Unable to correctly set startup disk

Discussion in 'Mac Pro' started by pstadelmann, Oct 12, 2015.

  1. pstadelmann, Oct 12, 2015
    Last edited: Oct 12, 2015

    pstadelmann macrumors newbie

    Aug 18, 2015

    Today I installed an AccelsiorM PCIe card with a Samsung EVO mSATA SSD in my Mac Pro 3.1.

    I then booted the computer using my current boot drive (OS X 10.10.5) and since I saw that the SSD was recognised, I proceeded to install El Capitan on it. In the middle on installation, the Mac rebooted, but instead of booting El Capitan, it booted from a 10.6.8 partition ! I rebooted the computer and selected the SSD at boot time (using the option key) and installation of El Capitan completed without issue.

    Now, when I reboot the computer and hold the option key, I can choose whatever OS (10.6.8 or 10.10.5 from SATA hard disks, or 10.11 from the SSD), it boots and works correctly, and all other OS partitions are mounted and usable. But whatever the selection in the Startup disk preferences, the computer always boot 10.6.8 by default !

    In 10.6.8 I only see the 10.6.8 disk in the Startup disk preferences. If I use systemsetup setstartupdisk to set another disk, I get errors that /Volumes/THEDISK/System/Library/CoreServices is not a valid system (where THEDISK is either the 10.10.5 or 10.11 partition)

    From 10.11 and 10.10.5 I see all bootable partitions in the Startup disk preferences, if I choose e.g. 10.10.5 while booted in 10.11, the computer will correctly boot 10.10.5.

    But if I choose 10.11 from either 10.11 or 10.0.5, the computer reboots in 10.6.8. If I then reboot and use the option key to boot 10.11 and open the Startup disk preferences, it tells me that 10.11 is the selected boot disk.

    In 10.6.8 I see that no boot disk is selected in Startup disk preferences (nothing is written to the left of the Restart button). If I use systemsetup getstartupdisk the answer is /Volumes/SSD/WINNT (!!!) SSD is indeed the name of my 10.11 partition, but I have no idea where WINNT comes from !!! Of course this directory does not exists. The expected answer would be /Volumes/SSD/System/Library/CoreServices

    I’ve reset the PRAM but that didn’t change anything.

    Any idea what’s going on and how to fix it ?

    Thanks a lot for any help !

    EDIT: I forgot to mention that the SSD disk is seen as removable by the OS, though I'm not sure if this is relevant.
  2. mbosse macrumors regular

    Apr 29, 2015
    Vienna, Austria
    I have a similar situation: My cMP has an original Apple Toshiba SATA SSD (empty) as well as a FD composed of an Apple PCIe SSD mounted with an adaptor and a standard internal HDD. The FD has an installation with 10.11.

    Of course, the FD is seen as an external drive.

    As I had a 10.11 installation originally on my Apple SATA SSD, also the Recovery partition is still residing there.

    Every time I tried to start up the machine it boots by default into the Recovery partition. Also like in your case I can select the FD as boot drive, but the system seems to forget this after being powered down - and again starts into the Recovery partition.

    I came to the conclusion that Mac OS prefers to boot from an internal drive even if that is only a Recovery partition.

    I would love to hear thoughts from experienced users, e.g. MacVidCards.

  3. haralds macrumors 6502a


    Jan 3, 2014
    Silicon Valley, CA
    El Capitan uses CoreStorage, which is not recognized by Lion.
    You need to boot into El Capitan with the option key depressed and then set the startup.
    All drives connected to PCiE SATA controllers are seen as external. That should not change their boot behavior.
    On one of my systems, I have had trouble setting default boot to a PCiE connected drive. You can option boot and select it in Startup Drive. But it will always default to a a drive mounted on one of the factory drive controllers. No answer for that one - yet.
  4. mbosse macrumors regular

    Apr 29, 2015
    Vienna, Austria
    Thank you - anybody else ready to share some insights? Or is an answers already found in another thread? Thanks!
  5. pixelrogue macrumors newbie

    Jun 8, 2012
    While a year later, thought this might be worth a reboot.

    Similar Issue
    Mac w/an external drive connected. When machine reboots, by default it startup from an external partition which has a backup iOS partition. At the moment the internal drive is running 10.11.6, while the external is still running 10.10.5. Forces me to either disconnect the external drive or manually select.

    How can the default startup drive be changed to pick the INTERNAL drive? Isn't the internal always meant to be the default?
  6. scribling macrumors newbie


    Apr 24, 2017
    Did you ever get this resolved? I'm having the same WINNT issue. I have no idea where the WINNT is coming from or why but it's preventing my bootup.

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