Alerting

How to create an alert for disk usage?

uchoavaz
Explorer

Hello!

 

i am sending from a host to splunk cloud logs from the disk usage. Here is an example how the events are:

 

 

 

/dev/nvme4n1p1	xfs	50G	555M	50G	2%	25M	33K	25M	1%	/var/www

 

 

 

 

where "2%" field is called as "Use_". How can i create an alert/search when this number (without the percentage symbol) is higher than 80 ?

 

Thanks!

Labels (2)
0 Karma
1 Solution

gcusello
SplunkTrust
SplunkTrust

Hi @uchoavaz,

you have to extract the remaining disk space using a regex and then cheate a condition:

index?your_index
| rex "^(?<device>[^ ]+)\s+\w+\s+\w+\s+\w+\s+\w+\s+(?<disk>\d+)"
| where disk>80

You can test the regex at https://regex101.com/r/3W8h6m/1 

Ciao.

Giuseppe

View solution in original post

0 Karma

uchoavaz
Explorer

Worked! Thanks.

0 Karma

gcusello
SplunkTrust
SplunkTrust

Hi @uchoavaz,

you have to extract the remaining disk space using a regex and then cheate a condition:

index?your_index
| rex "^(?<device>[^ ]+)\s+\w+\s+\w+\s+\w+\s+\w+\s+(?<disk>\d+)"
| where disk>80

You can test the regex at https://regex101.com/r/3W8h6m/1 

Ciao.

Giuseppe

0 Karma

uchoavaz
Explorer

@gcusello i have an issue here with this regex... it is not filtering  this type of event:

/dev/mapper/group1-mountpoint_www	xfs	9.0G	674M	8.4G	8%	4.5M	33K	4.5M	1%	/var/www

 

basically what changes is the filesystem name (uses "-" and "_") and the size of the numbers and the sizy (M, G, K).

 

PS: I know that in your example the disk needs to be higher than 80, but i changed the value to 2.

0 Karma

gcusello
SplunkTrust
SplunkTrust

Hi @uchoavaz,

please try this:

index?your_index
| rex "^(?<device>[^ ]+)(\s+[^ ]+){4}\s+(?<disk>\d+)"
| where disk>80

that you can test at https://regex101.com/r/3W8h6m/3

Ciao.

Giuseppe

0 Karma

uchoavaz
Explorer

I know that the issue is at the dot (".") that can exist or not in the column 3,4 or 5. But how can i put that in the regex?

0 Karma
Get Updates on the Splunk Community!

App Platform's 2025 Year in Review: A Year of Innovation, Growth, and Community

As we step into 2026, it’s the perfect moment to reflect on what an extraordinary year 2025 was for the Splunk ...

Operationalizing Entity Risk Score with Enterprise Security 8.3+

Overview Enterprise Security 8.3 introduces a powerful new feature called “Entity Risk Scoring” (ERS) for ...

Unlock Database Monitoring with Splunk Observability Cloud

  In today’s fast-paced digital landscape, even minor database slowdowns can disrupt user experiences and ...