Architecting a vRealize Log Insight Solution : Understanding vSphere Logs : 2.9 Syslog Message Severity
   
2.9 Syslog Message Severity
The log source (such as an ESXi host) that generates a syslog message will specify the severity of the message using a single-digit integer value between 0 and 7.
Table 3. Message Severity Codes
Severity Code
Severity Name
Description
0
Emergency
System is unusable
1
Alert
Action must be taken immediately
2
Critical
Critical conditions
3
Error
Error conditions
4
Warning
Warning conditions
5
Notice
Normal but significant condition
6
Informational (info)
Informational messages
7
Debug
Debug-level messages