Bug in kernel_task when using an Adaptec 2940 SCSI card under OS 10.4.x - Storage

This is a discussion on Bug in kernel_task when using an Adaptec 2940 SCSI card under OS 10.4.x - Storage ; I thought I would share an experience I had recently with an Adaptec 2940 SCSI crd in my QuickSilver 733. My current system has the PCI SCSI card, and in the SCSI chain are a Zip250 and a Microtek ScanMaker ...

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Thread: Bug in kernel_task when using an Adaptec 2940 SCSI card under OS 10.4.x

  1. Bug in kernel_task when using an Adaptec 2940 SCSI card under OS 10.4.x

    I thought I would share an experience I had recently with an Adaptec
    2940 SCSI crd in my QuickSilver 733.

    My current system has the PCI SCSI card, and in the SCSI chain are a
    Zip250 and a Microtek ScanMaker 4. There is a terminator on the
    ScanMaker 4, and the Zip250 has its termination disabled.

    I recently had to use the Zip250 on an old Powerbook 165C so I
    disconnected the SCSI chain from the QuickSilver, and hooked it up to
    the PowerBook. When I was done I never hooked the chain back up to the
    QuickSilver. (I was too lazy to shut down and reconnect, and then
    restart).

    That was about a week ago. For the past week, I've had kernel_task CPU
    utilization of about 75% on average, taking up over 1GB of virtual
    memory. I couldn't for the life of me figure out what was going on,
    until I realized everything started when I disconnected the SCSI chain.

    Once I reconnected the chain, kernel_task CPU% went back down to a
    respectable 2% on average!

    I didn't install any additional drivers for the SCSI card, only what was
    included in the 10.4.0 install DVD.

    I'm thinking that the kernel_task slows itself down when it has a dirty
    SCSI bus: one that isn't terminated. So if you have a SCSI card in your
    PCI based system, you should always terminate it even if there are no
    devices on the chain!

    Cheers.
    -Patrick

  2. Re: Bug in kernel_task when using an Adaptec 2940 SCSI card under OS 10.4.x

    In article <1hsyo78.jzj3cwnfl9jrN%patrick@NOtendim.cjb.netSPAM>,
    patrick@NOtendim.cjb.netSPAM (pmp) wrote:

    > I thought I would share an experience I had recently with an Adaptec
    > 2940 SCSI crd in my QuickSilver 733.
    >
    > My current system has the PCI SCSI card, and in the SCSI chain are a
    > Zip250 and a Microtek ScanMaker 4. There is a terminator on the
    > ScanMaker 4, and the Zip250 has its termination disabled.
    >
    > I recently had to use the Zip250 on an old Powerbook 165C so I
    > disconnected the SCSI chain from the QuickSilver, and hooked it up to
    > the PowerBook. When I was done I never hooked the chain back up to the
    > QuickSilver. (I was too lazy to shut down and reconnect, and then
    > restart).
    >
    > That was about a week ago. For the past week, I've had kernel_task CPU
    > utilization of about 75% on average, taking up over 1GB of virtual
    > memory. I couldn't for the life of me figure out what was going on,
    > until I realized everything started when I disconnected the SCSI chain.
    >
    > Once I reconnected the chain, kernel_task CPU% went back down to a
    > respectable 2% on average!
    >
    > I didn't install any additional drivers for the SCSI card, only what was
    > included in the 10.4.0 install DVD.
    >
    > I'm thinking that the kernel_task slows itself down when it has a dirty
    > SCSI bus: one that isn't terminated. So if you have a SCSI card in your
    > PCI based system, you should always terminate it even if there are no
    > devices on the chain!
    >
    > Cheers.
    > -Patrick


    Oh Mary!

    You're just figuring that out? Dealing with the art of SCSI chains is
    only the beginning. Try using a SCSI tape drive and 10.4. Retrospect
    is guaranteed to panic your system when it quits. It forced me to
    finally start replacing the ancient SCSI devices with Firewire or USB.
    Now they're all gone and I'm much happier for it. I guess 15 years is
    to much to ask for a scanner and 5 years for a tape drive.

    --
    DeeDee, don't press that button! DeeDee! NO! Dee...




  3. Re: Bug in kernel_task when using an Adaptec 2940 SCSI card under OS 10.4.x

    On 2007-02-03 12:37:55 -0600, patrick@NOtendim.cjb.netSPAM (pmp) said:

    > I thought I would share an experience I had recently with an Adaptec
    > 2940 SCSI crd in my QuickSilver 733.


    Yep - you're going to have nothing but problems with 10.4 + and Adaptec
    SCSI cards. Your best bet is to move to Firewire & USB devices.

    --
    JR


  4. Re: Bug in kernel_task when using an Adaptec 2940 SCSI card under OS 10.4.x

    On 2007-02-04 02:11:40 +0200, Jolly Roger said:

    > On 2007-02-03 12:37:55 -0600, patrick@NOtendim.cjb.netSPAM (pmp) said:
    >
    >> I thought I would share an experience I had recently with an Adaptec
    >> 2940 SCSI crd in my QuickSilver 733.

    >
    > Yep - you're going to have nothing but problems with 10.4 + and Adaptec
    > SCSI cards. Your best bet is to move to Firewire & USB devices.


    But people buy SCSI based expensive stuff just because there is a less
    chance of future incompatibility problems and due to the fact that SCSI
    architecture has not many things to do with the OS (except kernel
    support)

    I would test the Adaptec site offered drivers first:
    http://www.adaptec.com/en-US/support/mac/

    or their support. They promise support, that is why people opt for them
    instead of $50 Taiwan clones, not?

