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  • Increasing the maximum I/O size in Linux

    This post is really a quick note to myself to remind me how to bump up the maximum IO size on Linux. I have been benchmarking a bit lately and increasing the maximum size of an I/O request from 512kb to 1024kb looked like something worth doing. Especially since it’s also done in Exadata :)…

  • Troubleshooting high load average on Linux

    This morning I was quite surprised to see one of my lab servers suffering from a high load average. To be fair I haven’t looked at it for a while, it’s just one of these demo systems ticking along … However this was an interesting case! High load averages are usually first felt when you…

  • An introduction to Policy Managed Databases in 11.2 RAC

    I just realised this week that I haven’t really detailed anything about policy managed RAC databases. I remembered having done some research about server pools way back when 11.2.0.1 came out. I promised to spend some time looking at the new type of database that comes with server pools: policy managed databases but somehow didn’t…

  • I’m speaking at Enkitec Extreme Exadata Expo E4

    Just a short notice to those interested that I’m very proud to be in the lineup for Enkitec’s Extreme Exadata Expo. The event takes place August 5-6, 2013 and is held in the Four Seasons Resort & Spa, Irving, Texas. There is plenty of time for you to register. I was really sorry I missed…

  • Linux large pages and non-uniform memory distribution

    In my last post about large pages in 11.2.0.3 I promised a little more background information on how large pages and NUMA are related. Background and some history about processor architecture For quite some time now the CPUs you get from AMD and Intel both are NUMA, or better: cache coherent NUMA CPUs. They all…

  • More on use_large_pages in Linux and 11.2.0.3

    Large Pages in Linux are a really interesting topic for me as I really like Linux and trying to understand how it works. Large pages can be very beneficial for systems with large SGAs and even more so for those with large SGA and lots of user sessions connected. I have previously written about the benefits…

  • 4k sector size and Grid Infrastructure 11.2 installation gotcha

    Some days are just too good to be true :) I ran into an interesting problem trying to install 11.2.0.3.0 Grid Infrastructure for a two node cluster. The storage was presented via iSCSI which turned out to be a blessing and inspiration for this blog post. So far I haven’t found out yet how to…

  • Grid Infrastructure And Database High Availability Deep Dive Seminars 2013

    So this is a little bit of a plug for myself and Enkitec but I’m running my Grid Infrastructure And Database High Availability Deep Dive Seminars again for Oracle University. This time these events are online, so no need to come to a classroom at all. Here is the short description of the course: Providing a…

  • Limiting the Degree of Parallelism via Resource Manager and a gotcha

    This might be something very obvious for the reader but I had an interesting revelation recently when implementing parallel_degree_limit_p1 in a resource consumer group. My aim was to prevent users mapped to a resource consumer group from executing any query in parallel. The environment is fictional, but let’s assume that it is possible that maintenance operations for…

  • OUGN Spring Seminar 2013

    The annual conference held by the Oracle User Group in Norway has once again been just great. It was the second year I went and I have to admit that it was every bit as good as last year, and that’s holding a very high standard. The combination of such great hosts, great speakers and…