Grid DBA

VirtaThon 2011 is the first Oracle online/virtual conference and is hosted by BrainSurface.com. The conference will feature many well known and respected Oracle experts and speakers and a few unknown ones (including yours truly). This will mark my debut as a public speaker and I am grateful for the opportunity after having only aspirations for some time now. You can sign up and register for VirtaThon here  and the session schedule can be found here .

Here are some steps I used to troubleshoot the failure of a public network used for SCAN in a 2-node RAC cluster. Note: I used an aliased crsstat   for the command: crsctl stat res –t Check the status of the Clusterware resources. You can see that there are several resources that are offline below. The ones highlighted in red are the ones we are interested in. The resource for the local listener is now offline while the VIP has been failed over. You will also notice that all of the SCAN Listeners have been failed over to the surviving node. grid@tibora30[+ASM1]-/u01/11.2.0/grid/log/tibora30 >crsstat -------------------------------------------------------------------------------- NAME           TARGET  STATE        SERVER                   STATE_DETAILS ----------------------------------------------...

There has been a lot of talk in the ubiquitous cloud space recently and more specifically the PaaS service delivery model. Naturally this piqued my curiosity. How does the database fit in the cloud? Just about every major enterprise vendor is jumping on the cloud bandwagon. And rightfully so. Private clouds are now being pushed by Oracle with Exalogic Elastic Cloud and Exadata, IBM with SmartCloud and VMware with Cloud Foundry just to mention a few. Amazon AWS and Rackspace are the major players in the public cloud stratosphere. Add to this community Clouds like OpenStack The easiest to do an evaluation is by using Amazon AWS public cloud services. Amazon AWS provides Relational Database Service (RDS) for MySQL and Oracle Database 11g. Strictly speaking EC2 is a Infrastructure as a Service (IaaS) delivery model. However, the use of AMIs enable PaaS characteristics where complete environments can be easily packaged and deployed in EC2. There are several publicly available Oracle Da...

Ever received this error message in your alert log? I have on a couple of occasions. Perhaps an application server started spawning more database connections than it normally does in turn creating more processes on the database. The Oracle description of this error is: Error: ORA 20 Text: maximum number of processes exceeded   Cause: An operation requested a resource that was unavailable. The maximum number of processes is specified by the initialization parameter PROCESSES. When this maximum is reached, no more requests are processed. Action: Try the operation again in a few minutes. If this message occurs often, shut down Oracle, increase the PROCESSES parameter in the initialization parameter file, and restart Oracle. But what if you cannot connect to your database to shut it down and increase the parameter? oradba01t[labdb01]-/home/oracle/>sqlplus  /as sysdba SQL*Plus: Release 11.1.0.7.0 - Production on Mon Jun 6 11:25:05 2011 Copyright (c) 1982, 2008, Ora...

I don't normally do product reviews, but at the request of my fellow Oracle tweeps (@hillbillytoad) I have attempted to do my first review in this post. Here goes. While working on a project to implement a new enterprise backup software for Oracle (EMC Avamar), I was asked certain questions about the Oracle database backups - how large are the database backups? What is the growth rate of backups? What is the rate of change of databases? How many databases are backed up per hour? How many level 0 and level 1 incremental backups are done over a period of time? It's relatively straightforward to get this information from one or two databases but a little bit more challenging across the enterprise with hundreds of databases. We can query the v$ views in the target databases - v$database, v$backup_set, v$backup_set_details, v$rman_status etc.. or their recovery catalog counterparts rc_database, rc_backup_set, rc_backup_set_details (see summary of RMAN catalog views   here ). Separ...

Having worked on Oracle RAC since 9i, there hasn't been a time when I haven't faced something new or realized something was not what I thought it was. I think this is one of the reasons why I enjoy working on these systems - always a challenge. I stopped my RAC database to put it into noarchivelog mode using the srvctl command [oracle@oradba10t oracle]$ srvctl stop database -d labrac Next I proceeded to connect to the first instance to startup in mount mode [oracle@oradba10t oracle]$ sqlplus /nolog SQL*Plus: Release 10.2.0.4.0 - Production on Thu May 5 09:47:15 2011 Copyright (c) 1982, 2007, Oracle.  All Rights Reserved. SQL> conn / as sysdba Connected to an idle instance. SQL> startup mount ORA-29760: instance_number parameter not specified Wait, what's this? I've never encountered this error message before. Googled a bit and realized that most of the responses were a bit far fetched since the database had been in perfect working order before I stopped...

While installing Oracle RAC it is important to setup SSH user equivalence for installation of of the binaries.  Oracle 11gR2 RAC now includes automatic ssh setup. While reading one of my favorite blogs by Martin Bach  he describes using a utility called sshUserSetup.sh for setting up user equivalence for RAC . This takes out some of the repetitive steps needed to setup ssh user equivalence when installing a RAC cluster.  As Martin pointed out you can also use OUI to setup user equivalence but it helps if you can run the cluster verification utility (CVU) to check on many pre-requisites before starting the installation.  During installation using OUI on the AIX platform however, OUI is unable to perform automatic SSH setup. This means that SSH user equivalence will need to be setup manually prior to installation. To ease the setup all you need to do is to run the sshUserSetup.sh script and follow the prompts directions. It takes as parameters the user (oracle or gr...