# Hard Drive giving Invalid Sibling Link Errors!?!



## bgw (Jan 8, 2008)

My iMac boots, but I can't run the finder or see the hard drive. I just get the menus and dock. When running the Disk Utility I get 'Invalid Sibling Link' errors. I tried a few solutions I found on the web, but none helped. Are there any other things I might try before I get a new hard disk?


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## Paddy (Jul 13, 2004)

Exactly what things have you tried so far? It's a little difficult to suggest what to try next if we have no idea what you've done already. 

Do you have a current backup? (If not, this should be the ultimate wake-up call, unfortunately...)

Have you've tried the various solutions found in articles like this?

A possible fix for invalid sibling links on a hard drive - Mac OS X Hints 

Note: read the entire thread and all warnings therein.

Do you have Disk Warrior (I'm guessing not?)

http://supportdb.alsoft.com:591/FMP...tml&-script=counter&-token=183&-Skip=96&-find

Posting this link more for the info about what an "invalid sibling link" is than anything else. (I'd suggest you get DW - it has saved my bacon a few times and I consider it essential) However, as more or less hinted at in that response, DW might not be able to fix this either. However, some have had success:

Apple - Support - Discussions - invalid sibling link, drive with osx ...

If you've tried the solutions in the Macworld/OSX Hints thread and nothing has worked, don't have DW and cannot wait to get it and try it, then one alternative you may want consider is to wipe your drive and start over - assuming of course that you HAVE a backup/can rescue the data on the drive before doing so. If you can use Firewire Target Disk Mode from another Mac, that would be ideal, if you don't have a backup and need to recover the data before wiping and reformatting the drive.


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## bgw (Jan 8, 2008)

Ya, I've tried to get the machine going with variants of:


```
fsck_hfs -r /dev/disk0s2
```
but no luck so far. 

I have backups of all the really important stuff (work related) so I can reformat the drive. My concern: 

1) Is this a actual fault on the drive? Then I get a new drive.
2) Has the OS messed up, and the drive is fine? If this case I'll wipe and start again.

Which of these two paths should I take?


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## Paddy (Jul 13, 2004)

These are directory errors - your HD has lost or scrambled some info in the directory. An analogy: It's as if you went to the public library (in days of yore, when they had physical card catalogues) and went to the card catalogue and someone had taken one of the drawers out and turned it upside down. The books (your actual files) are still in the library, but you don't know how to find them because the cards which give you the Dewey Decimal numbers to locate the book aren't where they belong in the card catalogue. 

Anyway, the directory errors will most likely be resolved by erasing the drive and starting over, but they _could_ be an indication of the drive going bad and may recur. You need to keep an eye on it. Disk Warrior also might be able to resolve them - again, I'd strongly suggest that you consider buying it. Alsoft suggest that you run it once a month, though I've never done that, but know of some who swear by it. In an emergency when DU doesn't cut it, unless the drive is truly dying (which has happened a couple of times), DW has saved me and it's a lot less painful than having to reinstall everything, even with backups.

Apple - Support - Discussions - Sibling Link Errors ...

You have been booted into Single User Mode when attempting the fsck fixes? See:

How to fix the Invalid Sibling Link error : Mahal kita for an explanation of why this is necessary.

As for why directory corruption happens, there are a number of causes, but often you won't know why it happened. It just did. Some of the more obvious causes are bad sectors on the HD (which can get worse over time with use), shutting down improperly (pulling the plug or hitting the power button when you could have shut down normally), removing external drives improperly etc. 

Sometimes directory errors are the first indication that the drive is going bad. Certainly I've had that happen. Other times, it's just something that got out of whack and running DW cures it. And sometimes those errors can produce some really alarming symptoms, and yet be really easy to fix, either with DU or more often, Disk Warrior and they never recur.

If your drive has any other symptoms, such as taking an inordinate amount of time to start up or do anything (and it isn't completely full to capacity!) then I would consider replacing it because it may well be failing. If this is a one-off problem and wiping and starting over solves things, then keep an eye on it, make a CLONED backup every night (use SuperDuper or Carbon Copy Cloner) and chances are, you'll be fine.


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## bgw (Jan 8, 2008)

Since the machine is old (4 years) and the error has occured in a boot sector, I'm going to take the machine in. The rescue software, for the most part, will run the identical Unix commands that I've been trying. While I'm at it I'll get a larger drive, and the memory upped. I've got a iPhone app to fix (some really bad bugs in it!) and two websites to enhance by Monday. The tech said that the drive replacement would take an hour, and I'll put the old one in a case and use it as a slightly unreliable backup drive! Possibly with a reformat, the bad sectors will be locked out of my main drive.

Thanks for your help Patty. I'll write a summary when I'm done. I think you'll be interested in how the drive performs after it has been reformatted.


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## bgw (Jan 8, 2008)

Follow up...

Thanks again, Paddy, for your help. I have a new drive in the machine (1 TB) and I restored the machine using Migration Assistant. As far as I can tell I got everything back. :clap:

I have created a Windows XP partition with Bootcamp and am now debating if I should get everything off my old Bootcamp Partition. Presently I am setting up XP just for work related activities.

I also upgraded my memory from 2 GB to 4. Most of the time one doesn't notice the difference in memory, but every now and then you can really tell the difference. I can now run multiple virtual machines!

At this point, all is well.


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