rodion15

Q: Monolithic OS X, myth or reality? Should an OS X from a mac work in a different mac?

I've been told this by a colleague and I'd like to know if this is or isn't correct:

 

If you use take the hard drive from a macbook and install it in an iMac, then the iMac may not have the appropriate drivers, so you would need to do an OS X update to make sure its drivers are updated. Even if the OS X is the same or newer that the OS X that originally came with the machines.

 

He also mentioned Monolithic OS X, which means that, an OS X boot volume for a specific Mac may not have the necessary drivers (or Kernel Extensions, to use Apple terms) that another mac would need, which means it shouldn't always work correctly in another different mac.

All this provided both macs are able to run that OS X version (example: a 2011 macbook air and a 2013 iMac) and that the OS X release and update are the same or newer to the one they were released with.

 

I thought this was true for Windows PCs, but not for OS X, in OS X, my assumption is that, even if you install OS X without internet connection using an installer, that OS X will contain all the kernel extensions and should run whatever mac you install it to, provided it's a compatible mac. All provided the OS X version and build is the same or newer to the OS X version that originally was installed in the macs.

There's "system builds" specific for certain macs, but even so, if you installed a bootable hdd from another mac in this one, it should work fine provided the OS X is that specific build or a later newer OS X.

Posted on Jun 22, 2016 10:05 AM

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Q: Monolithic OS X, myth or reality? Should an OS X from a mac work in a different mac?

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  • by Kurt Lang,Solvedanswer

    Kurt Lang Kurt Lang Jun 22, 2016 10:56 AM in response to rodion15
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    Jun 22, 2016 10:56 AM in response to rodion15

    Yes, it's the same for Macs as Windows. The main difference being the Mac OS is (mostly) transparent about hardware drivers. Windows makes it obvious it's installing dozens of device specific drivers.

     

    When all Macs came with installer disks, those gray disks were machine specific, the same as machine specific disks that shipped with a Dell, Sony, Acer, or other PC. If as an example you were talking about Win 7, the build that came with the computer only had the drivers for that PC on it. For a retail Win 7 disk, it contains the info it needs to install in a way that's basically functional on a lot of different PCs, and when it has an Internet connection established, searches Microsoft's servers for the thousands of hardware drivers provided by the vendors who make them, if they aren't already on the disk, so the correct hardware drivers can be installed.

     

    When Apple switched to downloadable OS's only (starting with Lion, 10.7.x), the firmware of those Macs retrieved the machine specific build of OS X from Apple's servers. Same idea as the gray disks, except over the Internet. You couldn't use the version of Lion available to everyone else via the App Store because that was meant for older Macs Apple provided driver support for. It was very unlikely to have the drivers for your latest release Mac that shipped with Lion. Bring this forward to each newer Mac and its provided OS.

     

    Apple has always only supported a newer OS on older Macs, but not an older OS on newer Macs. Unlike MS, who provide drivers for all kinds of older hardware so you can run Win 7 on a PC made three years ago, Apple doesn't do that. The older versions of the Mac OS are never updated to include drivers for newer models.

     

    Lastly, Apple used to leave it up to the user to learn what Macs are supported on what Macs. This led to many users loading OS X from gray disks not meant for different hardware. Then those users would complain about how badly their Macs ran. No surprise since the correct hardware drivers didn't exist. Later, Apple changed the installers to detect the hardware you were trying to install OS X on. If the drivers for that Mac didn't exist in the installer, it would refuse to install.

  • by rodion15,

    rodion15 rodion15 Jun 22, 2016 12:29 PM in response to Kurt Lang
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    Jun 22, 2016 12:29 PM in response to Kurt Lang

    Thanks for your answer, quite good!. Then I guess if you fit in an OS X hdd into several macs and run an update on each, you'll have an os X that will work in all these macs, right?. This should be a way to create a universal OS X for macs (provided the macs admit that os x).  Am I right?

  • by Kurt Lang,

    Kurt Lang Kurt Lang Jun 22, 2016 12:48 PM in response to rodion15
    Level 8 (37,696 points)
    Jun 22, 2016 12:48 PM in response to rodion15
    Then I guess if you fit in an OS X hdd into several macs and run an update on each, you'll have an os X that will work in all these macs, right?.

    Sorry, no. If you clone an OS that isn't meant for a different model, it may boot, but will run badly. If it's an older OS than that model shipped with, it won't boot at all. That, and no amount of updating will install the drivers that it should have. That only happens during the initial, full install. Also, that "older" OS doesn't even need to be that much older. My 2011 Mac Pro (mid 2010 model) shipped with 10.6.4. It will not boot to the 10.6.3 retail disk.

    This should be a way to create a universal OS X for macs (provided the macs admit that os x).  Am I right?

    Only if they're all the exact same model and so already share the same drivers.

