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Investigating Host Disk Errors in Mac OS (1037720)

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You see one of these errors in Fusion:
  • Unexpected Signal 10
  • Unexpected Signal 11
  • NOT_IMPLEMENTED bora/devices/mainmem/mainMemCpt.c:1243
  • Unrecoverable Error
  • Operation on file failed.
  • Unable to resume virtual machine
  • Finder error -32


To resolve this issue, you must investigate the root cause of these errors and it involves these steps:

  1. Investigating the host's hard drive for disk errors
  2. Comparing the disk errors with the Fusion error
  3. Attempting to repair disk errors

Investigate the host's hard drive for disk errors

In Mac OS X 10.6 (Snow Leopard) and 10.7 (Lion), you can use the kernel.log file to determine some disk errors. In Mac OS X 10.5 (Leopard), the errors are in the system.log file. To locate the kernel.log or system.log file:

  1. Open Finder.
  2. In the menu bar, click Go > Go To Folder.
  3. Type /var/log and press Return.
  4. Locate the kernel.log or system.log file with the date modified stamp when the error occurred.

    Note: kernel.log is the most recent log, kernel.log.0.bz2 is the one before kernel.log, kernel.log.1.bz2 is the one before kernel.log.0.bz2, and so on.

  5. Double click the kernel.log (or system.log) to open it automatically in the Console application.

    Note: If you double click on a log ending with .bz2, the file is only uncompressed. You must then manually open the file in Console. To manually open the file, right-click the file and click Open With > Applications > Utilities > Console.

In Console, use the search field in the top-right corner of the window to search for the lines that contain I/O. The output appears similar to:

Apr 11 22:04:05 vmware-imac kernel[0]: disk0s2: I/O error

Note: The Macintosh HD boot volume is usually disk0s2. Any partition on the main hard drive is part of disk0 and is called disk0s2, disk0s3, or similar. External hard drives or other internal hard drives begin with disk1s, disk2s, and so on. When those drives are partitioned, the last number increases just as with the main hard drive.

Warning: When you see these errors, ensure that you have current backups of all necessary data on your Mac and your virtual machine.

Compare the disk errors with the Fusion error

These disk I/O errors indicate that there are sectors on the hard disk that cannot be read from or written to and indicate a failing hard drive. Fusion reports errors because the files that it is trying to use are on the bad sectors and cannot be accessed.

Compare the timing of the error messages in the log with the timing of the Fusion error message. You can review the Fusion error by looking at the vmware.log inside the virtual machine bundle. For more information, see Locating the virtual machine bundle in VMware Fusion (1007599).

The log entries with the I/O error are close in time to the Fusion error message. The Fusion crash message may be at a slightly later time than any I/O error because Fusion crashes only after attempting several times to access the disk.

For example:

Apr 11 22:04:21.039: vmx| MMC: Failed to read saved memory '/Users/vmware/Documents/Virtual Machines.localized/Windows XP Professional.vmwarevm/Windows XP Professional-Snapshot4.vmem' with error 'Generic error' (5).

Attempting to repair disk errors

Run a disk repair with the Disk Utility application on the disk that contains the virtual machine (and is showing the errors). Some errors can be repaired, while some cannot be repaired. If errors are found and repaired when doing a repair disk, run the repair again until no repairs are necessary or if you have run it 3 times and still have errors that were repaired. If Disk Utility cannot repair the errors, it indicates an underlying hardware issue.
For more information about using Disk Utility, see the Apple Knowledge Base article ts1417.


error-reported  system-disk-error  I/O-errors

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