OSWatcher integration in Trace File Analyzer (TFA)

Some time ago I wrote a post about using OSWatcher for system analysis. Neil Chandler (@ChandlerDBA) rightfully pointed out that although OSWatcher was cool, TFA was the way to go. TFA can include OSWatcher, but more importantly it adds a lot of value over and above what OSWatcher does.

I guess it depends on what you want to do-I still think that OSWatcher is a good starting point and enough for most problems on single (more...)

Developer Days VM Startup and Shutdown, SQLcl

| Jun 16, 2016
If you're developing on a remote platform, chances are that you are using a Virtual Machine. (VM)  In Oracle, we release a virtual machine called the  "Oracle Developer Days".    This is available on the Oracle Technology Network and ala google.  Todays hack is setting up headless vm's, ports and aliases to speed up your day. (This post took a lot longer to write that the aliases we set up!)

For this (more...)

Can’t Display 256 Colors

If you’re reading this post, you most likely are trying to run the Oracle Database 11g or 12c runInstaller program, and it’s failing a critical dependency check and displaying an error like the one below. If so, choose n because if you choose y it won’t launch the Oracle Installer.

Starting Oracle Universal Installer...
Checking Temp space: must be greater than 500 MB.   Actual 30824 MB    Passed
Checking swap space: must be greater than  (more...)

Linux BPF/bcc for Oracle Tracing

Topic: In this post you will find a short discussion and pointers to the code of a few sample scripts that I have written using Linux BPF/bcc and uprobes for Oracle tracing.

Previous work and motivations

Tools for dynamic tracing are very useful for troubleshooting and internals investigations of Oracle workloads. Dynamic tracing probes on the OS/kernel, can be used to measure the details for I/O latency for example. Moreover probes on the Oracle (more...)

New Installation Cookbook: Oracle Linux 6.7 with Oracle RAC

cookbookI’ve updated my install cookbooks page to include a new cookbook for installation of Oracle 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.



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...)

Linux Perf Probes for Oracle Tracing

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


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...)

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 […]

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...)

Installing Oracle XE, ORDS and Apex on CentOS – Part Three: Additional configuration

This is part three 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.

By now, you should have a working installation of CentoOS with Oracle XE, Apex, ORDS, TomCat and Apache. There are still some additional configuration and optimization we should do, which (more...)

Installing Oracle XE, ORDS and Apex on CentOS – Part Two: Installation

This is part two 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.

Let's get right to it, starting with Oracle XE.

Installing Oracle XE

This is actually quite straightforward, assuming you have followed the prerequisite steps in part one.

As part of (more...)

#FISMA Ready @Ubuntu LTS @18F

Ubuntu is a very popular operating system (OS) in the cloud space but the Federal government has been reluctant to adopt Ubuntu, preferring to stick with Redhat as their Linux flavor of choice.  As the Government moves toward the cloud it makes sense to me that Ubuntu would start to see some more play time.  One of the big hurdles to this is the need to ensure that Ubuntu meets the Federal Information Security Management Act (more...)

Exadata and Bash Shellshock

There has recently been a lot of news about the exploit revealed in the bash shell.  While the fix is very quick to implement, there are a couple of tricks that are required to install this update on an Exadata environment.  According to Oracle support note #1405320.1, Exadata storage server versions 11.2.3.x.x and 12.1.1.x.x are susceptible to the exploit.  On a typical Oracle Enterprise Linux, a simple (more...)

Where is my space on Linux filesystem?

Not Often, I checked about my space after made filesystem on Linux. Today, I have made Ext4 filesystem around 460GB, I found it 437GB only. Some path should be 50GB, but it was available only 47GB.
Thank You @OracleAlchemist and @gokhanatil for good information about it.
Filesystem                   Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup0-U01LV   50G   52M   47G   1% /u01

Reference  - (more...)

Extend linux partition on vmware

It was a quiet day, I worked as System Administrator and installed Oracle Linux on Virtual Machine guest. After installed Operating System, I wanted to extend disk on guest. So, I extended disk on guest. Anyway, I came back in my head what I was supposed to do on Linux then ? 
- Create new disk (and Physical Volume) and then add in Volume Group.
Checked my partition:
[root@mytest01 ~]# fdisk -l (more...)

Switch CentOS to Oracle Linux – centos2ol.sh

My time has used much with Linux. Some people asked to move from CentOS to Oracle Linux somehow. I used to believe it easy to do like that. Anyway, It'd better to test. 
I focused on 2 links.

Oracle introduces centos2ol.sh script that can convert CentOS 5 and 6 systems to Oracle Linux. After that run "yum upgrade" again.
[root@test-centos ~]# uname -r
2.6.32-431.29. (more...)