Backup ETA Keeps Increasing at the End

Scenario

Running backup job has time remaining being increased till some moment near the end of operation, while it is expected to decrease.

Reason

Backup estimates are based on current speed of the process and are provided for general reference only.

Solution

Focus your attention on progress of operation (blue thin line) instead and ignore time remaining information, because it is correct only when about 90% of operation is done.