Linux User-Group Console

This post shows you how to add the menu option and GUI to set users and groups. It’s quite a bit easier than mastering all the command-line syntax. It makes setting up the required user and group accounts for an Oracle Enterprise or MySQL database solution much easier.

You add the utility by calling the yum (Yellowdog Updater, Modified) utility like this:

yum installed -y system-config_users

You should see the following:

Loaded plugins: langpacks
Usage:  (more...)

Oracle SGA memory allocation on startup

Recently I have been presenting on what running on a large intel based NUMA system looks like (OTN EMEA tour in Düsseldorf and Milan, and I will be presenting about this at the Dutch AMIS 25th anniversary event in june). The investigation of this presentation is done on a SGI UV 300 machine with 24 terabyte of memory, 32 sockets (=NUMA nodes), 480 core’s and 960 threads.

Recently I have been given access to a (more...)

Fix VMware Networking

Occasionally, my students loose their network connection when copying their virtual machines. This article shows you how to rebuild your Internet connection.

The first step requires you to identify the port number on your host operating system, which is typically Windows OS or Mac OS X. You can find that by running the following search from a Mac OS X Terminal session or Windows OS Command session.

If you’re on the Mac OS X, you (more...)

Automatic install of SOA Suite and Service Bus 12cR2.

Lately I worked on a set of scripts to automatically install Weblogic Infrastructure, SOA/BPM Suite, Service Bus, etc. Since I implemented a reworked set yesterday at another customer it might be nice to describe them here.

The scripts help in installing the software and creating the Repository. I started to create a script for creating the domain, but haven't it working yet. A good starting poing would be this blog of Edwin Biemond for the (more...)

Experimenting with the ZFSSA’s snapshot capability using the simulator

Recently I have been asked how the Copy-on-Write cloning works on the ZFS Storage Appliance. More specifically, the question was about the “master” copy: did it have to be static or could it be rolled forward? What better than a test to work out how it works. Unfortunately I don’t have an actual system available to me at home so I had to revert to the simulator, hoping that it represents the real appliance accurately.

(more...)

New Installation Cookbook: Oracle Linux 6.7 with Oracle 11.2.0.4 RAC

cookbookI’ve updated my install cookbooks page to include a new cookbook for installation of Oracle 11.2.0.4 Real Application Clusters on Oracle Linux 6.7.

This is also the first one I’ve published since I left the employment of Violin Memory to work for Kaminario, so this install uses a Kaminario K2 All Flash Array. However, it applies very well to any Oracle RAC installation which uses relatively capable storage.

Enjoy:

https://flashdba.com/install-cookbooks/oracle-linux-6-7-with-oracle-11-2-0-4-rac/


Filed (more...)

SystemTap Guru Mode and Oracle SQL Parsing

Introduction and motivations

SystemTap and dynamic tracing tools in general give administrators great control on their systems with the relatively little additional effort to learn the new tools. In this post you will see of how SystemTap that can be used to modify data on the fly at runtime. The outcome is a form of "live patching". Examples are provided on how to apply these ideas to Oracle SQL parsing functionality. This type of "guru mode" use (more...)

Poll a Microsoft Exchange mailbox from OSB using DavMail

The Oracle Service Bus has built in features to poll an IMAP of POP3 mail account. There are loads of excellent blog posts that exactly describe how to do it. However, when the mail server happens to be a Microsoft Exchange server, things become shady. Exchange’s IMAP implementation tends to be not really that compatible, and the server log will fill up with stacktraces such as:

javax.mail.MessagingException: Connect failed;
  nested exception is:
        java. (more...)

Oracle Linux 7 disks and udev

I was setting up disk devices for ASM in Oracle Linux 7. I knew things have changed between Oracle Linux 6 and Oracle Linux 7, but only just a little bit.

First of all, let’s take a look at the current disk usage. To see what disk devices are visible and how they are used, use lsblk:

# lsblk
NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
fd0           2:0    1    4K  0 disk
sda           8:0    0    (more...)

The Oracle wait interface granularity of measurement

The intention of this blogpost is to show the Oracle wait time granularity and the Oracle database time measurement granularity. One of the reasons for doing this, is the Oracle database switched from using the function gettimeofday() up to version 11.2 to clock_gettime() to measure time.

This switch is understandable, as gettimeofday() is a best guess of the kernel of the wall clock time, while clock_gettime(CLOCK_MONOTONIC,…) is an monotonic increasing timer, which means it (more...)

