Startup Sequence of Exadata Storage Server

 

Startup Sequence of Exadata Storage Server:

/etc/init.d/cell.d  starts first when system starts

The exadata storage cells operate independently from each other. Cellsrv on each storage server processes I/O  requests via iDB message and independently transmits the return data/messages to the compute(DB) node. It is the responsibility of the compute server to sort, group and process the results returned from each storage server. 

The Management Server (MS) provides a java interface to the CellCLi command line interface, as well as providing an interface for Enterprise Manager(Grid Control) plugins. If MS is down you won't be able to use cellcli.

Process startup sequence  

 - The cellrssrm process is the main Restart Server(RS) process. It launches three helper processes cellrsomt, cellrsbmt and cellrsmmt.

 - The cellrsomt helper process is ultimately responsible for launching cellsrv.

 - The cellrsbmt and cellrsmmt processes are additional helper processes responsible for launching cellrsbkm and the main Management Server(MS) Java process.

 - Cellrssmt is called by cellrsbkm, and its ultimate goal is to ensure cell configuration files are valid, consistent and backed up.

 - And of course, cellsrv is the main process that performs I/O on the exadata cell.