Plesk sends notification about limit overuse, while domain does not exceed it

Symptoms

The following notification is received:

CONFIG_TEXT: Limit has been exceeded on domain 'example.com'

but no limitations are set for this domain in it's service plan (Service Plans > <service plan to which domain is assigned to> Resources). 

In Tool & Settings > Action log, the following is shown for the example.com:

CONFIG_TEXT:  'MSSQL database soft quota reached' ('Microsoft SQL database quota': '' => '178257920', 'Microsoft SQL Database Usage': '' => '191234048', 'Domain Name': 'example.com'

Cause

MSSQL database soft quota reached. By default, it is 85% from the overall limit, so in case the limit is 200 MB, notification is sent when database size > 170MB.

Resolution

Increase the limit for the MSSQL quota, or adjust the notification limit:

The soft limit can be changed in panel.ini.

To correct it, do the following:

1. Log into Plesk;
2. Open panel.ini file using Panel.ini editor extension;
3. Specify the option databaseManagement.diskSpaceSoftQuota. The value is the percentage of the limit (default is 85%). For example:

CONFIG_TEXT: [databaseManagement]
diskSpaceSoftQuota=50

Additional Information

Administrator's Guide: Event Parameters