What is the difference between DMC and SSH free disk space?

[guimilare]

Hello Splunkers.

Today I saw a curious issue after receiveing a splunk alert os low disk space (lower than 10%).
In the Monitoring console, I can see why the alert was fired:

However, when I go to SSH and do a df -h, this is the result I get:

This would give a 20% free space in disk and the alarm would not be fired.

Any thoughts why this difference between Monitoring Console and SSH is happening?

regards,
GMA