Query on sd_max_throttle

From: Padmaja Nambiar (padmajac_at_india.hp.com)
Date: 06/28/05

  • Next message: Gundlapalli, Kodandapani (Kodandapani)** CTR **: "C compiler not working"
    To: <sunmanagers@sunmanagers.org>
    Date: Tue, 28 Jun 2005 11:05:07 +0530
    
    

    Hello everybody,

    I had a question on the significance of the parameter "sd_max_throttle"
    on a Solaris host.

    The definition that I get for this parameter is that it the maximum number
    of commands that the SCSI sd driver will attempt to queue to the HBA driver
    (default 256). This variable should be set to a value less than or equal to
    the maximum queue depth of each LUN connected to each instance of the sd
    driver.

    In the above definition, what does "maximum queue depth of each LUN
    connected to each instance of the sd driver" mean. Is this the same as
    "sd_max_throttle", or does it get set as some other variable?

    On my solaris host, sd_max_throttle is set to 32, and the queue depth for
    the qla2300 driver is set to 16. Could somebody please explain how things
    will work in this scenario? Does it make sense to have a value of 32 for
    sd_max_throttle when the execution throttle for the Qlogic driver is set to
    only 16?

    Thanks in advance,
    ~padmaja.
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