While investigating the cause of intermittent snapshot failures, the following event is found in the protected Agent machine's System Event Logs:
Log Name: System Source: volsnap Date: 8/15/2014 12:22:22 PM Event ID: 14 Task Category: None Level: Error Description: The shadow copies of volume C: were aborted because of an IO failure on volume C:
This error indicates that the protected disk may be failing, and specific NTFS and Disk warning and error events may be present. Certain aspects of VSS will prevent a snapshot from performing on an inconsistent disk. Some transfers may succeed and these errors may appear to be transient.
1) Schedule a chkdsk /f /r on all volumes on the disk. If chkdsk comes back clean and continue to the other steps.
2) Verify that the system is patched up with Windows updates and that the storage controllers have updated drivers and firmware
3) If you have other disk scanning tools available from the disk manufacture, these can be used to verify if the drive is not failing as the above error could be an indication of a failing disk