PL/SQL context switch, part 2

This is the second blogpost on using PL/SQL inside SQL. If you landed on this page and have not read the first part, click this link and read that first. I gotten some reactions on the first article, of which one was: how does this look like with ‘pragma udf’ in the function?

Pragma udf is a way to speed up using PL/SQL functions in (user defined function), starting from version 12. If you want (more...)

Linux Perf Probes for Oracle Tracing

Topic: this post is about Linux perf and uprobes for tracing and profiling Oracle workloads for advanced troubleshooting.

Context

The recent progress and maturity of some of the Linux dynamic tracing tools has raised interest in applying these techniques to Oracle troubleshooting and performance investigations. See Brendan Gregg's web pages for summary and future developments on dynamic traces for Linux. Some recent work on applying these tools and techniques to Oracle can be found (more...)

RAM is the new disk – and how to measure its performance – Part 3 – CPU Instructions & Cycles

If you haven’t read the previous parts of this series yet, here are the links: [ Part 1 | Part 2 ].

A Refresher

In the first part of this series I said that RAM access is the slow component of a modern in-memory database engine and for performance you’d want to reduce RAM access as much as possible. Reduced memory traffic thanks to the new columnar data formats is the most important enabler for the awesome In-Memory processing (more...)

Linux Kernel Stack Profiling and Flame Graphs Applied to Oracle Investigations

Topic: This blog post is about kernel stack profiling and visualization with flame graphs with examples.

Stack profiling and flame graphs are very useful techniques and tools for troubleshooting and investigating workloads at the OS-level and understand which code path take most of the execution time. You can find extensive material and examples o flame graphs in Brendan Gregg's website and blog. A few additional examples of using stack tracing and flame graphs for (more...)

OEL/RHEL 7 – firewalld

How cool is getting Linux. Hope soon to not look like a Windows. If they put a butterfly or shiny window in the “start menu” I’m out of the game. The “new” firewalld is cool and dynamic, but my servers are square, boring and static. Maybe if I’m using RHEL/OEL 7 in my laptop it […]

SLES shell script to check required os packages according to documentation before starting oracle forms & reports installation

Hi!

If you try to install oracle forms & reports 11.1.2.2 on SLES 11.3 than despite all installer checks are passed maybe you get a message like:

Error in invoking target ‘install’ of makefile ‘<FR_HOME>/sqlplus/lib/ins_sqlplus.mk’.

The reuirement check of the installer shows only missing openmotif classes which are not really required on SLES (see Doc ID 1567715.1), but no problems with a compiler or something similar.


Checking for binutils-2.19-11. (more...)

Web Pages Not Databases – Part 2: Fail2ban, Apache, IP Addresses, Linux, SELinux

August 23, 2015 (Back to the Previous Article in this Series) I started using Linux in 1999, specifically Red Hat Linux 6.0, and I recall upgrading to Red Hat Linux 6.1 after downloading the files over a 56k modem – the good old days.  I was a little more wise when I upgraded to another […]

Preparing a Oracle Linux for a Vagrant box

This post is an overview of an installation and configuration process of the Oracle Linux, which will be used as a machine “box” for Vagrant software using a Virtual Box platform.

Post itself is divided into two parts:

  1. Oracle Linux installation (points 1 to 12)
  2. Vagrant box configuration (points 13 to 16)

Part 1 – Oracle Linux installation

 

1. Create a new Virtual Machine - machine name will be used later to create Vagrant (more...)

The Leap Second is No Laughing Matter (if you have java on an older Linux kernel)

Earlier this month we began getting frequent email warnings from our EM12c server that some agents were experience read time outs. Then we saw that the emagent java process was using A LOT of CPU, regularly around 500% but sometimes as high as 800% as seen from "top". Restarting the agent did nothing.

I opened an SR with Oracle Support, where I was first instructed to apply a JDBC patch and then a PSU agent (more...)

Installing Oracle XE, ORDS and Apex on CentOS – Part Four: Stress testing

This is part four in a series of blog posts about how to install Oracle 11g Express Edition (XE) with Oracle Application Express (Apex) on a CentOS Linux server, with Apex served by Oracle REST Data Services (ORDS) running on top of Tomcat and Apache.

After setting up a small CentOS server with Oracle Express Edition (XE), I wanted to stress test it to see how much load such a barebones installation can handle. In (more...)