Windows Server 2012 Standard and higher editions provide the optional Data Deduplication feature for data volumes formatted as NTFS. Retrospect 8.5 for Windows and higher and Retrospect 10.5 for Mac and higher support backing up from such volumes with NTFS Data Deduplication enabled.
Currently when backing up the boot volume of a Windows Server 2012 system that has data deduplication enabled on a volume, Retrospect’s snapshot of the boot volume can be very large (up to several hundred Gigabytes). You will need to follow the steps below to prevent Retrospect from creating a large snapshot:
Open up Notepad.
Hit Ctrl-m to create a carriage return, type "Dedup Writer", hit Ctrl-m for another carriage return, then select all. Use Ctrl-c to copy the text to your clipboard.
Within Retrospect, you will need to hold down Ctrl-Alt-p-p to access Secret Preferences. There, you need to go to "Open File Backup", in the "Excluded writer list", you need to paste the contents from Notepad. If done correctly, the "Dedup Writer" should be listed below MSDEWriter and not on the same line.
Last Update: April 30, 2015