    Ilgaz


  5. Re: Bug in kernel_task when using an Adaptec 2940 SCSI card under OS 10.4.x

    On Sat, 3 Feb 2007 19:11:40 -0500, Jolly Roger wrote
    (in article <2007020318114055597-jollyroger@nullorg>):

    > On 2007-02-03 12:37:55 -0600, patrick@NOtendim.cjb.netSPAM (pmp) said:
    >
    >> I thought I would share an experience I had recently with an Adaptec
    >> 2940 SCSI crd in my QuickSilver 733.

    >
    > Yep - you're going to have nothing but problems with 10.4 + and Adaptec
    > SCSI cards. Your best bet is to move to Firewire & USB devices.
    >
    >


    Err... correct me if I'm wrong, but isn't true that Adaptec has abandoned the
    2940 for Macs and that the last driver update as released in 1999, for OS 9,
    and that the 2940 is not supported, period, under OS X? In fact, hasn't
    Adaptec bailed completely from the Mac market, as indicated at this page here
    ? Apparently
    there haven't been any updates for any Adaptec Mac product, period, since
    2002, and there never will be any more. Ever.

    With that level of support I'd say that it's a miracle that those cards have
    worked this long!

    I personally last used a 2940 with a beige G3 which was running OS X 10.2. It
    worked, but I last touched that particular machine in about 2002, or about
    when Adaptec bailed completely.

    --
    email to oshea dot j dot j at gmail dot com.


  6. Re: Bug in kernel_task when using an Adaptec 2940 SCSI card under OS 10.4.x

    On 2007-02-03 21:17:27 -0600, J.J. O'Shea said:

    > On Sat, 3 Feb 2007 19:11:40 -0500, Jolly Roger wrote
    > (in article <2007020318114055597-jollyroger@nullorg>):
    >
    >> On 2007-02-03 12:37:55 -0600, patrick@NOtendim.cjb.netSPAM (pmp) said:
    >>
    >>> I thought I would share an experience I had recently with an Adaptec
    >>> 2940 SCSI crd in my QuickSilver 733.

    >>
    >> Yep - you're going to have nothing but problems with 10.4 + and Adaptec
    >> SCSI cards. Your best bet is to move to Firewire & USB devices.

    >
    > Err... correct me if I'm wrong, but isn't true that Adaptec has abandoned the
    > 2940 for Macs and that the last driver update as released in 1999, for OS 9,
    > and that the 2940 is not supported, period, under OS X? In fact, hasn't
    > Adaptec bailed completely from the Mac market, as indicated at this page here
    > ? Apparently
    > there haven't been any updates for any Adaptec Mac product, period, since
    > 2002, and there never will be any more. Ever.
    >
    > With that level of support I'd say that it's a miracle that those cards have
    > worked this long!
    >
    > I personally last used a 2940 with a beige G3 which was running OS X 10.2. It
    > worked, but I last touched that particular machine in about 2002, or about
    > when Adaptec bailed completely.


    Yep. That is precisely why I said he will have nothing but problems,
    and his best bet is to upgrade those old SCSI devices to Firewire / USB
    devices.

    --
    JR


  7. Re: Bug in kernel_task when using an Adaptec 2940 SCSI card under OS 10.4.x

    On Sat, 3 Feb 2007 22:22:27 -0500, Jolly Roger wrote
    (in article <2007020321222765340-jollyroger@nullorg>):

    > On 2007-02-03 21:17:27 -0600, J.J. O'Shea said:
    >
    >> On Sat, 3 Feb 2007 19:11:40 -0500, Jolly Roger wrote
    >> (in article <2007020318114055597-jollyroger@nullorg>):
    >>
    >>> On 2007-02-03 12:37:55 -0600, patrick@NOtendim.cjb.netSPAM (pmp) said:
    >>>
    >>>> I thought I would share an experience I had recently with an Adaptec
    >>>> 2940 SCSI crd in my QuickSilver 733.
    >>>
    >>> Yep - you're going to have nothing but problems with 10.4 + and Adaptec
    >>> SCSI cards. Your best bet is to move to Firewire & USB devices.

    >>
    >> Err... correct me if I'm wrong, but isn't true that Adaptec has abandoned
    >> the
    >> 2940 for Macs and that the last driver update as released in 1999, for OS 9,
    >> and that the 2940 is not supported, period, under OS X? In fact, hasn't
    >> Adaptec bailed completely from the Mac market, as indicated at this page
    >> here
    >> ? Apparently
    >> there haven't been any updates for any Adaptec Mac product, period, since
    >> 2002, and there never will be any more. Ever.
    >>
    >> With that level of support I'd say that it's a miracle that those cards have
    >> worked this long!
    >>
    >> I personally last used a 2940 with a beige G3 which was running OS X 10.2.
    >> It
    >> worked, but I last touched that particular machine in about 2002, or about
    >> when Adaptec bailed completely.

    >
    > Yep. That is precisely why I said he will have nothing but problems,
    > and his best bet is to upgrade those old SCSI devices to Firewire / USB
    > devices.
    >
    >


    I thought so. That same beige G3 had a FireWire card in it as well as the
    Adaptec card. I used it to migrate from SCSI drives to FireWire drives. I
    haven't used a SCSI device since I stopped using that machine.

    --
    email to oshea dot j dot j at gmail dot com.


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