Showing posts with label RAC. Show all posts
Showing posts with label RAC. Show all posts

Monday, December 5, 2016

RAC: ORA-01410: invalid ROWID

Can try flushing the cache:
alter system flush buffer_cache;

Monday, September 28, 2015

Session hang because 'gc cr request' and 'cr request retry'

In 11g Rac, during datapump import, session hangs at step of importing indexes or constraints.

If you check v$session_wait for the sid, you may notice  'gc cr request' and 'cr request retry':

SQL> select event from v$session_wait where sid=405;

gc cr request

SQL> select event from v$session_wait where sid=405;

cr request retry

Mostly it's caused by Redo log IO performance or the interconnect performance.

You can try:
1) Improve the interconnect performance.
2) Improve the Redo log I/o performance.
3) Set undersore parameter "_cr_server_log_flush" =false.

Wednesday, July 4, 2012

11gR2 Rac install on Centos 6.2 without Oracle ASMLib

Oracle ASMlib is available for linux prior to OL6 or RedHat 6. However, starting from 6, you can only use asmlib for UEK kernel.
On Linux, the built in udev is definitely a better solution to handle persistent device naming and permissions.

Without ASMLib, you don't need to worry about the raw disks everytime when there's a kernel update.

Tuesday, June 19, 2012

What are cvutrace.log.* files

 I was looking to clear some space recently and ran across a 21G directory (<grid_infrastructure_home>/cv/log). Inside there were a lot of files like “cvutrace.log.0_20100720015347″. These files are log files related to a RAC installation. They can safely be deleted.

To stop the files from being generated is add the following at the top of the cluvfy script in the <grid_infrastructure_home>/bin directory.

set SRVM_TRACE=false

export  SRVM_TRACE=false

Friday, April 27, 2012


In Oracle database version 9i there is no way to determine the IP address through a database view. The only way to determine this IP address is with the oradebug command (Please keep in mind oradebug is not a supported product from Oracle, so if there are problems/crashes you are on your own). The oradebug ipc command creates a trace file. The example shows the process:
 SQL> oradebug setmypid
  SQL> oradebug ipc
  SQL> oradebug tracefile_name
The last command will show the name of the created trace file. The next step is opening the trace file and looking for the string SKGXPCTX. The following is a typical example.

SKGXPCTX: 0xcd1e730 ctx
 admno 0x7a0be402 admport:
 SSKGXPT 0xcd1e884 flags SSKGXPT_READPENDING     info for network 0
         socket no 8     IP         UDP 9152
         info for network 1
The cluster interconnect IP address is shown in bold. In the example above
it is

Modify the attribute AUTO_START to “always”

With Oracle 11.2 database auto start policy in the clusterware is restore, which means that clusterware will remember the last state of the database.  If the database was stopped normally then on the next restart of clusterware it won’t be started. Otherwise if the server crashes or by some reason the OS is rebooted then clusterware will start the database because last state was ONLINE (running).

Monday, April 16, 2012

Resize Redo log for RAC

In RAC, you have seperate log groups for each instance (called threads). You can see which group belongs to which thread by querying v$log. When you add new loggroups, you specify which thread it should belong to. The syntax is

ALTER DATABASE ADD LOGFILE THREAD 1 GROUP 5 ('firstlocation','secondlocation') SIZE 1280M;
Enable/Disable Archive logs in a RAC environment

on node 1:
set oracle_sid=racdb1
sqlplus / as sysdba
alter system set cluster_database=false scope=spfile sid='racdb2';


Friday, March 9, 2012

Drop asm disk after moving ocr


Oracle 11gR2 RAC on Windows 2008 using VMWARE

Oracle 11gR2 RAC on Windows 2008 R2 using VMWARE
Network Configuration

Name the network connection as “public” and “private”

Amend the C:\windows\system32\drivers\etc\hosts file to contain the following information.       localhost.localdomain   localhost
# Public   rac1.localdomain        rac1   rac2.localdomain        rac2
#Private   rac1-priv.localdomain   rac1-priv   rac2-priv.localdomain   rac2-priv
#Virtual   rac1-vip.localdomain    rac1-vip   rac2-vip.localdomain    rac2-vip
# SCAN   rac-scan.localdomain rac-scan

Addition changes:First, ensure the public interface is first in the bind order:

How to find Cluster name on RAC instance

Soemtimes you need to check your cluster name on your RAC  instance. Here is the steps:

Adding and removing disks in ASM

Adding and removing disks in ASM

A first for me. I had seen asm in the past but never had hands on experience with it. A client needed some disks moved from 1 diskgroup to the other and so started my journey into ASM. :)