From a support engineer:
This issue may be caused by some errors on the second partition.
I suggest performing a disk defragment and check disk on the second partition.
If the issue persists, please shrink the partition by 5MB in Disk Management and then extend the partition 5MB back by using diskpart.exe. This will recalculate the partition table entry and correct the values of NTFS total sectors.
Related thread: EV100274 (Backup displays message 0x8078002a).
If the issue still occurs, please understand that here is the Windows Server Setup newsgroup. Therefore, we are not the best resource to troubleshoot this issue. I suggest discussing it in our Windows Server Backup forum: EV100275 (Backup – Windows and Windows Server).
Build a great reporting interface using Splunk, one of the leaders in the Security Information and Event Management (SIEM) field, linking the collected Windows events to www.eventid.net.
Obtain enhanced visibility into Cisco ASA firewall logs using the free Firegen for Cisco ASA Splunk App. Take advantage of dashboards built to optimize the threat analysis process.