Tag Archives: disable

linux

Disable Linux Firewall

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When preparing your RHEL server for an Oracle RDBMS or other application software installations, it is normally a good idea to temporarily disable the OS layer firewall to prevent possible communication errors. This can be performed with the command CHKCONFIG. Use the following procedures to check and disable or enable the RHEL firewall.

1. Logon as the root user.
Using username “root”.
Last login: Mon Jun 2 08:57:14 2014 from 192.168.10.1
[root@linuxpc ~]#
2. Check the current status of RHEL firewall with command ‘SERVICE’ command.
[root@linuxpc ~]# service iptables status
Table: filter
Chain INPUT (policy ACCEPT)
num target prot opt source destination
1 ACCEPT all — 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
2 ACCEPT icmp — 0.0.0.0/0 0.0.0.0/0
3 ACCEPT all — 0.0.0.0/0 0.0.0.0/0
4 ACCEPT tcp — 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:22
5 REJECT all — 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited

Chain FORWARD (policy ACCEPT)
num target prot opt source destination
1 REJECT all — 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited

Chain OUTPUT (policy ACCEPT)
num target prot opt source destination

[root@linuxpc ~]#

3. As shown above the firewall is currently active, You can disable now with the ‘SERVICE’ command.
[root@linuxpc ~]# service iptables stop
iptables: Flushing firewall rules: [ OK ]
iptables: Setting chains to policy ACCEPT: filter [ OK ]
iptables: Unloading modules: [ OK ]
[root@linuxpc ~]#

4. Or you can use the ‘CHKCONFIG’ command to disable the RHEL firewall, which shuts the firewall down on reboot. This is done by adding references to the appropriate /etc/rc.d directory to either kill the service or start the service at given run level.
[root@linuxpc ~]# chkconfig iptables off
[root@linuxpc ~]#

Larry Catt, OCP

linux, Oracle

Disabling SELinux before Oracle installation

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SELinux (Security-Enhanced Linux) provides for additional OS layer security with a default installation. However, this added security can cause issues for installation of multiple software packages of which Oracle is one. This article shows how to disable SELinux before Oracle installation.

1. Logon to your server as root.
2. Open the file /etc/selinux/config with vi.

[root@mylinux /]# vi /etc/selinux/config
# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
# enforcing – SELinux security policy is enforced.
# permissive – SELinux prints warnings instead of enforcing.
# disabled – SELinux is fully disabled.
SELINUX=permissive
# SELINUXTYPE= type of policy in use. Possible values are:
# targeted – Only targeted network daemons are protected.
# strict – Full SELinux protection.
SELINUXTYPE=targeted
~

3. Disable SELinux by changing the option SELINUX to disabled.

SELINUX=disabled

4. Reboot your Linux server for the changes to take affect.

5. This completes disabling of SELinux before Oracle installation.

Larry J. Catt, OCP 9i, 10g
oracle@allcompute.com
www.allcompute.com

Oracle 10g, RAC, unix

Disabling Oracle RDBMS RAC features

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The determination of Oracle binary support for Real Application Clustering is made during installation on all supported platforms. Thus an installation made for a RAC database install will result in errors for single database instances. However, you can modify the binaries to support single instance database features after installation. This article details the steps to modify your Oracle binaries to support Oracle single instance database.

1. Logon to your Oracle database server as the Oracle software owner.

2. Change directory to your ORACLE_HOME/rdbms/lib.

cd $ORACLE_HOME/rdbms/lib

3. Use make to recreate your Oracle binaries with the option rac_off

make -f ins_rdbms.mk rac_off

4. Change directory to your ORACLE_HOME/bin.

5. Execute the utility relink with option all, to recreate all binary files.

relink all

6. This completes altering your Oracle RDBMS binaries to support Oracle RAC features.

Larry J. Catt, OCP 9i, 10g
oracle@allcompute.com
www.allcompute.com

11g, Oracle, Oracle 10g, oracle 9i

Stop Tracing on Oracle Listener:

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Most Oracle database connects are made through the use of an Oracle process called the LISTENER which monitors a certain machine and port for connection requests to one or more database instances. There are times when a DBA or SA will want to monitor connects being made through the listener for various reasons. However, tracing the Oracle LISTENER process at the user, admin, or support level can consume large amounts of disk space; thus it should only be performed on a temporary basis. This article covers stopping of a listener trace at any the three levels and will work on UNIX, Linux, and Windows based machines.

1. Logon to your Oracle database server as the Oracle software owner.

2. Open up the LSNRCTL utility.

mylinux:>lsnrctl

LSNRCTL for LINUX: Version 10.2.0.4.0 – Production on 04-FEB-2010 19:17:05

Copyright (c) 1991, 2007, Oracle. All rights reserved.

Welcome to LSNRCTL, type “help” for information.

