Windows Server 2022 Backup is always doing Full Backup and never doing Incremental Backup on data volume

Question

As in title, my Windows Server 2022 is always doing full backup and not incremental backup.

I've checked this 10 year old question Windows Server Backup, drive is doing full backup instead of incremental but there was nothing that can help me.

Additional Info:

1. Software: Windows Server Backup on Windows Server 2022 version 21h1.
2. Backup is done to an external 4TB hard disk drive. (No network)
3. Performance option is set to do faster backups.
4. I tried setting performance options to custom and then explicitly selecting the drive that has the data to do a faster backup which I assume is incremental. But it keeps on doing a full backup.
5. I tried both VSS copy and backup options, still doing full backup.
6. I recreated the schedule about 10 times, still doing a full backup.
7. The same configuration backs up the C drive as incremental, but data volume still doing a full backup.
8. I did manual backup; it keeps on doing a full backup.
9. The backup external disk drive was configured to be dedicated for backups, it was doing full backup; when I change it back so that backup is configured to backup on a volume, it did a full backup as well.
10. My data size is ~950GB and I can't let the server busy all day just doing backup while it has more important things to do.
11. I've done this before but on Windows Server 2012 and it did a full backup the first time, and then subsequent backup operations were incremental which is the intended behavior.

I would really appreciate it if you could help me.

Answer 1

Check the Volume Shadow Copy service, it should be enabled.