Re: Sizing JFSLog

From: Bill Verzal (BVerzal_at_KOMATSUNA.COM)
Date: 06/26/03

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    Date:         Thu, 26 Jun 2003 12:41:41 -0500
To: aix-l@Princeton.EDU

    I would say that a question like this is very much like "How much swap
    space is needed?"

    If your filesystems are fairly static, then a single JFSlog will suffice.
    If you have high amounts of I/O to filesystems, then more may be in order.
    The system error log will tell you if there are JFSlog shortcomings.

    I've run DB2 backups to 136 concurrent 2GB mount points with a single
    JFSlog and never had any JFSlog problems.

    BV
    --------------------------------------------------------

    Bill Verzal
    AIX Administrator, Komatsu America
    (847) 970-3726 - direct
    (847) 970-4184 - fax

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    I am in an AIX performance tunning class as of this writing.
    We were told 4 mb for each 2 gig of file system space.

    -----Original Message-----
    From: "IBM AIX Discussion List" <aix-l@Princeton.EDU> on behalf of
    "Theresa Sarver" <tsarver.IFMC@SDPS.ORG>
    Sent: Thu, 26 Jun 2003 12:22:12 -0400
    To: "aix-l@Princeton.EDU" <aix-l@Princeton.EDU>
    Subject: Sizing JFSLog

    Hi All;

    What is the proper size of the JFSLog on an AIX system (either 433 or 5L)?

    I have always set it at the default of 1PP. However, I have a colleague
    that is saying that "IBM recommends a 2 MB log size per 1 GB of file system
    space."

    I can't find any documentation stating that either one is correct...does
    anyone know where I might find some?

    Thank you!
    Theresa

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