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  • 1.  Rollback to default system ioo and vmo parameters

    Posted Fri August 17, 2007 10:58 AM

    Originally posted by: SystemAdmin


    OS: AIX 5.3 L on p550 (~4G mem) with Oracle 10g R2 and Baan 5c.
    I implemented the ioo and vmo changes a month ago (following many papers recommended to Oracle 10g), for some reasons, those new parameters do not imporve the performance of the Baan 5c and Oracle; actually worsen some processes. So how do I rollback all the parameter to default. Here is the list of the parameters (of current)
    1. vmo -r -o lgpg_regions=84 -o lgpg_size=16777216
    2. vmo -p -o minperm%=5
    3. vmo -p -o maxperm%=90
    4. vmo -p -o maxclient%=90
    5. vmo -p -o lru_file_repage=0
    6. ioo -p -o maxpgahead=128
    7. ioo -p -o j2_maxRandomWrite=16
    8. ioo -p -o maxrandwrt=32
    9. ioo -p -o j2_nBufferPerPagerDevice=1024
    10. ioo -p -o pv_min_pbuf=1024
    11. ioo -p -o numfsbufs=2048
    12. chdev l sys0 a maxuproc=512
    13. chdev -l aio0 -P -a maxservers=300
    Although I have the list of old values, I am not sure they are valid. Is a way I can rollback them to defaults?


  • 2.  Re: Rollback to default system ioo and vmo parameters

    Posted Fri August 17, 2007 12:16 PM

    Originally posted by: SystemAdmin


    I found out them in AIX lib
    ioo -p -D
    vmo -p -D
    But have not found the default of maxuproc and maxserver.


  • 3.  Re: Rollback to default system ioo and vmo parameters

    Posted Fri August 17, 2007 12:21 PM

    Originally posted by: SystemAdmin


    lsattr -Dl <device> for the default values


  • 4.  Re: Rollback to default system ioo and vmo parameters

    Posted Fri August 17, 2007 02:01 PM

    Originally posted by: VirtualGreg


    Your vmo settings are in-line with best practices and I don't see how they could create any negative impact. I'd always recommend at least you vmo settings for an Oracle server and also set AIXTHEAD_SCOPE=S in /etc/environment.

    Lowering maxuproc is potentially asking for failures to occur when new processes can't be created to service requests. Leave it alone. Even if you over configured AIO I'm sure you'll do no harm.

    You are probably going to be far better off looking at the database with an Oracle tuning expert.


  • 5.  Re: Rollback to default system ioo and vmo parameters

    Posted Fri August 17, 2007 05:03 PM

    Originally posted by: SystemAdmin


    There are three parts in current system, OS, Oracle and Baan. I am taking care of the OS and Oracle. I have no knowledge of Baan and since its job is contracted, I can not touch on that part. So I have set up every best configurations for OS and Oracle accordingly.

    Our env does has AIXTHEAD_SCOPE=S

    By Oracle diagnosis, there are many Network idle messages pointing to the Baan (client) from/to Oracle (server). So Yes, I do suspect that the serious problems occur at that level.

    Does AIX provide any tool to examine the network activity, either from external client ( a user desk PC) or internal client (as Baan to Oracle) on the same box but different devices (HD)?

    Thanks for your inputs.


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