How to Recover from Disk I/O Error

J

jwarthman

Junior Member
When cloning my Mac HD to an external, I consistently get an I/O error on one particular file:

/Users/myname/Library/Parallels/Windows 7.pvm/Windows 7-0.hdd/./Windows 7-0.hdd.0.{e97496f9-8179-4a81-963e-db1f1a727c60}.hds

I realize this is inside the Windows 7 virtual machine "package", and when I open the Windows 7-0.hdd package I can see the file.

Are .hds files part of Parallels snapshot feature? I have several in this package, and the one causing the I/O errors is not the most recent. Can I delete it safely?

Or is there something different that I should do to eliminate this I/O error?

I am running Mac OS 10.6.8 and Parallels Desktop version 7.0.15055.740667.

Thanks!
 
Update

The plot thickens...

I used "Manage Snapshots..." and found that it's the most recent snapshot that has the I/O error. I tried creating a new snapshot, and Parallels gives an error: "Operation failed. An error occurred while reading the disk. Problem ID 21029. The corresponding KB article says "Parallels Desktop failed to perform an operation due to errors on the Mac hard disk." and has instructions for repairing the disk using the Apple Disk Utility.

Before I try Disk Utility, I decided to revert to an earlier snapshot. But I get the same error from Parallels when I use Manage Snapshots to revert to an earlier snapshot. This makes me wonder how effective the snapshot facility is! If I have a corrupt VM, but the corruption prevents me from switching to an earlier snapshot, what have I gained by using snapshots?

UPDATE:
I called AppleCare, and they believe it's a simple case of a corrupt file, not a failing hard drive. Apple recommends that I delete the specific file that has the issue. I suspect that would cause issues with Parallels, so that sounds like a Bad Idea.

I thought I might be able to replace it with a Time Machine backup, but I realize that I would have to replace the entire Windows 7.pvm file because Time Machine won't let me replace individual files that are inside that package.

My preference would be to use Parallels Manage Snapshots to get rid of the bad snapshot, but that gives the I/O error.

Anyone have ideas?

Thanks!
 
Last edited:
Hi, did you ever find a solution for this? I'm facing exactly the same situation and desperately need my data. It had not been backed up with Time Machine because I mistook how the snapshots worked and selected "Do not backup virtual machine" on the VM Backup configuration.
 
dd

had the same problem.
found a solution that worked for me.
find the .hds that is corrupted.
use the dd error tolerant copy command:
dd if=corrupted.hds of=newfile.hds conv=noerror,sync
rename the new file to the old name.

my best - re-book
 
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