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  • 1.  CPU is 100 used by user processes (db2), but memory and hdisk are not busy

    Posted Sun March 28, 2010 11:56 PM

    Originally posted by: apple08


    Dear AIX gurus,
    would like to seek your advice. we had relocation, and after that one of the lpar the cpu is consistently 99-100% utilised and it has 177 idle process. How to know the idle process proportion to cpu utilisation? how to know if the cpu is healthy or otherwise? when i compare the utilisation before and after relocation, the utilisation is 5 times. would appreciate can shed some lights. Hope to hear from you. Many thanks in advance.


  • 2.  Re: CPU is 100 used by user processes (db2), but memory and hdisk are not busy

    Posted Wed March 31, 2010 06:34 AM

    Originally posted by: nagger


    Hi,
    You should investigate the busy running processes and not the idle ones.
    Lots of idle processes is fairly normal on large database systems.

    How are you measuring utilisation?

    I would use topas and then hit P for processes to find out the busy ones or use nmon if you have it.

    Perhaps, after the relocation (normally called Partition Mobility unless you are using Application Mobility which is called Relocation on the WPAR Manager - we really need to get these names sorted out), you have a spinning process or two that is causing the 100% utilisation.

    What size is the LPAR Entitlement, is it capped? If not capped it can get to 100% as it gets to use the Entitlement and can then go a lot faster so 100% can be normal.

    Anyway, lots more information is needed to help you, ta Nigel


  • 3.  Re: CPU is 100 used by user processes (db2), but memory and hdisk are not busy

    Posted Wed March 31, 2010 10:13 AM

    Originally posted by: apple08


    Dear Mr Nigel,
    archival db2 logs keep generating in every 1 minute which is not normal. that possibly cause the server to be very busy. we have another set of server at recovery centre and we have swing the application to recovery centre. strangely, the server at HQ is busier compared to the server that running production application at RC.
    the server are running db2 replication and during that time the destination server is busier that the target server. till today we don't know the cause. we have engaged IBM DB2 to help us out. the server is running HACMP. we physically relocated the server from old data centre to new data centre. Should u require any information or logs, would appreciate your notification Sir. Many many thanks. Thank you


  • 4.  Re: CPU is 100 used by user processes (db2), but memory and hdisk are not busy

    Posted Wed March 31, 2010 10:22 AM

    Originally posted by: apple08


    Dear Mr Nigel,
    yes, we are using nmon extensively/enterprisely. Any comments, feedback, would really appreciate. Many thanks


  • 5.  Re: CPU is 100 used by user processes (db2), but memory and hdisk are not busy

    Posted Mon April 05, 2010 07:17 AM

    Originally posted by: apple08


    Dear Mr Nigel,
    would like to seek your advice. we have performed DB2 reindex, so far the CPU was not high, but our previous problem appear. The SAN hdisks are very busy. If we tune this parameter, mbuf_heap_psize and kernel_psize, will it help? why we need to increase this value? Hope to hear from you. Many thanks in advance


  • 6.  Re: CPU is 100 used by user processes (db2), but memory and hdisk are not busy

    Posted Fri April 23, 2010 06:34 PM

    Originally posted by: Pave1


    Hi,

    just a stupid question, have both lpars same CPU cfg? Mean entitled CPU.
    What tool shows you 100% utilization?
    Is most of CPU spend in sys or in user time?
    There is really too low details to be able to help you ...

    Cheers,
    Pavel


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