Top 60 Oracle Blogs

Recent comments


Linux takes a page from Solaris… pmap available on Linux.

Recently, there was a thread on an internal alias of old Sun guys.  The problem at hand was to track down a process that is consuming memory on Linux.  This is the type of problem that can be solved many ways (ps, top, etc…), but to my amazement someone mentioned that pmap could be used for Linux…. I guess I didn’t get the memo:)

About 6 months back I wrote a few entries that discussed Solaris tools for the Linux Guy in the posts:

The Oracle Exadata IO Resource Manager Limit Clause, part 2

In my previous post I described how the IO resource manager (IORM) in the exadata storage can be used both to guarantee a minimum amount of IO a database can get (which is what is covered in most material available), but also to set a maximum amount of IO. This is what Oracle calls an inter-database resource manager plan. This is set and configured at the cell level using the cellcli with ‘alter iormplan dbplan’.

Expert Oracle Exadata virtual conference

Today is the last day for getting the early bird’s rate!

Also, our book will be out on Monday!

The Oracle Exadata IO Resource Manager Limit Clause

The Exadata IO Resource Manager (IORM) is a fundamental piece of the exadata database machine since the beginning. The function of the IORM is to guarantee a database and/or category (set via the database resource manager) gets the share of IO as defined in the resource plan at each storage server. The “share” here means the minimal amount of IO. This is widely known and documented in the Exadata documentation. Having a minimal amount of IO means you can guarantee a service level agreement (SLA).

But what if you want to define the maximal amount of IO a database may get? The case of a maximal amount of IO a database can get is that you can use a database on Exadata, and do not (or very limited) change the performance once more databases get onto the same database machine. So instead of having the minimal amount of IO a database must get guaranteed (which is what is documented in the exadata documentation), having a limit on the maximal amount a database can get?

Troubleshooting Oracle Exadata

The crew at My Oracle Support (MOS) [@myoraclesupport] have an excellent starting point for troubleshooting Oracle Exadata. I’d recommend to add this one to your MOS bookmarks.

Oracle Database Machine and Exadata Storage Server Information Center [ID 1306791.1]

Exadata Virtual Conference

I will be participating in an Exadata Virtual Conference which has been organized by Tanel Poder on August 3rd and 4th. This conference will follow the same format as the one Tanel and I did last year with Jonathan Lewis and Cary Millsap. It will be two half days which should provide some flexibility for people with busy schedules. The online format allows all participants to interact directly via chat while the speakers are presenting and then via voice during question and answer sessions. This is a great opportunity to talk to some guys that have done a bunch of work with Exadata. Andy Colvin will be discussing patching which has been problematic for some shops. Andy has done more patching than anyone I know.

The First Exadata Virtual Conference in the World!

We have been secretly planning something with Kerry Osborne – and now it’s official – we will host The First Exadata Virtual Conference in the World, on 3-4 August 2011.

This conference takes place a couple of weeks after our Expert Oracle Exadata book is published (on 18. July – check out the awesome new cover design). So, we thought it’d be a good idea to run this conference, where we can explain some things in a different format, do live demos and answer questions that attendees have.

On the first day Kerry and Randy will talk about some serious fundamentals of Exadata, like how Exadata Smart Scan Offloading works and how to make the IO resource manager work for you (especially important in mixed workload consolidated environments).

And on the second day we’ll dig even deeper, with Andy Colvin talking about how to survive Exadata patching (he has patched more Exadatas than anyone else I know) and me following up with some complex performance troubleshooting stories I’ve encountered recently (trust me – there’s a LOT of issues to troubleshoot ;-)

About the Conference:

Since its release, Oracle Exadata quickly became a hit. Due to the relative “youth” of Exadata technology and internal behavior changes introduced with frequent patch-sets, there’s not much up-to-date quality technical information and know-how available to public. This virtual conference brings you a chance to learn from the leading Exadata experts, from their experience of working with real Exadata environments, from Exadata V1 to the latest X2-8. Additionally, there is plenty of Q&A time scheduled, so you can also get answers to your Exadata-related questions.

The speakers are probably some of the most experienced Exadata consultants in the world, in the field of Exadata deployment, migration, performance, and troubleshooting. Also, Kerry, Randy and Tanel are the authors of the #2970a6; text-decoration: none; padding: 0px; margin: 0px;\" href="">Expert Oracle Exadata book published by Apress in July 2011.


  • 3-4 August 2011


  • Online (or should I say “the Cloud” ;-)


  • 8am – 12pm (PST) on both days – 2 x 1.5h sessions on each day, with Q&A sessions and a break in between


  • Kerry Osborne, Randy Johnson, Andy Colvin from Enkitec
  • Tanel Poder from right here :-)

All of the speakers are hard-core hands-on professionals, having worked on many different real-life (production) Exadata environments of their clients. Enkitec dudes didn’t stop there, they bought a half rack for themselves, just for playing around with it. Yeah (+1 from me), some people buy a red hot Ferrari, some buy a red hot computer rack with an X on it :-)


  • 375 USD (early bird until 22. July), 475 regular price

More information, abstracts and registration:

I don’t think you’ll find an Exadata learning opportunity like this from anywhere else (and any time soon), especially considering the price!

This conference is so hot, that one of the attendees managed to sign up to it even before I had published this page to the world! :-)

Control file inconsistencies during startup when using ASM (ORA-000214)

During some testing I encountered an ORA-000214 during startup of an Oracle database instance:

ORA-00214: control file '+RECO_XXXX/test/controlfile/current.334.755391511'
version 268 inconsistent with file
'+DATA_XXXX/test/controlfile/current.299.755390399' version 265

This is a RAC instance on Exadata, but all techniques in this article will work on any Oracle 11.2.x database using ASM.

This message means the database found two controlfiles which have a different version. If this message appears when the database is open, the database will crash. If an instance is startup after this message, the same error appears, and the database remains in nomount state. Further diagnosis: the control file version in the recovery area is more recent than the version in the data diskgroup (version 268 versus version 265).

For Exadata geeks

Just letting you know that we are all (almost) done with the Expert Oracle Exadata book work and it will be published in less than a month!!!

Expect (many) new blog entries soon! :-)