When you buy an Oracle Database Appliance (ODA) X5-2 off the shelve, you will get a machine with four times 10Gb copper Ethernet (bonded into two interfaces) for public communication and two 40Gb InfiniBand (bonded into one interface) for interconnect communication between the two ODA_BASE’s. You would think that should be more than enough. Well in most cases it is. The interconnect running through InfiniBand is stunning for RAC and the public interface should be (more...)
To build Oracle Clusterware Database at Home, I believe , RAC ATTACK is the best place to learn. Its is a free curriculum and platform for hands-on learning labs related to Oracle RAC. While reviewing the article, I thought to perform 12cR1 RAC installation on OEL 7.2.
Attached is the document :- 12c_RAC_on_OEL7
The attached article is inspired by
Deploying Oracle RAC (more...)
Prompted by comments made by readers about my posts describing how to add a second SCAN in 12c Release 1 and problems regarding the listener_networks parameter I thought it was time to revisit the situation. I’m still running Oracle Linux 7.1/UEK3 (although that should not matter) but upgraded to 22.214.171.124.5. This is the release that is reportedly showing the odd behaviour. I don’t recall my exact version when I wrote (more...)
One of my customer is using Oracle RAC (126.96.36.199) on Windows 2012. This is might not be the most ideal setup I’ve ever seen, but it works and we’ll leave it by that.
One of the side effects of using Oracle RAC on Windows is that some of the basic things I am used to do when using RAC on Linux (for example) is behaving differently when it comes to windows. Here (more...)
On Thursday 21st April, there is a dual UKOUG Database and RAC, Cloud, Infrastructure and Availability special interest group.
For the first time, this even is being held in the fabulous Northern city of Manchester!
There are a dozen interesting, career-assisting, educational talks from end users, Oracle employees and a number of well known Oracle ACE’s at all levels, including Carl Dudley, Jonathan Lewis, Phil Brown and myself.
I will be talking about how (more...)
Over the past years we've worked on many Oracle projects, some with RAC, some without, some which intended to implement RAC and failed, and some which implemented poorly and ripped it out at the last minute.For those new to Oracle, RAC is the Real Application Cluster option for the database which lets you cluster the database servers. The main reason for using for RAC is that it brings resilience to a system, it (more...)
You have a session which is out of control. You decide to kill it. What options are available to you as a DBA?
Assuming you don’t have access to the O/S to be able to use O/S commands to kill the session (using kill -9 in Unix/Linux or orakill in windows to kill the thread within the process – “orakill sid thread”), you probably turn to:
alter system kill session 'sid, serial#, @inst_id' immediate;
By default on an Oracle RAC installation, the listeners are configured to allow any database to register with them. There is no security out of the box to determine which databases may register. While this makes it easy to create new databases without worrying about listener registration, this can cause potential problems in a real environment.
This can be dangerous working with RAC environments where the database registers with both a local and remote listener. The (more...)
If you’ve run an exachk report, y0u may have seen the following message with regard to your databases:
|FAIL||Database Check||Database parameter CLUSTER_INTERCONNECTS is NOT set to the recommended value||db01:dbm011, db02:dbm012||View|
This check is commonly seen when a database is created on Exadata without using the custom “Exadata” templates included with the database creation assistant. These customized templates include a multitude of recommended parameter settings found in (more...)
There are several ways to convert non-RAC database to RAC database:
- using Database Configuration Assistant (DBCA)
- Oracle Enterprise Manager
- rconfig command line utility
In this post I will describe how to perform conversion using rconfig utility.
I noticed something for the first time tonight when I was playing around in the Enkitec lab – something that I have been doing wrong for a while. When working in the lab, I often rely on the crsctl command to shut down the entire cluster stack for me. It’s really easy to use “crsctl stop cluster -all” followed by “dcli -l root -g ~/dbs_group /u01/app/188.8.131.52/grid/bin/crsctl stop crs” to get everything down (more...)
Removing a service via srvctl has not historically resulted in the service being fully removed from the database and it would still be visible in DBA_SERVICES as show below in an 184.108.40.206 database:
Create the service:
$ srvctl add service -d orcl -s demo -r "ORCL1,ORCL2"
Original Post can be viewed at MGMTDB: Grid Infrastructure Management Repository
MGMTDB is new database instance which is used for storing Cluster Health Monitor (CHM) data. In 11g this was being stored in berkley database but starting Oracle database 12c it is configured as Oracle Database Instance. In 11g, .bdb files (more...)
Original Post can be viewed at portmap: unrecognized service on RHEL6
Quick note for people using NFS for shared storage on RAC database. Till RHEL5 we had to ensure nfs,nfslock and portmap service has to be running. These services are required otherwise you will get following errors while mounting database(more...)
[I originally posted this over at the Pythian blog. If you're not following it, you should! Way more content, by far smarter people than lil ol' me.]
After reviewing my blog post about running EBS OVM templates in VirtualBox, two of my teammates suggested that I work on something with potentially broader appeal. Their basic message was, "This is really cool for us EBS nerds, but what about the Core DBAs?"
So how does "11gR2 RAC in an hour" sound? In this post, I'll demonstrate how to deploy the pre-built Oracle VM templates to create a two-node (more...)
A couple of Highlights of this release seem to be
- Enhanced odachk 2.16
- A trace file analyzer
- The ability to now use normal (more...)
Tuning has always being good fun and something like a challenge for me.
From time to time we are being asked to find out why something did run slow while you are sleeping; answering this question is, in most cases, a challenge.
My batch did run slow last night, can you let us know why? Or why did this query run slow? Are questions we, as DBAs, have to answer from time to (more...)