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Listing processes on a UNIX system

You can use the UNIX ps command to generate a list of running Oracle processes. The way this is generally done is to use
ps -ef
to see an extended process status listing, and then grepping for the processes of interest. For example, it's very common to run multiple instances on the same server, and if you are not sure which instances you have running, you can find out by grepping for database writers. Every instance has at least one database writer, so you are sure not to miss any Here's an example:

$ ps -ef | grep dbw0
oracle 2564   1  2 07:00:01 ?     0:05 ora_dbw0_test
oracle 2588   1  2 07:00:05 ?     0:05 ora_dbw0_DEVL
oracle 1387   1  0  Mar 25  ?     0:17 ora_dbw0_orcl
oracle 2576   1  1 07:00:03 ?     0:06 ora_dbw0_SEED
oracle 3351 3336 1 17:19:02 ttyp2 0:00 grep dbw0

Notice the process names. The first part is always “ora.” The second part identifies the specific Oracle process, dbw0, lgwr, and so on. The third part is the SID , which identifies the instance. This naming convention enables you to have multiple instances, or databases, on one computer. To see a list of all processes running for an instance, just grep for the SID. For example:

$ ps -ef | grep DEVL
  oracle  2592   1  0 07:00:05 ?  0:00 ora_smon_DEVL
  oracle  2590   1  0 07:00:05 ?  0:03 ora_lgwr_DEVL
  oracle  2588   1  0 07:00:05 ?  0:05 ora_dbw0_DEVL
  oracle  2586   1  0 07:00:05 ?  0:03 ora_pmon_DEVL
  oracle  2594   1  0 07:00:05 ?  0:00 ora_reco_DEVL
  oracle  2597   1  0 07:00:05 ?  0:03 ora_arc0_DEVL

If you want to see all the Oracle processes period, you can grep for the first part of the name: “ora.”