By Graham K. Rogers

When I went into the office on Monday I tried to wake up the iMac I keep there I pressed a key and the spinning wait cursor appeared. Instead of getting to work, the cursor kept on spinning. When I tried to restart the computer things went from bad to worse. When running some checks, I saw that the S.M.A.R.T. status reported that the disk was failing.

I was fairly sure that the iMac was on its last legs, but we must never give up hope, even though I a new hard disk had already been ordered. When I had a chance on Tuesday, I inserted the 16 GB "Rescue" flash drive that I carry and started the iMac while pressing the Option key. That displays any bootable partition that can be found: there were four. The original OS X installation on the iMac hard disk; the Rescue partition on the iMac (access using Command + R) and two partitions on the flash drive. I selected the one marked Rescue that had the USB icon on it and pressed the Enter key.

This is always slow. Accessing OS X via USB is not the quickest way to make things happen, but I knew it would work. Once the system was available, I went straight for Disk Warrior and ran that. The progress bars displayed as it went throuhg its checks were encouraging, but in the end this was a false hope. The disk really was dying.

Disk Warrior reported a list of problems, but at the top was the warning that the disk was unusable so Disk Warrior would not be creating an optimised desktop for me after all. What it does, however, is to create a virtual hard disk and this was available to me in the Finder. A note in the report showed me that all data was easily accessible. Lucky me.

Because of the problems, I was ready with an external hard disk in the office (I should have used that to run Disk Warrior). I connected that to the iMac and considered the options. I could have copied the entire structure to the disk, but was dubious about the amount of space available. With a new disk (on a spare computer like the iMac) I would be able to build the installation from scratch. On a computer I use for work, I would want to be up and running as soon as possible.

What is more important is the data: applications can be reinstalled. I decided to copy the home folders of three accounts on the installation and use them (and their data) as part of the future disk install. It would be slow, but the data would remain intact.

I highlighted the three folders in the Users folder -- one for each account -- and dragged them onto one of the partitions of the hard disk. There are three: a rescue partition as I have on the Mac (accessed by the Command + R combination at startup), a partition with a basic installation of OS X, with enough utlities to effect repairs, and a partition of around 220 MB for storage. I used that.

The Finder indicated that the task would take some 7 hours. I went to teach and came back 3 hours later, with another 2 hours to go (Apple time is variable). I left this to complete its task and went home. While I had been out of the office, the department technician had accepted a new hard disk for me: a 500 GB Toshiba for 2,410 baht.

By the next morning the data was copied to the external hard disk and I shut down the iMac. The chief of our technicians was ready to install the new hard disk: a task he has done on countless PCs over the years. However, he was trumped by access to the components. A Thai site that details how to carry out repairs (a local version of iFixit) indicated he needed 6 suction tools to remove the glass screen: he only had two.

While I was waiting to meet visitors to the Faculty (aborted to my great annoyance) he and another technician, took the iMac over to the uStore with the new hard disk. When this is ready, I will pick it up and start the rebuilding of the installation, probably beginning with another download of OS X, 10.7 Lion. This may be completed by the time OS X 10.8, Mountain Lion arrives.

See Also: Hard Disk Failure on the Office iMac

Graham K. Rogers teaches at the Faculty of Engineering, Mahidol University in Thailand. He wrote in the Bangkok Post, Database supplement on IT subjects. For the last seven years of Database he wrote a column on Apple and Macs.