Printing system call arguments in gdb

This blogpost is about how to print the system call arguments of a system call catches in gdb. The reason is I spend quite some time on searching for this, and working around this, so writing it in a blogpost might help others who spend their time in the gdb (more...)

Configuring VNC Server on Linux 6.3

This method applies to RHEL; let’s first install the VNC Server. Through yum command # yum install tigervnc-server Or Through RPM command First, locate and mount your RHEL 6.3 install media. [root@oraerp ~]# cd “/media/RHEL_6.3 x86_64 Disc 1/Packages” [root@oraerp Packages]# pwd /media/RHEL_6.3 x86_64 Disc 1/Packages   Install (more...)

Info about Exadata’s imageinfo and rpm’s

Recently we noticed that imageinfo was displaying the following information at a customers site. Imageinfo was not displaying data i suspected, so a quick little blogpost about what was going on there.

[root@dm01db01 ~]# dcli -g /opt/oracle.SupportTools/onecommand/dbs_group -l root "imageinfo | grep 'Image version'"
dm01db01: Image version: 11.2. (more...)

Sudo Keystoke Optimisation

If like me, and a couple of others I’ve spoken to recently, you were not previously aware of “sudo -s” then you might be interested to know that you can save yourself two keystokes by switching from:

sudo su -


sudo -s

From the man page:

The -s (shell) (more...)

UKOUG Tech13

I will be presenting on two topics at the UKOUG Tech13 conference in Manchester.

Goodbye KVM… Hello KVM - Monday (2nd December) @ 16:50 in Exchange 7 (45 mins) - If you use virtualisation in your “home lab”, but have never considered KVM then this session is aimed at you.

Pitfalls, Pain (more...)

Drill Down the I/O stack at UKOUG Tech13

It's just under a week to go before the doors open for the UKOUG Tech13 conference and the adjoining OakTable World UK 2013 sessions, so I thought I would write a very short blog post about what I will be doing there, where I'll be, and what I'm looking forward (more...)

Oracle Direct NFS (and Linux Routing) … for Dummies!

When I started my current role a few months ago, I was very interested to learn that direction had been set to migrate away from ASM and onto NFS storage that had some read flash cache in front of it. I'm not the world's biggest fan of ASM and the (more...)

Play: automate Start/Stop OSWBB on Linux

I installed OSWatcher on Linux and want to Start OSWatcher Black Box (OSWBB) every system boot. I suggest you download package on Oracle Support - How To Start OSWatcher Black Box (OSWBB) Every System Boot (Doc ID 580513.1). If not? You might write simple script.
[oracle@test12c ~]$ pwd

Tools that I use – nmap

For medium to large size projects the network setup can be quite complex, especially if it involves several external partners or third-party networks (VPN, MPLS etc).

Normally network changes are done by network engineers that do not have access to the servers and therefore cannot verify the changes they make.

When I have to verify a network change, firewall opening, NATing etc, I have in the past often used telnet.

This is very simple and (more...)

WebLogic Server and entropy

After input from Jacco H. Landlust and Edwin Biemond I have rewritten my post about entropy.


Entropy pool

In computing you often need random numbers. They are used for encrypting stuff but also for lots of other things.

For Linux servers random numbers are default provided by the /dev/random device. /dev/random is a pool of random bits (more...)

Bash script for installing WebLogic Server PSU patches via BSU

Patching WebLogic is necessary but not fun. To help out I have created a simple Bash script for installing CPU/PSU patches.

For information about CPU, PSU and SPU patches check this post.

The script is using BEA Smart Update so it is for WebLogic Server 12.1.1 and older. WebLogic Server 12.1.2 has switched from BSU to OPatch.

# ---------------------------------------------------------------------------
# Peter Lorenzen
# Version 0.9

IPython at Ohio LinuxFest 2013

Are you signed up yet for Ohio LinuxFest on Sep. 13-15? I'll be there to present

IPython for non-Pythonistas

Break out of your (bash) shell! IPython and the IPython Notebook have swept over the Python programming community, but they're not just for Python programmers - they make for high-powered shell (more...)

Configuring ODBC to MySQL from Oracle

Sometimes people want to connect to MySQL from Oracle and copy table data between the databases.  You can do that with Oracle Hetrogenous Services via ODBC.  This post will show how to create an odbc connection to your MySQL database which is the first part of this.

For my example, (more...)

oratop from MOS

This is just a pointer post to a tool which I discovered today. It is ORATOP, to monitor databases real time like top of unix flavours. It is pretty much like MOATS   (tool from Tanel Poder and Adrian Billington and RAC version by  Jagjeet Singh),   with a bit better output (more...)

Analyzing page allocation failures on Exadata

I have seen several clients who are struggling to decode page allocation failures on Exadata, in this post i will try to explain how to read the backtrace. The following is an anonymized client case where page allocation failures are leading up to a node reboot.

Jan 1 11:58:02 dm01db01  (more...)

Playing with VirtualBox, Oracle 12c ( and OEL 6.4 – Part 2

We will complete our lab by installing the Oracle Database software, create a Pluggable database and take a look in the Oracle Enterprise Manager Database Express.

The steps to install and create an Oracle Database 12c are:

1 – Go to the database directory created when unzipped the 2 Oracle (more...)

Dual-Boot on UEFI PCs: Booting Ubuntu only works randomly

In my posting about using ubuntu on a Windows 9 laptop, i ended with:
But now rebooting works like expected (with Ubuntu and Windows 8).
After some more reboots and trying to start ubuntu, booting ubuntu only works randomly. Sometimes it worked after walking through BIOS/UEFI. Sometime it did (more...)

Linux and UEFI: Files, Mountpoints, Commands…

With Windows 8 secure boot is used. That means if you want to add a Linux kernel, this kernel has to be signed. After installing Ubuntu on a Windows 8 machine, here the directory listing of the /boot directory:
-rw-r--r-- 1 root root   844882 Okt  9  2012 abi-3.5.0-17-generic

Using Ubuntu on a Windows 8 Laptop: because of UEFI more problems as expected

Today i tried to install Ubuntu on a Windows 8 Laptop. First thing: you have to use 12.04 or greater because Windows 8 uses secure boot with UEFI.

But after the first boot with a USB-stick i got:

(initramfs) Unable to find a medium containing a live file system
?? (more...)

Linux Installfest, Dayton, Sat April 13

Dayton folks - are you coming to the Dayton Linux User Group's Installfest tomorrow?

The main point of our Installfests is to get everyone together for mutual help setting up and configuring computers and programs. But we like to throw in some educational talks, too, and I volunteered to give (more...)