  • by rodion15,

    rodion15 rodion15 Jun 22, 2016 9:54 PM in response to Kurt Lang
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    Jun 22, 2016 9:54 PM in response to Kurt Lang

    At the workshop I work we have a hard drive with Yosemite that will boot any mac that admits Yosemite.  We use it for testing all macs.  A workmate told me that the tech who did it made it to be universal, I don't know how.  Do you know how I may create such Universal OS X? I'd like to do it with El capitan.

    Thanks again for your answers.

  • by John Lockwood,

    John Lockwood John Lockwood Jun 23, 2016 2:56 AM in response to rodion15
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    Jun 23, 2016 2:56 AM in response to rodion15

    When you buy a new Mac it will of course have the latest operating system pre-installed however depending on when that Mac model was launched and when you buy it there is a good chance it will be a version of the operating system that will only work on that specific model of Mac.

     

    When Apple issue a new updated version of the operating system e.g. El Capitan 10.11.5 it will include all the drivers for all the models of Mac released up to that point that are capable of running El Capitan. If you install this freshly downloaded from the App Store version of e.g. El Capitan it will then install a version that can be booted on all those supported Macs.

     

    1. A new Mac requiring OS X 10.11.3 is launched, it will come with a customised version of 10.11.3 for that specific new model.
    2. Later Apple release OS X 10.11.4, if you download this from the App Store it will be able to install and boot all Macs including the above Mac in point 1.

     

    Just to make it clear the version of OS X installer you download from the Mac App Store is a universal one that supports all models released prior to that version.

     

    The Combo Updater should be able to update a version of OS X similarly. So the following would apply.

     

    1. A new Mac requiring OS X 10.11.3 is launched, it will come with a customised version of 10.11.3 for that specific new model.
    2. Later Apple release OS X 10.11.4, if you install the combo 10.11.4 update then it should be able to boot all Macs including the above Mac in point 1.

     

    Note: As Macs no longer come with install media e.g. a DVD the fact that original DVD copes were indeed specific to particular models no longer is relevant.

  • by Kurt Lang,

    Kurt Lang Kurt Lang Jun 23, 2016 6:58 AM in response to John Lockwood
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    Jun 23, 2016 6:58 AM in response to John Lockwood

    Good to know. Is that a more recent change? Many users have noted in the past you can't do that with the general release. Like having an iMac that came with the machine specific version of 10.8.2, but would still refuse to allow you to install the 10.8.5 App Store version.

  • by John Lockwood,

    John Lockwood John Lockwood Jun 23, 2016 7:09 AM in response to Kurt Lang
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    Jun 23, 2016 7:09 AM in response to Kurt Lang

    Kurt Lang wrote:

     

    Good to know. Is that a more recent change? Many users have noted in the past you can't do that with the general release. Like having an iMac that came with the machine specific version of 10.8.2, but would still refuse to allow you to install the 10.8.5 App Store version.

     

    As far as I am concerned they were/are wrong. As long as the App Store version is newer your safe, if is the same version you will probably have a problem, if the App Store version is superficially the same then you probably will have a problem.

     

    10.8.5 is not the actual full version there is also a build number, the build number is what indicates if it is really the same or not, if a Mac comes with say 10.8.5 build 10A33 then an App Store version of 10.8.5 build 10A12 would not work since it is slightly older even though the headline version number of 10.8.5 is the same.

  • by Király,

    Király Király Jun 23, 2016 7:26 AM in response to rodion15
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    Jun 23, 2016 7:26 AM in response to rodion15
  • by John Lockwood,

    John Lockwood John Lockwood Jun 23, 2016 7:34 AM in response to Király
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    Jun 23, 2016 7:34 AM in response to Király

    Király wrote:

     

    Apple's official word: Use the version of OS X that came with your Mac, or a compatible newer version - Apple Support

     

    Absolutely. A newer version from the App Store is a newer compatible version.

     

    As the above Apple article says "make sure the version and build of OS X installed on the external drive is the same as, or newer than, what came with your Mac".

  • by Kurt Lang,

    Kurt Lang Kurt Lang Jun 23, 2016 11:14 AM in response to John Lockwood
    Level 8 (37,696 points)
    Jun 23, 2016 11:14 AM in response to John Lockwood

    So for the most part, it's the same as Macs have always been. Same or newer compatible version of the Mac OS can be used. Older versions cannot. Odd that a couple of Mac centric magazines I read didn't clarify the App Store versions this way. They both stated if you're going to install the same first point release the Mac came with (such as 10.9.x), you have to do it from Internet Recovery Mode, and not from an App Store version of 10.9.x. Meaning, they said 10.9.3 wouldn't work on a Mac that shipped with 10.9.0. From yours and Király's notes, this is wrong.

     

    So really, it's this:

     

    1. Any OS older than what a Mac shipped with cannot be installed, with very small exceptions. Like our Mac Mini that by its serial number, shipped with 10.6.4 and per Apple's own tech support, should not be able to install the 10.6.3 retail disk on. But I did, and it runs fine.

