Last day, I was at one training for Oracle installation and service start & shutdown. There I came to know about some Linux commands to start and shutdown an Oracle instance on a Linux machine.
To identify the instance running : The command below will return all Oracle instances which are currently running on that machine.
ps -ef | grep pmon
This command returns following results:
oracle 823 1 0 Dec03 ? 00:00:17 ora_pmon_instance1 oracle 19632 1 0 Nov17 ? 00:06:35 ora_pmon_instance2 oracle 24199 1 0 Nov20 ? 00:05:23 ora_pmon_instance3
instance3 are 3 installations of Oracle on Linux, which are currently running.
My query: So,
ps -ef will only show processes currently running. Suppose,
instance3 is down and you need to start that instance. But, you don't know how many Oracle instances there are on the machine.
How would you get to know that this instance is down?
In Windows, there is a way called services, where you could came to know that these installations are done on Windows for Oracle.