2.0.3.0 - Production on Sun Aug 15 21:01:49 2010
  
  Copyright (c) 1982, 2006, Oracle. All rights reserved.
  
  ERROR:
  ORA-01034: ORACLE not available
  ORA-27101: shared memory realm does not exist
  
  
  
  I tried running the command start nolog. It is said of database successfully mounted, still I'm not able to connexiona my instance. immediate stop does not work. He said TNS ADAPTER error or something.
  
  I once faced a similar problem and it was related to a DBF file being deleted and oracle was not able to find it. After the issuance of orders drop (alter drop offline database datafile 13 ;) I was able to start the database. Any help will be greatly appreciated.
  
  Thank you
  Shakur
  
  PS - I'm running a virtual machine with Windows 2003 32 bit machine

  Hello

  Looking the alerts log, it seems that this data file "INFORM_01.DBF" is not available in 'E:\ORADATA\QA01 '. Come back with goodness and hopefully you're cold backup of the database or at least the application schema export dump.

  Kind regards
  Anand

• ORA-01034: ORACLE not available ORA-27101: shared memory realm isn't exi

  Hello
  
  I have Oracle 10 g Express edition installed on windows server.
  The server restarted abruptly because of a problem
  
  The client while trying to connect to oracle server this started to get
  
  ORA-12514: TNS:listener is not currently of service requested in connect descriptor.
  
  When I tried to connect as sysdba on server it gave me error
  
  ORA-01034: ORACLE is not available and
  ORA-27101: shared memory realm does not exist
  
  I tried to restart the services.
  I tried to restart the server.
  
  I also checked that Oracle_SID is not in position of work-properties - Advanced - Environment Variables.
  
  How should I address the problem?
  
  Thank you very much

  Another thing is that the service name is XE, but when I'm doing lsnrctl services, I do not get XE.

  You are right.
  The database instance, XE, has auto-Registre itself with the listener after the departures of DB.

  Oracle service is running on your PC?
  Message earlier in this thread to discuss.

  What OS user is the owner of the tree of Oracle software?

• You can use pfile instead of spfile with automatic shared memory management

  I decided to use the pfile instead of spfile method, because you can make comments in the file pfile. This became very useful however I think that I might be giving up some things.
  
  I want to know if I can use Automatic Shared Memory Management with a pfile.
  
  Also you can make to change the pfile to the database file. Example:
  change the system {some parameter} scope =... I would like here to pfile.
  
  Is this possible. I don't want to have to keep switching back, and I don't want to lose what I put in the pfile file. I read a great article in Oracle magizine on best practices for Oracle and one of them was to not use the spfile. Now, I can't find the article.

  Dear friend
  feature managent automatic memory or dynamic SGA , can not be used when you
  use pfile as meathod initialization of the instance. To use the dynamic SGA feature you
  must use the spfile.
  As you know the current status or the size of the SGA is determined by the
  Parameter SGA_TARGET , and when you want to change the size of the SGA for instnace this setting
  must be updated dynamically without restarting the ORACLE SERVER.

  And as a pfile cannot be updated by the ORACLE SERVER, it must be changed manually.
  so you cannot use automatic memory management while you use startup pfile.

  I hope this helps...