LSNRCTL>

3. If you are not using the default name of the Oracle listener (LISTENER) then define the Oracle listener name with the following command: set current_listener {listener_name}

LSNRCTL> set current_listener listener_orcl
Current Listener is listener_orcl
LSNRCTL>

4. If you have established a password for your oracle listener set it in the LSNRCTL session with the following command: set password {listener_password}

LSNRCTL> set password oracle
The command completed successfully
LSNRCTL>

5. Turn off tracing by specifying 0 or off as the level with the following command: set trc_level {level}

LSNRCTL> set trc_level 0
Connecting to
(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.0.110)(PORT=1521)))
listener_orcl parameter “trc_level” set to off
The command completed successfully
LSNRCTL>

or

LSNRCTL> set trc_level off
Connecting to
(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.0.110)(PORT=1521)))
listener_orcl parameter “trc_level” set to off
The command completed successfully
LSNRCTL>

7. Save the changes made to the listener.ora file with the following command: save_config

LSNRCTL> save_config
Connecting to
(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.0.110)(PORT=1521)))
Saved listener_orcl configuration parameters.
Listener Parameter File /opt/app/oracle/10.2.0/network/admin/listener.ora
Old Parameter File /opt/app/oracle/10.2.0/network/admin/listener.bak
The command completed successfully
LSNRCTL>

8. This completes disabling of the Oracle Listener tracing process.

Larry J. Catt, OCP 91, 10g
oracle@allcompute.com
www.allcompute.com

Oracle, Oracle 10g, oracle 9i, SQL

Disabling and Enabling Oracle Jobs with DBMS_JOB

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Oracle provides the ability to schedule predetermined jobs via the package DBMS_JOB, just as you would in a UNIX environment with CRON or the Windows environment with SCHEDULER. Normally, a production database will have several dozen pre-scheduled jobs executing at various times of the day. There are times when you will need to disable a JOB or all jobs due to various events. This article explains the use of procedure DBMS_JOB.BROKEN which allows you to disable a job and re-enable it once you are finished. This procedure will work in Oracle 8, 8i, 9i, 10g, and 11g.

NOTE: only the user whom own a job can modify with the package DBMS_JOB, if you logon to the database as an administrator and want to disable jobs you must use the package DBMS_IJOB.

1. Logon to SQL*PLUS as sysdba

Mylinux> sqlplus ‘/ as sysdba’

SQL*Plus: Release 10.2.0.3.0 – Production on Tue May 25 10:19:38 2009

Copyright (c) 1982, 2006, Oracle. All Rights Reserved.

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 – Production
With the Partitioning, Real Application Clusters, OLAP and Data Mining options

SQL>

2. To disable all jobs on the system use the following SQL statement to generate your SQL:
“select ‘exec dbms_ijob.broken(‘||job||’,true);’ from dba_jobs;”

SQL> select ‘exec dbms_ijob.broken(‘||job||’,true);’ from dba_jobs;

‘EXECDBMS_IJOB.BROKEN(‘||JOB||’,TRUE);’
———————————————————————
exec dbms_ijob.broken(1,true);
exec dbms_ijob.broken(2,true);
exec dbms_ijob.broken(4,true);
exec dbms_ijob.broken(5,true);
exec dbms_ijob.broken(41,true);
exec dbms_ijob.broken(42,true);
exec dbms_ijob.broken(370,true);
exec dbms_ijob.broken(371,true);
exec dbms_ijob.broken(1605,true);
exec dbms_ijob.broken(2204,true);
exec dbms_ijob.broken(2224,true);
exec dbms_ijob.broken(2225,true);
exec dbms_ijob.broken(2245,true);

13 rows selected.

SQL>

3. Execute the SQL generated by the step above to disable all jobs.

exec dbms_ijob.broken(2224,true);
exec dbms_ijob.broken(2225,true);
exec dbms_ijob.broken(2245,true);
PL/SQL procedure successfully completed.

SQL>
PL/SQL procedure successfully completed.

SQL>
PL/SQL procedure successfully completed.
…
…
…

4. To re-enable all jobs on the system use the following SQL statement to generate your SQL:
“select ‘exec dbms_ijob.broken(‘||job||’,false);’ from dba_jobs;”

SQL> select ‘exec dbms_ijob.broken(‘||job||’,false);’ from dba_jobs;

‘EXECDBMS_IJOB.BROKEN(‘||JOB||’,FALSE);’
———————————————————————-
exec dbms_ijob.broken(1,false);
exec dbms_ijob.broken(2,false);
exec dbms_ijob.broken(4,false);
exec dbms_ijob.broken(5,false);
exec dbms_ijob.broken(41,false);
exec dbms_ijob.broken(42,false);
exec dbms_ijob.broken(370,false);
exec dbms_ijob.broken(371,false);
exec dbms_ijob.broken(1605,false);
exec dbms_ijob.broken(2204,false);
exec dbms_ijob.broken(2224,false);
exec dbms_ijob.broken(2225,false);
exec dbms_ijob.broken(2245,false);

5. Execute the SQL generated by the step above to enable all jobs.

exec dbms_ijob.broken(370,false);
exec dbms_ijob.broken(371,false);
exec dbms_ijob.broken(1605,false);
exec dbms_ijob.broken(2204,false);
SQL>
PL/SQL procedure successfully completed.

