Personal Bytes

Wow. This was something.

What happened dude?

It all begun yesterday. I started feeling sick and the cough and fever were chasing me like hell. Next day (today), I woke up fairly bad and unable to work. The best I could do would be standing still in front of the TV watching the news. Even movies were too much for me. Unable to work, I decided it was time to take care of less relevant things — like finally upgrading my Macbook to Leopard.

As you clearly shouldn’t do, I decided that doing a backup was too boring. 100GB of data would take quite some time and my boredom levels wouldn’t permit it. Absolutely unwise! And I had all the relevant data stored on my server anyway — so, a failed upgrade only meant installing tons of applications, MacPorts, tuning the system, restoring data.

So I went forward with the unwise decision of skipping the backup. But when you’re sick (and even when you’re healthy) you can do dumb things. Twice. In a row.

I popped in the Leopard DVD and I did my second mistake: skip the verification of the DVD. Guess what? Yes, the DVD was scratched. So during upgrade it suddenly aborted upon a failing checksum. Oh boy, I was mad.

The DVD was indeed scratched. I should have noticed before or at least have waited for the checksum to finish. Result? A dead system.

Did you give up and did an Erase and Install?

That thought popped through my mind. But I’m not an easy quitter. That would be the easy exit.

Although I don’t have that much knowledge of the Mac OS X installation process, it couldn’t differ that much from the *nix world — run a couple of scripts, delete some files here, add some files there and update configuration files. Therefore, a deterministic process. This would mean that repeating the process would work.

Considering this, I created an image of the DVD and burned it on a blank dual layer DVD. Sticked it in and did an upgrade. Again.

It went through. This was a fresh, blank DVD so no way in hell it could have scratches. Restart. Cross Fingers.

Now what?

Oh, the joy of an endless wheel spinning around. After 15 minutes on the grey screen with the Apple logo and the spinning wheel I realized it was a dead end. Something was wrong. Google to the rescue.

First, I tried doing a safe boot. Wouldn’t work. Then I tried a verbose boot to see whether the kernel was panicking. It wasn’t, but somehow the boot process was failing. It could be due to a kernel extension from the prior system that was causing some incompatibilities. Let’s take care of that.

I found this really helpful article. It explained how to remove some caches or disable some kernel extensions. Thanks to the microkernel nature of Mac OS X’s Mach kernel, doing it was fairly easy.

But it didn’t solve the problem. The system was still not booting.

So, you gave up and did an Erase & Install

Wrong. I couldn’t settle with such mess and resort to the easiest exit: format and install. That’s too Windows-ish.

So I decided to do another upgrade install. Some third-party kernel extensions were disabled and it might work now.

Installation went fine and the system finally booted up to a login screen. Tcharam.

Done!

Not quite. My user account was gone. Actually, my user’s folder was still there, my I was unable to login with my username. Vanished to the confinements of /dev/null. Off we go to another reboot, this time in single user mode.

While in single user mode, I’ve activated the root account so I could login to the system. $ sudo passwd root did the trick and in a couple of minutes I was logging in into Leopard’s root account.

From there, I just re-created my user account. It detected my user home folder and imported all my settings — from the background image to the icon disposition.

Lessons from a turd to you kiddos

Ok, what did we learn today? Backup. Really. If I had done a backup with SuperDuper! I could easily restore the system up to a bootable state and then just repeat the installation process this time with a workable DVD.

But if you’re too lazy to backup (now seriously: I only did this because all important data is stored on my home server — NEVER, and I mean, NEVER, do this) at least check that the friggin’ DVD is working.

Fortunately this had an happy ending. I’ve just installed 10.5.2 and everything seems miraculously fine. As Lou from Little Britain would have said: “What a kerfuffle!”