[X-Unix] Phantom drive

[Stroller]

On Mar 29, 2004, at 5:28 pm, Phil Dobbin wrote:

> Last night I had a power cut and when the power was restored, the 
> external LaCie FW drive I use for backups wouldn't mount. Console 
> spewed a lot of this:
>
> Mar 29 00:58:52 iMac-Server /sbin/autodiskmount[213]: disk1s2    hfs   
>    yes   yes   Backup           [not mounted]
>
> Mar 29 00:58:52 iMac-Server /sbin/autodiskmount[213]: mountDisks: 
> mkdir(/Volumes/Backup) failed, File exists
>
> Apple System Profiler could see the drive and Disk Utility could see 
> it and verify it and gave it a clean bill of health but it seemed the 
> data on the drive had been lost/corrupted. Based on this assumption I 
> went ahead and did the reformat.

I don't think you needed to format it.
I think from this logfile that when a removable drive is added 
/sbin/autodiskmount detects it, reads the volumename of it and creates 
a corresponding directory in /Volumes. When the drive is unmounted the 
system removes the subdirectory of /Volume.

I think that when your system crashed /Volumes/Backup was not removed, 
so when you plugged the drive in again /sbin/autodiskmount was not able 
to create that directory (because it already existed), This caused 
autodiskmount to exit instead of mounting the volume.

I think that if you'd unplugged the firewire drive and typed `sudo rm 
-rf /Volumes/Backup` all would have been well when you plugged the 
drive in again.

> Now the directory listing for reformated external drive looks like 
> this. `Backup' is the one I lost: `Magnolia' is the new, visible 
> directory.
>
> bash2.05a phil at iMac-Server Mon Mar 29:16:45:32 / $ cd Volumes/
> bash2.05a phil at iMac-Server Mon Mar 29:16:45:51 /Volumes $ ls -aF
> ../        ../       Backup/   Magnolia/
> ...
> What is the best course of action with `Backup' ? Is it safe just to 
> rm it?

I'd certainly risk it. I'd leave the drive unplugged as I did so, but I 
don't think this is a dangerous operation.

Stroller.