SQL>
PL/SQL procedure successfully completed.

SQL>
PL/SQL procedure successfully completed.

6. This completes the disablement and enablement of jobs with DBMS_JOB package.

Larry J Catt, OCP 9i, 10g
oracle@allcompute.com
www.allcompute.com

11g, Oracle, Oracle 10g

Disabling and Enabling Oracle job with DBMS_SCHEDULER.

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Oracle 10g and higher provides the DBMS_SCHEDULER package to create pre-defined jobs for execution, like executing schedule jobs in UNIX with CRON and in Windows with the SCHEDULER. There are times during maintenance when you need to disable scheduled jobs from executing in order to perform other tasks. The disabling of scheduled jobs is performed by the procedure DBMS_SCHEDULER.DISABLE. In this article we will review the use of DBMS_SCHEDULER in disabling and re-enabling pre-defined Oracle jobs. This procedure will work in Oracle 10g and 11g.

1. Connect to SQL*PLUS as sysdba.

Mylinux:>sqlplus ‘/ as sysdba’

SQL*Plus: Release 10.2.0.4.0 – Production on Tue Apr 21 13:05:00 2009

Copyright (c) 1982, 2007, Oracle. All Rights Reserved.

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 – 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL>

2. Execute the following SQL to build the statements to disable the jobs:
“select ‘exec bms_scheduler.disable(name=>’||””||JOB_NAME||””||’);’ from dba_scheduler_jobs;”

SQL> select ‘exec dbms_scheduler.disable(name=>’||””||JOB_NAME||””||’);’
from dba_scheduler_jobs;

‘EXECDBMS_SCHEDULER.DISABLE(NAME=>’||””||JOB_NAME||””||’);’
——————————————————————–
exec dbms_scheduler.disable(name=>’PURGE_LOG’);
exec dbms_scheduler.disable(name=>’FGR$AUTOPURGE_JOB’);
exec dbms_scheduler.disable(name=>’GATHER_STATS_JOB’);
exec dbms_scheduler.disable(name=>’AUTO_SPACE_ADVISOR_JOB’);
exec dbms_scheduler.disable(name=>’MGMT_CONFIG_JOB’);
exec dbms_scheduler.disable(name=>’MGMT_STATS_CONFIG_JOB’);
exec dbms_scheduler.disable(name=>’PERSTAT_SNAP’);

7 rows selected.

SQL>

3. Take the output from the previous step and execute it.

SQL> exec dbms_scheduler.disable(name=>’PURGE_LOG’);
exec dbms_scheduler.disable(name=>’FGR$AUTOPURGE_JOB’);
exec dbms_scheduler.disable(name=>’GATHER_STATS_JOB’);

PL/SQL procedure successfully completed.

SQL>
PL/SQL procedure successfully completed.

SQL>
PL/SQL procedure successfully completed.

SQL>

4. Execute the following SQL to build the statements to re-enable the jobs.
“select ‘exec dbms_scheduler.enable(name=>’||””||JOB_NAME||””||’);’ from dba_scheduler_jobs;”

SQL> select ‘exec dbms_scheduler.enable(name=>’||””||JOB_NAME||””
dba_scheduler_jobs;

‘EXECDBMS_SCHEDULER.ENABLE(NAME=>’||””||JOB_NAME||””||’);’
——————————————————————-
exec dbms_scheduler.enable(name=>’PURGE_LOG’);
exec dbms_scheduler.enable(name=>’FGR$AUTOPURGE_JOB’);
exec dbms_scheduler.enable(name=>’GATHER_STATS_JOB’);
exec dbms_scheduler.enable(name=>’AUTO_SPACE_ADVISOR_JOB’);
exec dbms_scheduler.enable(name=>’MGMT_CONFIG_JOB’);
exec dbms_scheduler.enable(name=>’MGMT_STATS_CONFIG_JOB’);
exec dbms_scheduler.enable(name=>’PERSTAT_SNAP’);

7 rows selected.

SQL>

5. Take the output from the previous step to re-enable jobs.

SQL> exec dbms_scheduler.enable(name=>’PURGE_LOG’);
exec dbms_scheduler.enable(name=>’FGR$AUTOPURGE_JOB’);
exec dbms_scheduler.enable(name=>’GATHER_STATS_JOB’);
exec dbms_scheduler.enable(name=>’AUTO_SPACE_ADVISOR_JOB’);
exec dbms_scheduler.enable(name=>’MGMT_CONFIG_JOB’);
exec dbms_scheduler.enable(name=>’MGMT_STATS_CONFIG_JOB’);
exec dbms_scheduler.enable(name=>’PERSTAT_SNAP’);

PL/SQL procedure successfully completed.

SQL>
PL/SQL procedure successfully completed.

SQL>
PL/SQL procedure successfully completed.
…
…
…

That completes disabling and enabling jobs with DBMS_SCHEDULER in 10g and 11g.

Larry J Catt, OCP 9i, 10g
oracle@allcompute.com
www.allcompute.com