Blocked Processes alarm
Processes can become blocked when they are waiting for: disk I/O completion, network I/O completion, or a shared resource. A high level of blocked processes may indicate an under-configured machine.
CPU Busy alarm
The CPU Busy alarm occurs when the total CPU utilization of the system exceeds a threshold. The CPU may encounter a large number of requests, or you may have un-tuned SQL, which uses excessive amounts of CPU.
File System Space alarm
The File System Space alarm indicates that the file system is full or filling up. If the file system fills up completely, no more data can be written to it.
Memory - Physical Memory Available alarm
The Memory - Physical Memory Available alarm is raised when the available memory drops below a threshold.