Working around the 8 GB installation limit: part 2

FireWire enclosures Several readers have asked if they can use an external FireWire enclosure (yesterday's case report used a USB enclosure) to temporarily house their internal ATA drive an avoid the 8 GB partition installation limit. The answer is yes, though some Mac models do not support FireWire booting.

Check Knowledge Base article #58606 for a list of Macs that can boot from a FireWire-connected drive.

Can cause boot problems Working around the 8 GB installation limit can cause boot problems under some circumstances. Matt Austin writes:

"While working around the Mac OS X 8 GB installation limit can get people to install X on drives they can't or don't want to reformat, it can cause the computer to not boot if any file of the operating system needed at startup is outside of the first 8GB."

"What would happen is the installation and boot process would work fine. in fact, there would be no issues until the first 8GB had been filled with files. After that the mac would fail to boot as soon as an operating system update was applied, as the update wrote files outside of the first 8GB."

It should be noted that this is not a problem if you are completely sure that all files needed by the earliest part of the boot process are within the first 8 GB of the disk. However if that drive is then used for a while, and for any reason any of these required files end up being moved beyond that 8 GB address limit, then some systems will stall during the boot process.

So no matter what you decide to do, approach this work around with caution.

Insight on this issue? Drop us a line at late-breakers@macfixit.com.

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