Set partition bootable mac os x

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What makes a volume bootable? This article is for an older version of CCC. You can find the latest version here. Printer-Friendly Version Product:. Bootability comes down to a few simple rules: The hard drive enclosure must support booting a Macintosh applies to external hard drives only.

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The computer must support booting from the interface used to attach the hard drive e. USB, Firewire, Thunderbolt.

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The computer must support booting from the hard drive's partition format e. The cloned filesystem must have all the required components of macOS. The cloned operating system must be properly "blessed". When that test succeeds, you hear the characteristic Macintosh startup chime. The computer's pre-boot firmware software that is embedded in a chip on the computer's motherboard takes account of the hardware that is present, builds a device tree, and determines which hardware device to boot from more on this in a bit.

For the sake of simplicity, let's suppose a machine is configured to boot from particular volume on a particular hard drive. The firmware of the computer accesses the filesystem of that volume and determines the location of the file, or folder containing the file, that is "blessed" to initiate the operating system. That file is executed by the firmware and control of the hardware is handed over from firmware to the booter.

How to create a bootable macOS installer drive

The booter executes the kernel of the operating system and pre-loads a kernel extensions cache or in later OSes, the booter loads a pre-linked kernel cache file. The kernel initiates the rest of the boot process primarily by executing launchd. I haven't tested this, but if you use dd to copy the entire raw volume, that should copy the boot blocks along with the filesystem contents, so nothing else should be necessary to make the volume bootable. But I wouldn't recommend dd , as it can't cope with minor details like the source and destination volumes not being exactly the same size.

It's also painfully slow unless you use the raw device entries i.

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Instead, I'd recommend the asr tool for copying the volume; it's smarter, and more adaptable. You can also use the Restore tab in Disk Utility which actually uses asr to do the job. I'm pretty sure that asr also takes care of bootability, although it's been a while since I used it in this mode. Sign up to join this community. The best answers are voted up and rise to the top. Home Questions Tags Users Unanswered. Asked 6 years ago.

Make Bootable USB flash drive for Tiger, Leopard, Lion, Mountain Lion, Mavericks OS X

Active 6 years ago. Viewed 4k times. This only applies to computers running When a disc is formatted as what's called the Apple Partition Scheme.

This is how PowerPC machines read information. Intel machines can also read Apple Partition Scheme drives.


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This only applies to making a bootable volume btw. For example, I have 2 external HDDs. This disc's partitions are Apple Partition Schemed. Now this is important. So when you format the drive in Disk Utiliy choose "Partition" and how many partitions you want usually one volume. Another good article I found on installing on a USB flash drive. Which would be much the same as a Firewire drive.

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I expect you want a minimal system? Help Translate iFixit. Back Answers Index. AussieMac Rep: 11 15 2.