Mac – Error installing Mac OS X 10.10 (Yosemite) on a 512GB SSD in the 2010 MacBook

macbookosx-yosemite

The Mac OS X 10.10 (Yosemite) installer fails to extract any files onto my drive:

OS X could not be installed on your computer

An error occurred while extracting files from the package "Essentials.pkg".

Quit the installer to restart your computer and try again.

However, I have reinstalled Mac OS X 10.9.5 (Mavericks) just fine, which leads me to believe there’s something wonky going on with the installer.

Judging by the comments on this other question, it seems like this error might be occurring with people who have installed SSDs in their old MacBooks. I have a mid-2010 MacBook with a 512GB SSD in the main hard drive slot and a secondary 250GB HDD in the DVD drive bay. I also have installed 16GB of RAM in this laptop. So far all of the new hardware has worked fine for the past 6 months so I doubt my issues are due to faulty hardware. I am trying to perform the install on a freshly formatted partition.

Here is the install log.

Here’s another install log from when I was trying to upgrade the OS instead of using a freshly formatted partition.

Best Answer

Trim kext is altered in Yosemite. This is not relevant if you're using an Apple installed SSD. If you're using a DIY SSD, Trim support is tricky in Yosemite because of recent modifications to kext security management that affects Trim support. More about Trim Enabler for Mac.

About Trim in Yosemite In OS X 10.10 (Yosemite),

Apple has introduced a new security requirement called kext signing. (A kext is a kernel extension, or a driver, in Mac OS X)

Kext signing basically works by checking if all the drivers in the system are unaltered by a third party, or approved by Apple. If they have been modified, Yosemite will no longer load the driver. This is a means of enforcing security, but also a way for Apple to control what hardware that third party developers can release OS X support for.

Since Trim Enabler works by unlocking the Trim driver for 3rd party SSD’s, this security setting prevents Trim Enabler to enable Trim on Yosemite.

To continue to use Trim Enabler and continue to get Trim for your third party SSD, you first need to disable the kext signing security setting.

It is important to note that the kext-signing setting is global, if you disable it you should be careful to only install system drivers from sources that you trust.

Some drives work without Trim enabled: ZDNet on issues with Trim in Yosemite.

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