Steps to install oracle on Linux

As per Oracle Flexible Architecture(OFA) oracle recommends us the following

1.create oinstall & dba groups

2.create oracle base

3.create oracle home

note: oracle base is not mandatory, if we are planning to install multiple versions of oracle in the

same server, recommended to have oracle base.

                >groupadd oinstall

                >groupadd dba

                or

                >groupadd -g 500 oinstall

                >groupadd -g 501 dba

500 & 501 are group id's

2.create the directory structure for oracle base and oracle home.

                >mkdir -p /u01/app/oracle/product  -->oracle base

                >mkdir -p /u01/app/oracle/product/11.2.0/db_home -->11g home

3.changing ownership & setting proper permissions on directory structures.

4.configure kernal parameters as per installation docuement.

note : In OEL(Oracle Enterprise Linux) its not necessary to set, but in other flavours of OS, we need

to set the parameters as per installation docuements.

kernal.Shmmax : This parameter represents the size in bytes of a single shared memory segment.Oracle recommends to set as much as possible to accomidate the entire SGA in a single shared memory segment.

Memory is allocated to SGA in the form of granules(4mb,16mb).

Inadequate value for this parameter leads to error message "Unable to attach shared memory segment" during database creation.

kernal.Shmmni : This parameter represents the total number of shared memory segments system wide(default value 4096).For most of the environments/configurations, default value is sufficient.

kernal.sem : This is related to semaphores. Semaphore is a locking mechanism at OS level.

kernal.File-max : This parameter represents the maximum number of data files supported by oracle

(upto oracle 10g, 65536 and in oracle 11g, almost 6lacs).

kernal.net.ipv4.ip_local_port_range : represents the range of ports that can be used.

eg: default listener port is 1521.

5.set shell limits for oracle user(optional)

                >vi /etc/security/limits.conf

                                oracle soft nproc <value>

                                oracle hard nproc <value>

                                oracle soft nofile <value>

                                oracle hard nofile <value>

6.invoke runInstaller

7.configure .bash_profile ( . indicates hidden).

NOTE : block size in oracle9i is 2k whereas block size in oracle10g & 11g is 8k.