What command should I use to check spluk logs in a linux system?
And where should I run this command?
In Splunk : search for "index=_internal" - This will give you all internal Splunk logs on your instance(s).
Alternatively, and old school, you can look in the $splunk_home$|/opt/splunk/var/log/splunk/ folder and grep through the logs.
This "logs" you're talking about, are they the one to check the state and errors in your Splunk instance? Or are they something else?