If you have some archive data that you would like to copy onto a win 2012 server, but dont know how to estimate the end volume size (if VM etc). Start small - about 1/2 of the total capacity of the drive. Robocopy the data onto the drive until nearly full, manually run dedupe, wait until complete, continue robocopy, repeat and rinse. There will be occasions where you will run out of disk space at that point its time to extend your disk.
In Windows i use robocopy…
This is the syntax to copy from one location to another… (i like how robocopy uses UNC paths)
robocopy \\192.168.9.70\videos \\192.168.9.101\videos /e /r:2 /w:10 /sec robocopy \\192.168.9.70\software \\192.168.9.101\software /e /r:2 /w:10 /sec
Note: i always copy instead of the move. Run multiple times before switch over to shorten time for final sync. Always use the /SEC to copy over the NTFS permissions. I have had problems with the non X010 version of robocopy not copying NTFS permissions across. Check NTFS permissions before removing the source files. You can update files NTFS permissions with /SECFIX switch if required.