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Invalid Nodes, Etc.

My daughter and I enjoyed a fine outing to the park and museum Sunday, but when we came home the house was strangely quiet. No music playing in the living room. No music in the kitchen. Xy said it had stopped a couple hours earlier. I checked my computer, whence the music flows, and it was completely unresponsive. I powered down, but when I powered back up, the system didn’t start. The screen displayed a flashing folder icon, something I haven’t seen in many years — since before the advent of OS X, I’m thinking.

My exact words at that moment do not bear repeating.

After trying a couple tricks without success, I hunted down my Snow Leopard system disk and booted from that, then ran Disk First Aid. The hard drive was looking funky. I tried to repair the disk, and it made a few repairs, but after reporting an “invalid node structure” it crapped out and gave up. A second try yielded even quicker results: “invalid B-tree node size.” The program advised me to backup all data and reformat the drive.

Disk Utility Can't Repair This Disk

A stunned and sickened feeling descended over me as I contemplated the possibility of losing data. That 320 GB hard drive is chock full and has never been fully backed up. I didn’t think it was very important as I tend to put my most important files online in some form or another.

The big exception to that is my music collection. It has taken me years to assemble that, from diverse sources, and there are many tracks that are rare to the point of being literally irreplaceable. I could certainly never recreate that music library from scratch.

And yet, in a strange way, it felt like it could almost be liberating. Curating such a large collection (35K tracks at last count) has consumed a lot of time and attention over the years, especially if you are as anal as I am about meta-data. Occasionally that feels oppressive — as if the collection is managing me rather than the other way around.

Still I was in a state of shock. It occurred to me that I was experiencing the cyber equivalent of either a seizure or a stroke — I wasn’t sure which yet, but I was hoping for a seizure and a quick return to normal.

I called the good old Computer Shoppe, but they are on vacation until next week. The only other option I was aware of was the Apple Store, and I sure didn’t want to go there.

I shelled out a hundred bucks for DiskWarrior. The startup disk is in the mail, but I was able to use my downloaded copy on a laptop to fix my iMac’s hard drive. At first it seemed to work, but the drive continues to have problems, and even when fixed they seem to come back. Must be some bad sectors. I currently can boot up into safe mode only, otherwise I get the “Blue Screen of Death.” And I thought that only happened with Windows. Actually this particular manifestation isn’t even acknowledged by Apple for the Snow Leopard version of OS X. It’s supposed to be a “Gray Screen of Death.” Go figure.

Still, I’m able to boot into safe mode, which is better than nothing. I got a 1TB external hard drive, a LaCie d2 quadra, which arrived with lightning speed from Yesterday I was able to back up the problem drive using Time Machine. Over the Firewire 800 connection, it only took a couple hours or so to archive 300 GB.

So now I have a little peace of mind. I probably need to reformat the drive now and then restore my data from the backup. The prospect of which makes me only a little nervous.

Update: I did try reformatting the drive but it continued to have trouble. A few days after writing this, it seems to have died the death. The iMac is currently at the Computer Shoppe where I expect they’ll replace the drive unless they find something else amiss. I’d love to replace it myself but after reading up on the subject I decided that’s a little much for me.

Published inGeeky


  1. After my first major HD crash (which DiskWarrior was able to fix completely) I became religious about backups. Lately I have two backup HDs, small bus-powered ones. One sits connected to my machine at all times and backs up every night, and one which sits in my desk at work and makes a trip home once a week. Now I feel much more secure, knowing that even if a lightning strike wipes my home machine and backup drive I still have a pretty recent copy sitting off-site not plugged into anything.

  2. HK HK

    You may say this is overkill, but this process has resulted in my retaining 99.9% of all data over the years through various crashes:
    (1) I maintain a Time Machine backup, daily, or hourly or whatever
    (2) About ever couple of weeks, but at least monthly, I do a bootable backup on an external harddrive. I use SuperDuper! (free download).
    (3) Every couple of months, I make a bootable backup to an external HD that is kept off site — in a location other than my computer and other backups.

    This provides a couple things:
    (1) I always have a bootable backup so I don’t have to deal with booting up from a DVD.
    (2) The data on the bootable backup may be a couple of weeks old, but then I just use the time machine to fill in the gaps.

    Once you get this close to losing all your data, you have to capitalize on the fear and institute a process so that you don’t end up here again.


  3. Lee Lee

    Something similar to this is what cause the collapse of ROX season one on DVD. Since then I have become uber paranoid and now have a server that is dedicated to backing up our machines at home daily. I have a raid configuration that makes sure 1 hard drive failure isn’t a big deal. I then use that portable hard drive to back up the backups. I then place vital things in the cloud using flickr and dropbox.

    I think you now understand the feelings that were going through my head when I placed those frantic emails to you. You should have told me about newegg, I’m on their affiliate program. I get a kickback on purchases…..If you want a link I can send it to ya.

  4. Jack Schick Jack Schick

    Thank You so much for this bit of high-dollar-value Intelligence.
    As a recent Macbook user,
    I, and I gather others, have gotten lazy and reliant upon Good MacApple
    reputation (outdated?),
    while I still worry and run through security routines with the old Win2000pro
    when using it.
    I’m going to print down this exchange and learn up.
    Keep it comin’!

  5. Jack Schick Jack Schick

    Also admire your Librarian’s commitment to documentation–metadata.
    I remember first marvelling watching napster-users, then getting some tunes
    myself, and finding things like incorrect Titles and Artists’ attributions to
    famous recorded and radio-played, charted tunes.
    Then I quickly realized: Wow, I used to think I, me, I might get into
    the whole BMI/ASCAP legal game, copyrights and royalties and
    maybe even particularly TV and Movie and Advertising creativity, getting all
    signed up with an Agent and getting SAG and AFTRA membership…
    but Wow!
    everybody and their dog can now get anything that’s digitized for nearly free.
    And that was back in ’98.
    You are contributing to the maintenance of a true Record, a Valuable Work.
    Perhaps you’ll publish this Record?
    Make ’em pay for your authorship.

  6. After noticing that every Mac Forum has someone in it recommending Disk Warrior as an essential buy, I bought it the other day as well, to address a start-up problem. It’s a scary thought when your computer tells you that it may not work again and you might not see your files again. After I lost years of email through a simple mistake, I also got a 1T drive & started using Time Machine.

  7. Hey Bart,

    After having two back-up hard disks crap out in as many years (to be fair, the first one died after my son banged in on the ground repeatedly) I’m in the market again.

    Any reason you went with the LaCie d2? Have you used Newegg in the past?

    I’ll just piggyback on your research.

  8. John-Christopher John-Christopher

    I suspect the problem may be from Entergy’s erratic power supply. You need to get a UPS backup that conditions the power coming into your house. We have a lot of voltage surges that will overwhelm a surge protector after a few nasty jolts. APC makes many reliable devices that will protect your computer and external hard drives. They are available everywhere,, JR&R and even The Computer Shoppe.

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