Problem scenario
You have heard about different operating system events being classified in different levels. Lesser events can be captured with logging is verbose. Major events can render a system useless. You know system logging is normally done in a file called /var/log/syslog. How do you find out which levels there are from most significant to least significant?
Solution
Use this command: man syslog
Search for the word "level" by typing this: /level <press enter>
Below is what we found from the man page for syslog on a Linux server (except the #* comment):
LOG_EMERG system is unusable
LOG_ALERT action must be taken immediately
LOG_CRIT critical conditions
LOG_ERR error conditions
LOG_WARNING warning conditions
LOG_NOTICE normal, but significant, condition
LOG_INFO informational message
LOG_DEBUG debug-level message
#* Professionals remember the order of significance with the mnemonic "do I notice when evenings come around early?" If you can remember what happens after the summer solstice, you can remember the levels of significance of the descriptive Linux logging designations.