How to start multiple Oracle database instances and modify memory in Linux

Because of work requirements, you need to install another Oracle instance in a Linux operating system. After receiving help from many netizens, I finally solved the following problem 1: Installing new instances using Linux

Because of work requirements, you need to install another Oracle instance in a Linux operating system. After receiving help from many netizens, I finally solved the following problem 1: Installing new instances using Linux

Because of work requirements, you need to install another Oracle instance in a Linux operating system.

After receiving help from many netizens, I finally solved the following problems:

1. install a new instance
Log On with the Linux Account Oracle, find the dbca under the bin directory, and then create it. Pfile (init. ora) is enabled by default.

2. Solve the Problem of starting multiple instances.
Restart later, so:
Use Oracle remote login (telnet) and then execute
Export Oracle_SID = SID2
Sqlplus/nolog
Conn/as sysdba
Startup

3. Modify SGA
First, you need to modify the Startup Mode:
Create spfile = '/Oracle/SPFILESID2.ORA' from pfile;
SHUTDOWN IMMEDIATE
STARTUP
Alter system set SGA_MAX_SIZE = 3072 m scope = SPFILE (scope = memory | spfile | both)
SHUTDOWN IMMEDIATE
STARTUP
Alter system set SGA_TARGET = 3072 M