Archive for the ‘Oracle9i’ Category

ORA-00202: controlfile: ‘C:\ORACLE\ORADATA\ORACLE91\CONTROL02.CTL’

ORA-27091: skgfqio: unable to queue I/O

ORA-27070: skgfdisp: async read/write failed

OSD-04006: ReadFile() failure, unable to read from file

O/S-Error: (OS 23) Data error (cyclic redundancy check).

i find this problem on one of my server database. this problem will make oracle fail to mount and open. if you try to connect via sqlplus, you will get error message : Oracle is on initialization startup/shutdown. so you can not enter the database.

below is the step that i do, to resolve the problem.(oracle ver 9i and higher)

1. connect to database using sqlplus with SYS as SYSDBA

2. shutdown immediate the database.

3. create a backup copy of all control file(usually consist of 3 control file with extension CTL) on folder ORADATA\

4. rename CONTROL02.CTL (corrupt control file) to CONTROL02.bak

5. rename one of working control file to become CONTROL02.CTL and then copy this file to folder ORADATA\

6.then startup the database via sqlplus using SYS as SYSDBA

this step only working if one of controlfile is corrupt and need to be replace. and also your controlfile is multiplex. Make sure that the error message is exactly the same with what is written above.


Minh Tran


When exporting data from Oracle DB 9i, encountered by the error:

. exporting pre-schema procedural objects and actions
. exporting foreign function library names for user QLNS
. exporting PUBLIC type synonyms
. exporting private type synonyms
. exporting object type definitions for user QLNS
EXP-00008: ORACLE error 942 encountered
ORA-00942: table or view does not exist
EXP-00024: Export views not installed, please notify your DBA
EXP-00000: Export terminated unsuccessfully


Run catalog.sql,catproc.sql and catexp.sql ( logged in as sys).

Then you should export as normal.


Minh Tran

1. To get currently used character set, issue:

SELECT * FROM nls_database_parameters WHERE parameter LIKE ‘%CHARACTERSET%’.

nls_database_parameters is a view.

2. Check and update, for example, to set nls_characterset = UTF8,nls_nchar_characterset = UTF8, use table props$:



There you go…

Minh Tran

If you want to change the IAS_Admin password, you need to delete the <credentials> line associated with ias_admin in the jazn_data.xml file. However, you would need to shut down the EMWebsite prior to doing this.

.Edit the following file and locate the line that defines the credentials property for use the ias_admin user:


The following example shows the section of jazn-data.xml with the credentials entry in boldface type:


2.Remove the entire line that contains the <credentials> property from jazn-data.xml.

3.Enter the following command from DOS Command window:

%ORACLE_HOME%\bin\emctl set password reset <new password>

The steps outlined in the previous lines work, BUT you have to reboot the machine in order for you to pick up the new password. You can’t simply stop/restart the server, because when you try that, it will ask you for the ias_admin password. But a shutdown/restart will work. Been there and survived!

Actually, you can do an emctl restart since emctl stop asks for the password, but start and restart do not

Be happy administrator

^ ^
Minh Tran