This category contains 71 posts

Understanding CPU on AIX Power SMT Systems

This month I worked with a chicagoland company to improve performance for eBusiness Suite on AIX. I’ve worked with databases running on AIX a number of times over the years now. Nevertheless, I got thrown for a loop this week. TLDR: In the end, it came down to a fundamental change in resource accounting that … Continue reading

Patching Time

Just a quick note to point out that the October PSU was just released. The database has a few more vulnerabilities than usual (31), but they are mostly related to Java and the high CVSS score of 9 only applies to people running Oracle on windows. (On other operating systems, the highest score is 6.5.) … Continue reading

Grid/CRS AddNode or runInstaller fails with NullPointerException

Posting this here mostly to archive it, so I can find it later if I ever see this problem again. Today I was repeatedly getting this error while trying to add a node to a cluster: There were two notes on MOS related to NullPointerExceptions from runInstaller (which is used behind the scenes for addNode … Continue reading

OSP: Overview

This is the second of twelve articles in a series called Operationally Scalable Practices.  You can read the introduction in the first article. In short, this series offers helpful suggestions for younger organizations and newer DBAs to best position them for very large-scale growth. Before getting into specifics, we will lay out a general overview … Continue reading

Voting Disk Lies (CRS-4000)

Add this to the category of annoyingly unhelpful error messages. I’m working on a mostly-automated process to create a new cluster by cloning another existing cluster. After running OUI (Oracle Universal Installer – called by config.sh to just run config assistants) there is a single ASM diskgroup which contains both the OCR and Voting Disk; … Continue reading

How To Troubleshoot OEM 12c Cloud Control Auto-Discovery

I was recently involved with an upgrade project to go from to on an Exadata V2. We hit some snags during the upgrade specifically related to OEM 12c Cloud Control. We performed an out-of-place upgrade and OEM had some difficulty in dealing with this. 12c Cloud Control is supposed to run a … Continue reading

Set Up Exadata for Cloud Control

I recently helped setup an Exadata X2-8 Database Machine with the latest version of OEM Cloud Countrol ( A few documents do exist for this process – the most useful of which are the Exadata Discovery Cookbook and the Setup Automation Kit. However I found a few inconsistencies and problems; I think the existing documents … Continue reading

Adaptive Log File Sync: Oracle, Please Don’t Do That Again

The Summary Underscore parameter _use_adaptive_log_file_sync Default value changed in from FALSE to TRUE Dynamic parameter Enables a new method of communication for LGWR to notify foreground processes of commit Old method used semaphores, LGWR had to explicitly “post” every waiting process New method has the FG processes sleep and “poll” to see if commit … Continue reading

Lessons from Africa, Part 2

Last week was busy… making travel arrangements for this week’s trip to New York (technically Jersey) and some light analysis of AWR reports from exadata RAT runs and some heavy troubleshooting of a Solaris x86 RAC cluster with random node reboots. (I think I finally traced the node reboots to a kernel CPU/scheduling problem). I … Continue reading

Lessons From Rural Africa

It has been nine months since I’ve written here. Needless to say, a lot has happened! First, my family was living in Africa for three months earlier this year while I did some tech work at an NGO hospital. Second, upon our return I decided to join the good people at Pythian. I’m not moving … Continue reading


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contact: 312-725-9249 or schneider @ ardentperf.com