How long does it take to backup Windows server 2016 files?

Question

Backup

Good afternoon!
The situation is as follows, the other day there was an update of windows server 2016, and after that, files from the file washer began to be backed up for a long time, the volume of files was 2TB. Estimated backup time every day: from 15 00 to 11 am the next day ... who faced, what was treated?

Answer 1

In general, there is a lot of unclear what kind of system where backups are made, what, etc.:
As an option:
1. Check disks or raid (no out of sync, etc.)
2. Backup to this disk or over the network?
3. Have a lot of small files appeared?
...