Posts

Showing posts from July, 2011

Change Oracle EnterPrise manager

DBA who never heard in this product from oracle ?

Some times for security issue we need to change the password , but as we all know nothing goes easy but all you have to do follow the below steps :


Stop Oracle Enterprise Manager emctl stop dbconsole
emctl status dbconsole Connect to database as sysdba and change system password sqlplus / as sysdba

alter user sys identified by NewPassword ;
alter user system identified by NewPassword ;
alter user dbsnmp identified by NewPassword ;
alter user sysman identified by NewPassword ;
after this emctl set password and put your newpassword restart your enterprise maybe you will not need to the below steps .
cd $ORACLE_HOME/sysman/config/emoms.properties : oracle.sysman.eml.mntr.emdRepUser=SYSMAN
oracle.sysman.eml.mntr.emdRepPwd=d0355495a68cd5ae
oracle.sysman.eml.mntr.emdRepPwdEncrypted=TRUE TO oracle.sysman.eml.mntr.emdRepUser=SYSMAN
oracle.sysman.eml.mntr.emdRepPwd=Newpassword
oracle.sysman.eml.mntr.emdRepPwdEncrypted=FALSE "in some database ver…

Auditing Vs Performance on Oracle Database

Image
You show this (part of a) AWR report to the DBA and he proudly concludes: disable auditing, it is killing the performance! And thus, quite often Oracle database auditing is not enabled. And here are the 3 main reasons why auditing is not turned on:- DBAs, developers, etc. are not familiar with this feature: For those who are not familiar with auditing. - Security is not considered important and necessary: For those who do not consider auditing important, I wish them luck. They are anyway not interested in what I have to say..
- Performance is being hit by enabling auditing: For the ones having issues with performance when auditing is enabled, here is something.There are 3 major reasons why performance suffers when auditing is enabled: too much is being audited, AUD$ still hangs in the SYSTEM tablespace and surprise, surprise: the Oracle bugs.1. Too much is being audited. If it is a new database, spend some time with all parties involved on what to audit. The reality however …

Oracle Database Block corruption

Oracle Database Block corruption

“Block corruption is rare but it does happen. As databases get larger and larger – the probability of it happening at some point nears 100%.”--Mr. Tom Kyte Oracle Expert

Block corruption is while the data is being written to the data blocks, if the write to the block fails abruptly, I mean that there is a partial write in the block, may be because of power disruption or I/O problem, leaving no time for header to be updated, or row data to be populated, oracle leaves the block corrupt.In case of block corruption you can normally use the database unless you try to read that particular block, against which it shoots up the block corruption error.Generally block corruption occurs if write fails on the block, when the transaction is being committed


ORA-01578:
ORACLE data block corrupted (file # string, block # string)
Whenever we encounter above error message mean we have BLOCK CORRUPTION.

NOTE: We can find detail information about block corruption in …

crsctl status resource -t -init in 11.2.0.2 grid infrastructure

11.2.0 grid infrastructure crsctl stat res :

Follow this link please maybe it will be useful for you

11.2.0.2 grid infrastructure

crsctl start crs does not work in 10gR2

How to start crs in oracle 10g , its simple first we need to check if its really exists or not :

1-./crsctl start crs
Attempting to start CRS stack
The CRS stack will be started shortly

2-./crsctl check crs

Failure 1 contacting CSS daemon
Cannot communicate with CRS
Cannot communicate with EVM

3-./srvctl status nodeapps -n

PRKH-1010 : Unable to communicate with CRS services.
[Communications Error(Native: prsr_initCLSS:[3])]


4- ./srvctl start nodeapps -n

PRKH-1010 : Unable to communicate with CRS services.
[Communications Error(Native: prsr_initCLSS:[3])]

5- ./srvctl status nodeapps -n

PRKH-1010 : Unable to communicate with CRS services.
[Communications Error(Native: prsr_initCLSS:[3])]

6- ./crsctl check crs

Failure 1 contacting CSS daemon
Cannot communicate with CRS
Cannot communicate with EVM

--------------------------------------------------------------
if you see the crs is still not working (start) so what is the solution if "srvctl" not working .

What can i do ????
its so simple just o…

Steps To Shutdown/Start Oracle RAC

Hi Again


I will mention steps to shutdown Oracle Real Application Cluster First :
You need to shutdown all the services like the following :

On Linux :
**Change to $ORACLE_HOME/crs/bin

shutdown emctl stop dbconsole .

1- ./srvctl stop database -d .

To check database name :

select DB_name from v$database ;

2-./srvctl stop asm -n

To check node name :
Hostname on terminal .

3-./srvctl stop nodeapps

4-./crsctl stop -all

these steps to stop RAC services on linux :

Windows :

** change to $ORACLE_HOME/crs/bin
1-srvctl.exe stop database -d
2-srvctl.exe stop asm -n
3-srvctl stop nodeapps
4-crsctl.exe stop -all .



Startup RAC services :

1-./srvctl start nodeapps
2-./srvctl start asm -n .
3-./srvctl start database -a .
4-./crsctl start -all .

emctl start dbconsole .

windows the same but without "./" just srvctl.exe
REAL APPLICATION CLUSTER .

You want to build Your Own oracle Rac, but you don't have that much resource and pc's , according the Oracle Rac Requirements its consume lot of money , but if you want to try you to build it
Follow this link please ita maybe will be useful for you all you need is :


Oracle 11g (11.1.0.6) Database & Clusterware SoftwareOracle Enterprise Linux 4 (Update 5)VMware Server 1.0.3

And Follow the steps in the link below

Thank you For your support .
Osama Mustafa

So you want to play with Oracle 11g’s RAC? Here’s how