Who's online

There are currently 0 users and 36 guests online.

Recent comments


Fixing a problem with the ASM spfile preventing RAC 12c from starting

This is a little note to myself on how to fix a corrupt spfile in clustered ASM. I hope you find it useful, too.

Let’s assume you made a change to the ASM (server) parameter file that causes an issue. You are most likely to notice this once CRS is restarted but parts of the stack fail to come up. If “crsctl check crs” mentions any component not started you can try to find out where in the bootstrap process you are stuck. Here is the output from my system.

IOUG Collaborate 2015

I will be presenting two topics in IOUG Collaborate 2015 in Vegas. Use the show planner and add my presentations to your schedule :)

Session #189: April 13 Monday 9:15 to 10:15AM Topic: Oracle Database 12c In-Memory Internals. Room Palm B

Session #145: April 13 Monday 12:45PM-1:45PM Topic: Tools and Techniques for Advanced Debugging in Solaris & Linux (mostly live demo). Room Palm B.

Cluster Cache Coherency in EM12c

January is winding down and RMOUG Training Days 2015 is just around the corner, taking up much of my after work hours.

With that, we are going to discuss a great performance console in the EM12c cloud control-  Cluster Cache Coherency.

RMOUG Training Days 2015

I will be talking in Rocky Mountain Oracle User Group Training Days 2015(, with live demos (hopefully there will be no failures in the demo). My topics are:

Feb 17: Deep dive: 3:15PM to 5:15PM – RAC 12c optimization: I will discuss RAC global cache layer in detail with a few demos. You probably can’t find these deep Global Cache layer details anywhere else :)

Feb 19: Wednesday: 2:45PM to 3:45PM – Advanced UNIX tools: I will discuss both Solaris and Linux advanced tools to debug deep performance issues.

Feb 19: Wednesday: 12:15PM – 1:15PM – Exadata SIG panel with Alex Fatkulin.

Come to Denver. Come on, it won’t be cold ( I think :) )

Installing Oracle RAC on Oracle Linux 7-part 2

In the first part of the article series you could read how a kickstart file made the installation of Oracle Linux 7 a lot more bearable. In this part of the series it’s all about configuring the operating system. The installation of Grid Infrastructure and the Oracle database is for another set of posts.

There are quite some differences between Oracle Linux 6 and 7

Adventures in RAC: gc buffer busy acquire and release

It seems that I’m getting more and more drawn into the world of performance analysis, and since I sometimes tend to forget things I need to write them down. I almost enjoy the “getting there” more than ultimately solving the problem. You pick up quite a few things on the way.

This environment is Exadata but as with so many things the fact that the database is on Exadata shouldn’t matter.

So here is one of these posts, this time I’m writing up what I saw related to GC Buffer Busy Acquire.

gc buffer busy acquire?

Whenever I see a wait event I haven’t dealt with extensively in the past I try to provoke behaviour to study it more closely. But first you need to know the event’s meaning. One option is to check v$event_name:

OOW14 Session: RAC'fying Multitenant

Thank you for attending my session RAC'fying Multitenant at Oracle Open World 2014. You can download the slide deck here.

[Updated] Oct 4th, 2014: The article on multitenant I wrote for OTN is available here. This article shows various commands I referenced in my session, e.g. point in time recovery of PDBs.

As always I would love to hear from you.

OOW14 Session: Cache Fusion Demystified

Thank you all those who attended my session Cache Fusion Demystified.

As I mentioned, it was impossible to fit in a demo within that compressed 45 minute timeline. I put the details of the demo in a separate file with all the scripts and instructions that allows you to execute the demos at your own site.Download the slide deck as well as the scripts. In addition I have also written a whitepaper to explain the concepts clearer.

Download the slides, the paper, the demo scripts and instructions here.

I sincerely hope it demystified one of the most complex topics in Oracle RAC. As always, I would love to hear from you about your experience.

A first look at RAC 12c (part I)

I have recently upgraded my RAC system to RAC including the RDBMS installation. Currently I am updating my skills with information relevant to what I would normally have called 12c Release 2 (so that would also answer the question: when is 12c Release 2 coming out?). Then I realised I haven’t posted a first look at RAC 12c post yet-so here it comes.

There are a few things that aren’t specifically mentioned in the new features guide that caught my eye. First of all, RAC 12 does a few really cool things. Have a look at the srvctl command output: