Red Hat ENTERPRISE LINUX 5.1 - LINUX ORACLE Tuning Manual page 59

Allowing the Oracle User to Change the Mapped Base Address for Shared Libraries
Allow the oracle user to execute /usr/local/bin/ChangeMappedBase via sudo without
password:
# echo "oracle ALL=NOPASSWD: /usr/local/bin/ChangeMappedBase" >> \
/etc/sudoers
Now the Oracle user can run /usr/local/bin/ChangeMappedBase to change the mapped_base
for its own shell:
$ su - oracle
$ cat /proc/$$/mapped_base; echo
1073741824
$ sudo /usr/local/bin/ChangeMappedBase
$ cat /proc/$$/mapped_base; echo
268435456$
To change the mapping for shared libraries automatically during the Oracle log in process, execute:
# echo "sudo /usr/local/bin/ChangeMappedBase" >> ~/.bash_profile
Now log in as oracle:
$ ssh oracle@localhost
oracle@localhost's password:
Last login: Sun Jan
$ cat /proc/$$/mapped_base; echo
268435456$
Note
If the mapped base address for shared libraries for the Oracle processes was changed,
then every Linux shell that spawns Oracle processes (for example, listener, sqlplus,
etc.) must have the same mapped base address as well. If you execute sqlplus to
connect to the local database, then you will get the following error message, seen in the
screen below, if the mapped_base for this shell is not the same as for the running Oracle
processes.
SQL> connect scott/tiger
ERROR:
ORA-01034: ORACLE not available
ORA-27102: out of memory
Linux Error: 12: Cannot allocate memory
Additional information: 1
Additional information: 491524
SQL>
7 13:59:22 2003 from localhost
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