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Re: Oracle on Windows 2000 AS with /3GB flag

From: kathy duret <>
Date: Wed, 18 Jul 2007 07:02:27 -0700 (PDT)
Message-ID: <>

when we upgraded our boxes we had dual core 4 cpus but the new box was also hyperthreaded. These were Dell boxes.and windows 2003 32 bit. Oracle    

  Many of the hidden parameters changed values as well as others (saw 16 cpus instead of 4, and others) I actually got 100 less sessions with the new cpus until I turned off ASMM and put in a smaller sga max and target values. I also decreased my large pool size, java pool (your mileage may vary, I COULD reduce these you may NOT be able to).    

  I don't like to go into too many specifics because depending upon what machine, what operations system, what patch set, what oracle version you are on and what parameters you have set in you system - your mileage may vary and some people take values as gospel instead of testing what REALLY works for there system.    

  Orastack is a great tool to decrease the size of all your sessions but you need to test carefully to make sure you don't decrease the size too much or you will start recieving some ora-03113 errors. You need to shutdown the database to reset. I set my a bit larger than I the limit. The lowest setting is 512000 not 500000.    

  Orakill is a nice tool as well. If I kill some of my Business Object sessions or some of our home grown VB app, it does kill the session but it stays taking up memory and taking up a thread until the session is bounced.    

  Also if you have these old killed sessions around the spid is gone and you can't used orakill anymore. Also double check your number before you execute this so you don't kill the wrong session!    

  orakill dbname spid    

  This is the query I use to identify inactive sessions   select spid, module, osuser, logon_time, sid, s.serial#, (SYSDATE - last_call_et / 86400), s.program   from v$database d, v$session s, v$process p   where s.paddr = p.addr and status = 'INACTIVE'   --and module = 'jobserverchild.exe'
  and logon_time <= sysdate - 2
  and (SYSDATE - last_call_et / 86400) <= sysdate - 2   order by s.program, logon_time    

  Again test and see if this works for you. I will be updating my article to include this new orakill information.    

  I have about 20 more months to go on this system and when time permits I keep investigating new things to keep this thing going.    

  If anyone else has come across s    

  If you have some new ideas I will be happy to investigate and add thiings to my article.        


Richard Saints <> wrote:   

Hi Kathy,
thanks for your feedback.

What do you mean by "Watch out for hyperthreading on cpus" ? The test system that failed to start the database has 2 CPUs on hyperthreading mode.

I was planning to activate /3GB because I want to increase the value allocated to the SGA (currently 1336MB). And I would like to continue to use ASMM (Automatic Shared Memory Management).

I started to read your metalink article and I had a feeling of "deja-vu".

I also would like to thank everyone of the list who gave me some feedback.

Best Regards,

  On 7/17/07, kathy duret <> wrote: Check Metalink. You will find all sorts of docs on /3G   I am surprised to hear it didn't work on the test system.    

  Watch out for hyperthreading on cpus. This affects alot of hidden parameters.   I had to take off the auto sga and decrease my sga target quite a bit.    

  No not applicable on 64 bit Windows.    

  I did have issues with /PAE switch and performance.    

  I am working with Orakill now to kill session vs using alter session kill.   I found on windows killing sessions didn't always work and orakill does.   I will add my orakill info to my article next week hopefully.    


Richard Saints < > wrote:        

  Hello to you all,
  I'm planning to activate the /3GB flag on a Windows server running Oracle Database, in order to extend the memory that can be used by Oracle.   The server has the following characteristics:   HP Proliant DL380
  2 x Pentium Xeon 3,2 GHz
  4 GB of RAM
  HP Smart Array SCSI controller
  2x36GB SCSI RAID 1 internal discs with 2 logical drives:   C drive for OS
  D drive for Logs
  4x146 GB SCSI RAID 5 internal discs with 1 logical drive:   F drive for data
  Paging size on C drive (2048-4096)
  SO: Windows 2000 Advanced Server SP4
  The Oracle SGA Target is 1336 MB    

  I would like to know if there is any special care that I should take, before I activate this flag on boot.ini.   I read the Oracle Documentation, but I didn't found any particular aspect.    

  I'm asking this because I had a bad experience with a test server where with the /3G flag was activated and the Oracle instance didn't startup. I still haven't figured out why.        

  Thanks for all your attention.    

  Best Regards,

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Received on Wed Jul 18 2007 - 09:02:27 CDT

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