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
Got questions? Get answers!

Join the Splunk Community Slack to learn, troubleshoot, and make connections with fellow Splunk practitioners in real time!

Meet up IRL or virtually!

Join Splunk User Groups to connect and learn in-person by region or remotely by topic or industry.

Get Updates on the Splunk Community!

Painting a Clearer Picture: Creating Cross-Domain Visibility with AI Canvas

    Thursday, June 25, 2026  |  11AM PDT / 2PM EDT  Duration: 1 Hour (Includes live Q&A) Register to ...

Analytics Workspace deprecation

As of Splunk Cloud Platform 10.4.2604 and Splunk Enterprise 10.4, Analytics Workspace is now deprecated. ...

Splunk Developer Day Recap: Building, Publishing, and Growing on the Splunk Platform

Splunk Developer Day brought the Splunk developer community together for a practical look at what it means to ...