Storage pool has reached the threshold (80%).

[phipsi]

I got an e-mail with the following content:

Server Name: QNAP
IP Address: 10.4.16.19
Date/Time: 2017/12/30 20:55:39
Level: Warning

[Pool 1] Storage pool has reached the threshold (80%). The current available space is 1.40 TB. Insufficient storage space may lead to decreased performance. Please check the available space or adjust the threshold.

In the General Options > Notifications I have the following setup:
Backup storage warning 10%
Production datastores warning 10%
Skip VM: deactivated

Questions:
Where comes this warning from?
Is there another configuration?

[veremin]

This notification is coming from your storage device, and not from the backup server. So, please check the settings on your NAS. Thanks!

[phipsi]

Thank You very much! Problem solved!