9i, W2k, and memory HELP!
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Thread: 9i, W2k, and memory HELP!

  1. #1
    Join Date
    Feb 2001
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    99

    Question 9i, W2k, and memory HELP!

    Okay you gurus,

    One of the limitations we hit in our NT environment was that NT would not allow any application to exceed 2.5gig or so of memory AND NT would only deal with 4gig or RMA. No way around, it was a known issue. So, to ensure users could get their dedicated connections, we had to trim SGA and such to ensure that Oracle never tried to exceed the limit. The advice given was to make the move to W2000, which supposedly eliminated the 4gig barrier, as well as the 2.5+ gig barrier for a single application.

    Now, up on 2000 on a new box with 4gigs of ram. Getting those pesky TNS-12500 errors. Again, Metalink shows that on W2k for 4gig, the OS grabs half the memory for itself. Each new connection causes a new thread at the os level, which takes a 1mb chuck out of the memory that ORACLE has available. The quick formula they show for determing how many active concurrent users you have is (2gig - SGA)/1mb. So, if you sga is 1.8gig, you can have 200 users with dedicated sessions. 201 causes the error.

    But, have been unable to confirm if 1) W2K will definitly deal with more than 4gigs and 2) if I put 8gigs of ram in, will OS grab 4gig fo that for itself and 3) will it let oracle grab more than the old barrier of 2.5+ or so gig.

    Anyone out there using a >4gig ram config on w2k? I am thinking I can just add ram to the box and this issue will go away. ALso thinking that MTS might be the way to go, since I need to support about 400-500 users beating at the door at any given time..

    Thanks
    Bob

  2. #2
    Join Date
    Oct 2000
    Location
    Germany
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    1,185
    I work on Solaris, so i canīt address Windows issues.

    As far as MTS goes, it is not a cure all. It works well if transactions are short. Reports or long running query can tie up your resources and prevent all but a few users from getting any resources.
    David Knight
    OCP DBA 8i, 9i, 10g

  3. #3
    Join Date
    Feb 2001
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    99
    Thanks David, thats good to know. I have never worked with MTS so not very familiar with its limitations...

  4. #4
    Join Date
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    Chicago IL
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    W2k is a good os but if you want better performance goto unix - if affordable. You can throw more memory to NT and it will chew it up. I am not sure about the limits but I don believe you will get stuck at 2.5Gb
    "High Salaries = Happiness = Project Success."

  5. #5
    Join Date
    Feb 2001
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    unfortunately, Unix is not an option. The metro government I am working in is firmly entrenched in Windows. Workstations, servers, mail, etc....we are a Windows Enterprise.

    So, may have to really try the "throw more ram at it" and see if it cures the ills.

    Thanks

  6. #6
    Join Date
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    Location
    Chicago IL
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    Maybe you should think about load balancing with OPS if you can have 2 servers. This will help you with performance - I have done this type of implimentation. You will have problems with connections but there are some things you can do like:

    1. disconnect users who are not active after 25 minutes no no activity etc..

    2. ensure all bad connections are cleaned up via sqlnet.expire_time

    etc etc
    "High Salaries = Happiness = Project Success."

  7. #7
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    Oracle Certified Master - September, 2003, the Second OCM in China
    *** LOOKING for PART TIME JOB***
    Data Warehouse & Business Intelligence Expert
    MCSE, CCNA, SCJP, SCSA from 1998

  8. #8
    Join Date
    Feb 2001
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    99
    Thanks. That answers alot of the questions. Still have to work on some others.

    Is anyone using VLM on a database with W2000?

  9. #9
    Join Date
    Apr 2002
    Location
    Phoenix, AZ
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    Sridhar R Patnam

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