"Invalid node structure" message on external hard drive
I am using a MacBook with OSX 10.5.8.
I bought a Lacie drive and have been using it for backup with Time Machine. The USB connection to the drive is loose, to the point that moving it can cause the cable to come loose, therefore essentially disconnecting the drive. This of course brings the ominous message that the drive was not put away properly and might be damaged.
Unfortunately this has happened a number of times. I have tried using Disk Utility to repair the drive, but it can't unmount it so it can't do the repair. I can't dismount/eject it myself, it keeps thinking that there is an application running, although I have quit all open applications that I can see. Tried erasing the drive too, using Disk Utility, same problem, can't erase because it can't unmount the disk.
Tried to do another backup last night and got the Invalid node structure message.
So, the questions are:
Should I just junk this drive and buy a new one?
Is it worth picking up Disk Warrior to try to repair the drive?
Is there any way to figure out what applications or file the computer thinks that the drive is using?
Is there any other way to erase the drive, in the hopes that this would solve the problems?
I am not at all technical about these things so I'm hoping someone might have some help for me.
and are you positive that it's the connection and not the cable itself? with an intermittent connection issue a first step would probably be to swap the usb cable for a different one... and if you still have the issue i'd plug/unplug the cable a few times to make sure there's not a prob with an individual connection point in the connector and from there move to jiggling the connector in the socket...
I can't argue with the recommendation for Disk Warrior; it's an awesome app (and the people at Alsoft are some of the very best people who ever supported a Mac, bar none). If it's "just sitting there" in a CD case somewhere, by all means have at it.
However, it's a paid app, and there are things you can try, that don't cost anything.
Startup from an install disk, and run Disk Utility's repair routines.
Some people are not too high on Disk Utility, because it often reports that a repair cannot be done, or failed in some way.
It's very important to realize that Disk Utility, unlike some "Repair" Utilities, is very, very conservative in it's repair routines. It absolutely will not do anything that cannot be done "safely' in that it won't attempt aggressive routines that may result in an unusable disk if something goes wrong.
Some paid apps (*cough* Norton *cough*) will cause further problems when it's normal process fails to fix the disk, and if that happens, the disk may not be reparable at that point.
In contrast, because of Disk Utility's very conservative approach, it will make small changes and very conservative, non-destructive repairs. However, once one "thing" is fixed, it can build on that "better" disk structure for the next repair attempt.
Eventually, even though it may return errors many times, Disk Utility will slowly make progress in restoring the structure of the disk. Do not take it's "could not be repaired" result at face value and especially do not be afraid to run it 10, 20, or even more times in a row. You may well find that, at some point, you get the "the volume xxx was successfully repaired" result you are looking for.
Once you get the "volume xxx appears to be OK" result, run it one more time. You should get the same result. Good to go.
As a preventative measure, every time you fail to properly unmount the disk (such as your power plug problem; if you have to do a hard restart, etc) run Disk Utility on that volume immediately. Errors are cumulative ... they build upon each other ... it's best to nip them in the bud when you can.
Startup with and Run it from the Install Disk; that way the disk won't be in the middle of writing data, which can happen if it's mounted and you're logged in as a user.
Disk Utility will not do anything that will impair, in any way, Disk Warrior's ability to repair the disk. There is no reason not to run it.
Last edited by gordguide; Feb 16th, 2010 at 04:25 AM.