I'm running Windows Server 2012, with my "C" drive on a small, 60 GB SSD and a large, 3 TB drive as my "D" drive, with two VMs on "D" (only one VM runs, the other's turned off all the time). In the past I've had no problem using Windows Server Backup to do an initial Full backup of all drives, with scheduled daily incremental backups, to another 3 TB HDD. However, recently I formatted the backup 3 TB drive and started over (dumb thing to do). After the initial, full backup (System Reserved, Bare Metal Recovery, C, D, Hyper-V, Virtual Machines), all subsequent backups do System Reserved and Local C as incremental, but the large "D" drive, 3 TB HDD (with about 2 TB of data on it) is always done as Full, and it takes six hours. It used to do "D" as incremental and would take a few minutes, depending on how much data changed that day.
I have tried configuring Performance Settings to Fast, which is supposed to backup changes only, yet each night a full backup of "D" is made. I've also tried configuring Performance Settings as Custom, and forcing each drive to be Incremental in the drop-down box next to each drive, but it makes no difference: "D" is always a full backup. The time taken isn't the biggest problem -- the biggest problem is that I have no backup history. A file deleted yesterday is gone for good without incremental backups.
Does anyone have any idea why Windows Server Backup will not backup my 3 TB "D" drive (with 2 TB of data) incrementally? I used to be able to hold over a dozen backup copies before, now all I get is yesterday's data.
Mike B.