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Mac Disk Failure & Recovery

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The first time I had a major failure on my Mac Pro, I lost a 1 TB Seagate drive and ten key virtual machines. It taught me to apply the principles from my production life to my private life. Swapping the fault-prone Seagate drives for Hitachi drives, I began the slow process of rebuilding those virtual environments.

My solution to minimize risk was two fold. First, I put the main 320 GB disk on a time machine backup. Second, I began weekly backups of my virtual machines to two external 2 TB disk drives. After all, I wanted to contain cost.

Paying more attention paid off this week, when I got the flashing drive folder error. It’s the equivalent on the Mac OS X to Microsoft’s Blue Screen of death. This error means the machine can’t find a healthy OS. The problem is that there a number of posts out there, and some aren’t as effective as they appear in solving the problem. More or less, when you see this screen you have two tests before getting a new disk and restoring the image from your time machine.

The first step requires you to reboot the machine that’s stuck looking for an operating system. You can do that by pushing the power button until a reset occurs while simultaneously holding down the Option and key. You’ll know it works if you don’t see the blinking file folder icon and you see a mouse arrow displayed in the screen. It should occur within 5 to no more than 10 seconds after you reboot.

Insert a valid Mac Operating System (OS) disk into the optical drive. It should launch the installation program within 30 to 60 seconds. Click the first proceed button and on the next screen launch the Disk Utility from the displayed menu. In the Disk Utility, click the First Aid tab. Look at the Total Capacity value in the bottom right of the screen. If it provides a numeric value, there’s a hope for your disk recovery. Click on the First Aid tab to try and recover the disk drive. If it provides a zero numeric value, there’s virtually no hope for your disk recovery.

Since the likelihood of recovering the disk at this point is low, buying a new disk is probably the best step. After you’ve ordered the replacement disk, you can boot your Mac in target mode. Target mode allows you to use another Mac and it’s operating system to run your disks (on a Mac Pro, there can be up to 4 disks).

Remove the CD copy of the operating system from the optical drive and push the power button to turn off your non-working Mac. Start the remote Mac and connect the two using a FireWire cable. After the new target machine has finished booting its copy of the OS, push the power button on the machine that can’t find the OS and hold down the T key. In the target machine, open the Finder and inspect which disks are found. If the base disk drive is excluded from the list, as it is in the screen capture on the right, your disk has failed.

At this point, you should definitely buy a new disk unless you’re covered by AppleCare. If the latter, log a ticket and let them fix it. It’s even possible they may be able to recover something from your failed disk. Although, it is unlikely your get any data back if the Mac OS X software can’t recognize the disk.

Your best bet is to recover the image from a time machine restoration. Hopefully, you had an active time machine image not too far before the failure. I did, and it fully recovered everything smoothly. The new disk arrived this morning, and I’m less than 30 minutes from a full recovery. Though that’s unimportant unless I tell you how.

Once you physically install the disk, you reboot the machine that’s stuck looking for an operating system. You push the power button while simultaneously holding down the Option key. Insert a valid Mac Operating System disk into the optical drive. It should launch the installation program within 30 to 60 seconds. Click the first proceed button and on the next screen launch the Disk Utility from the displayed menu. In the Disk Utility, click the Partition tab to partition the new disk. Then, choose to restore from a time machine in the installation program.

Bottom-line: I’m so happy that time machine works so well!!!

Written by maclochlainn

December 8th, 2012 at 6:07 pm

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