     

    2. Gray disks. Machine specific and cannot be used with other Macs for the obvious reason. The drivers can't ever be updated on a pressed disk, so it will always only be usable for the Mac it's meant for.

     

    3. App Store versions of OS X. Will install on all supported Macs that shipped with the same, or older build number.

     

    4. If you're selling the Mac, then you have to wipe the drive and reinstall via Internet Recovery Mode. If you were to use the App Store version of (example) 10.8.4 on a Mac that shipped with 10.8.1, it would be tied to the Apple ID of the person who installed 10.8.4 and the new owner would not be able to reinstall the OS without first wiping the drive.

     

    Please note anything you see that still needs to be corrected.

  • by rodion15,Helpful

    rodion15 rodion15 Jun 25, 2016 1:35 AM in response to John Lockwood
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    Jun 25, 2016 1:35 AM in response to John Lockwood

    Sorry, what you're saying is very interesting and is being contradicted by some experienced apple technicians here.  I'd like to make sure I understand you.

     

    You mean 1 is right and 2 is wrong?:

     

    1. A bootable OS X that you have installed in a hard drive, should boot any mac that admits that OS X, provided the OS X version and build is the same or newer than the one the mac originally had.

     

    2. An OS X installer, should install and work fine in any mac that admits that OS X, provided the OS X version is the same or newer than the one the mac originally had.  But it may not boot and work properly with another mac model, even if that mac admits that OS X version, because during the installation the appropriate drivers (kernel extensions) for that mac are installed.  (this is what my colleagues say).

     

    3. If you install an older version instead (example: you install 10.10.2 instead of the 10.10.3 that came with the machine, and you're so lucky that it starts), and then install a 10.10.4 combo update, your machine should work fine.

     

    If this is true: I may say: if you install the last version of OS X from the app store in an external hard drive, it should boot any existing mac, with the only provision that the mac isn't so old as not to admit that OS X version.

     

    Many thanks

  • by John Lockwood,Helpful

    John Lockwood John Lockwood Jun 25, 2016 1:35 AM in response to rodion15
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    Jun 25, 2016 1:35 AM in response to rodion15

    My experience is that if you use a new enough OS X installer it will work for all current/previous Macs, and yes also that the resulting drive will boot all relevant Macs.

     

    This is a very common approach by System Administrator to build an external portable drive to carry around with them to use to boot and repair all models of Macs. We do this all the time and then run DiskWarrior etc. from that drive.

  • by rodion15,

    rodion15 rodion15 Jun 25, 2016 1:27 AM in response to John Lockwood
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    Jun 25, 2016 1:27 AM in response to John Lockwood

    Hi John, I'm ACMT working for an Apple service provider.  That's what all techs do here, we have an external hard drive with bootable volumes of OS X 10.11, 10.10, 10,9, etc and use them to boot any mac from them for diagnosing.  However,  we are supposed to use them only for a quick check, disk warrior, etc.  I personally never had an issue, but in theory is seems that you may have issues because such drive (usually called a monolithic OS X, since it's intended for a specific Mac only) may not have all of the appropriate kernel extensions for the mac you're testing.  That is my doubt actually: is this a myth? or something that was so in the past?.  By what I've been said, we should test our machines by booting them from a Diagnostics NetBoot image on our image server.

    This diagnostic image is modular and will identify the Mac by its model number and then load the correct drivers on boot.

    The Image can’t be edited either so it won’t get corrupted with use. We should be using this for troubleshooting on the Macs because it’s running the correct drivers for software issues.

    If this is true, using a bootable OS X for any mac may produce problems such as fans spinning out of control, sensor issues, or whatever other driver incompatibility issues.

    Thanks for your answer

  • by John Lockwood,

    John Lockwood John Lockwood Jun 25, 2016 1:39 AM in response to rodion15
    Level 6 (9,240 points)
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    Jun 25, 2016 1:39 AM in response to rodion15

    If the monolithic image did not have all the required kernel extensions it would not boot successfully on all models of Macs and it would not allow using the hardware features of all those Macs. This approach is also how a NetBoot image works as used by for example DeployStudio to boot in to before running the workflow to restore an image. There is nothing that prevents having all drivers i.e. kexts installed, the operating system loads those it needs. Remember some kexts are for hardware that can be unplugged, this does not suddenly make it unbootable.

     

    The only issue I have seen with a universal boot drive is that the network interfaces will not have the right names on some models. This is because En0 will be WiFi on some models and En0 will be a wired Ethernet port on others.

     

    I think you are misunderstanding the diagnostic NetBoot image. It is booting a universal stripped down and customised OS image, and then based on the model it detects it has booted on runs a model specific diagnostic app. This is what Apple use in the Apple Stores.

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