Startup from External Drive and Automatically Unmount Internal Drive

Discussion in 'Apple' started by TaliesinSoft, Dec 30, 2005.

  1. TaliesinSoft

    TaliesinSoft Guest

    My SO has a PowerBook G4, a so-called TiBook. Because the internal drive is
    insufficient to hold all of her applications and documents and such we
    configured it with the intention that it would boot off of an external
    Firewire drive that is much larger than the internal drive. The Startup Disk
    is set to the external drive. All is working well with two exceptions....

    a) Subsequent to a shut down a startup will occur on the internal drive and
    not the designated startup drive.

    b) An AppleScript initiated upon startup and which has a 60 second delay will
    not eject the internal drive, but a subsequent drag and drop on the eject
    symbol will.

    The ideal situation, that which we would like to have in effect, is that
    whenever the PowerBook is started that it always by default starts from the
    external drive and that the internal drive is ejected.

    Suggestions or solutions will be appreciated.
    TaliesinSoft, Dec 30, 2005
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  2. TaliesinSoft

    matt neuburg Guest

    That is indeed the way it is supposed to work. (I have two machines that
    work this way.) If you are setting the startup disk properly, I don't
    understand why the computer would "forget" the setting. Double-check the
    setting in the Startup pref pane.
    That part makes no sense to me, so I'm ignoring it. Why would you want
    to do that? What would it mean, anyway? m.
    matt neuburg, Dec 30, 2005
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  3. TaliesinSoft

    TaliesinSoft Guest

    [responding to my stating that subsequent to startup from an external drive I
    would like to unmount the internal drive]
    This was a precautionary measure. The internal drive on the computer in
    question is shortly to be replaced. Given that the complete environment
    because of the low capacity of the internal drive is now on an external drive
    of sufficient capacity, the unmounting of the internal drive was to prevent
    anything being placed on it. This is so that when the new internal is
    installed it will be a simple task to clone the curent external to tht
    internal. (I hope that all makes sense!)
    TaliesinSoft, Dec 30, 2005
  4. TaliesinSoft

    John Johnson Guest

    Could a failing PRAM battery cause this? Should the OP consider
    replacing it while the machine is open anyway? The older PowerBooks
    seemed to want a new one after 4 years or so, but I don't know how
    improved battery technology has affected this, if at all.


    'indiana' is a 'nolnn' and 'hoosier' is a 'solkk'. Indiana doesn't solkk.
    John Johnson, Dec 31, 2005
  5. TaliesinSoft

    TaliesinSoft Guest

    I'm hesitant to think thee is a PRAM battery problem given that the PowerBook
    was just returned from Apple's repair service where the motherboard was
    TaliesinSoft, Dec 31, 2005
  6. TaliesinSoft

    John Johnson Guest

    hmmm. Does Apple replace the PRAM battery with the motherboard? I don't
    know about these things. Still, if the PRAM battery were causing this
    preference to reset, it should be causing other preferences to reset
    (and quite possibly the date/time unless you're using a time server), so
    it's fairly easy to check.


    'indiana' is a 'nolnn' and 'hoosier' is a 'solkk'. Indiana doesn't solkk.
    John Johnson, Dec 31, 2005
  7. TaliesinSoft

    TaliesinSoft Guest


    The time remains correctly set and there doesn't seem to be any problems
    other than the inability to boot from the specified drive.

    TaliesinSoft, Dec 31, 2005
  8. TaliesinSoft

    Warren Oates Guest

    I don't know why your external drive won't boot. Are you absolutely sure
    that it's bootable? Have you tried holding down the Opt key during
    startup to see if it appears on the boot screen?

    As for automatically unmounting a drive, I'm not good at shell
    scripting, but a simple grep through df would find the /dev entry
    associated with its mount point, and then it could be unmounted with
    disktool (no man pages anymore, type it at the prompt to get its usage)
    or diskutil.

    Lord, I hate it when I talk like a geek.
    Warren Oates, Dec 31, 2005
  9. TaliesinSoft

    matt neuburg Guest

    Still, it couldn't hurt to reset PRAM. Actually what I would do is reset
    Open Firmware (this is where the startup disk setting is remembered). m.
    matt neuburg, Dec 31, 2005
  10. TaliesinSoft

    matt neuburg Guest

    But it could be the cause of the problem (i.e. why the computer is
    failing to remember correctly that the exrternal drive is the startup
    drive). So why complicate the matter? Just do what works.
    But nothing will be (unless you do so). m.
    matt neuburg, Dec 31, 2005
  11. TaliesinSoft

    TaliesinSoft Guest

    The external drive in question, a LaCie 160 GB Firewire, is indeed bootable.
    It's just that it won't boot after a shut-down but will boot after a restart.
    The attempted automated eject of the internal drive is via the following

    tell application "Finder"
    if (exists the disk "Macintosh HD") then
    eject "Macintosh HD"
    end if
    end tell

    This script works as intended if the target drive is anything but the
    internal drive. Interestingly the internal drive can be ejected by dragging
    and dropping onto the eject symbol in the dock.
    Many thanks for replying, even if you did sound a bit geekish :)
    TaliesinSoft, Dec 31, 2005
  12. TaliesinSoft

    TaliesinSoft Guest


    I'll give it a try as soon as I can and will report back if that made a

    Many thanks for the suggestion.

    TaliesinSoft, Dec 31, 2005
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