[Macpartners] Serious, recurring disk navigation problems: Help needed

[Quentin Smith]

On Fri, 20 Jul 2007, Susan Midlarsky wrote:

> Setup:
>
> Macbook Pro, 1st gen, 100 gb HD
> Tibook FW, 60 GB HD
> Iogear 320 GB external HD
> 6 GB mini external HD
>
> My MBP's hard drive went nuts last Friday, exhibiting all kinds of
> corruption. It was unrecoverable using the standard tools, including
> Diskwarrior. On inspection and attempted recovery with Data Rescue
> II, all the directories inside the User directory showed as size zero
> bytes, though the amount of free space was consistent with the files
> still being there.

My first question would be, are you using FileVault? FileVault is known to 
break in horrible ways.

<snip>

>
> Trying to rebuild the directories using Diskwarrior shows up
> something even odder. When rebuilding, previewing the old and new
> directories allows me to browse through and see the files that are,
> indeed, there. However, as soon as the rebuild is done, I can't see
> the contents - Finder shows them as zero bytes.

If my hypothesis below is correct, that's because DiskWarrior mounts the 
drive with permissions ignored and then when it's done with permissions 
observed.

>
> Tried navigating using Terminal, but hitting the zero directories
> returned a permissions error. Tried rebuilding perms; no use. Sudoing
> to the directory just bounced me back to the previous directory.

Repairing permissions does not touch any files in users' home 
directories; it only checks/fixes files that were installed by the OS. One 
way to check this (though be careful!) is to enable and log in as the root 
user. Open /Applications/Utilities/NetInfo Manager.app and choose 
Security->Authenticate, then Security->Enable Root User. If it hasn't 
prompted you for a root password and you don't know it, also choose 
Security->Change Root Password.

Then you can log into the machine with the special username "root". Root 
is god on a Unix machine such as your Mac; if root encounters permission 
denied, then something is seriously wrong with your drive. If root is able 
to see your files, you can use Get Info to change the owner and 
permissions back to your user account.

>
> So now I'm stuck. What is making these directories unviewable? I'm
> started from a different machine, different file system, rebuilt
> directories, etc. If you have a clue, please pass it on - the more
> technical the explanation, the better!
>

Hope this helps,
--Quentin

>
> Thank you!
> Susan