RAC Background Processes
There are few additional background processes associated with a RAC instance than you would with a single- instance database. These processes are primarily used to maintain database coherency among each instance. They manage what is called the global resources:
1)LMJON: Global Enqueue Service Monitor
2)LMD: Global Enqueue Serv ice Daemon
3)LMS: Globa] Cache Service Processes,
4)LCK: Lock process
5)DIAG: Diagnosability process
At the cluster level, you find the main processes of Oracle C’Lusterware. They provide a standard cluster interface on all platforms and perform high-availability operations. You find these processes on each node of the cluster:
1)CRSD and RACGIMON: Are engines for high-availability operations
2)OCSSD: Provides access to node membership and group services
3)EVD: Scans callout directory and invokes callouts in reactions to detected events
4)OPROCD i Is a process monitor for the cluster (not used on Linux and Windows)