Last week I setup dual boot on my Laptop for giving Gnome on Debian a try. Worked without any problems, except the sound, the driver was installed correctly, but still had no sound. After reading loads of docs I found the hint of using the Realtek Code-Software here. Here step-by-step what I needed to make it working:


apt-get install linux-source linux-headers-3.0.0-1-all-amd64 build-essential

get file from realtek - choose your kernel

become root

su root

uncompress file (example!)

tar -vxjf LinuxPkg_5.17Beta.tar.bz2

change to new dir (example!)

cd realtek-linux-audiopack-5.17

do the installation and reboot


Today I tried to restore a full backup of an old DB to a new database with

what resulted in
RMAN-06026: some targets not found - aborting restore
RMAN-06023: no backup or copy of datafile 6 found to restore
After looking for the solution for hours I found out that there is a 5-year!!! old bug open that makes it impossible for RMAN to restore a backuppiece if it's read-only.
The BUG# is "5412531 - RMAN FAILS RESTORING READONLY BACKUPS: ORA-19870 ORA-19587 ORA-27091 ORA-27067"

I am using sqlplus and rman on linux a lot, and one very annoying thing is that there is no history (key-up) as it is on windows. Reason is that in sqlplus/rman is running in a dosbox and the dosbox has the "key-up-history" feature implemented automatically.

But also in Linux it's easy to achieve. The tool you need is "rlwrap". Just install it (example for Debian)

apt-get install rlwrap

and call sqlplus with "rlwrap sqlplus" or rman with "rlwrap rman".

Nothing more to make it run? No, nothing more!

Have fun!

If you are using UTL_MAIL you will soon come to some limits of this package.

  •  it does not support SMTP authentication
  •  it does not support attachments (not provided here)

Last week I needed the authentication part for a project.
I decided to take something that's already stable ready to be used, and free.
It's Apache Commons Mail part. Basically these class makes handling in Java much easier than provided by SUN/ORACLE.
es, it's a Java-class. But Java is really easy to use in Oracle, you will see.

Basically you get the jar, say "loadjava myjar.jar", create a simple java-class in oracle, create a simple pl/sql wrapper.
This cooking recipe is on Linux, but except the unpacking it's almost the same on windows.
And don't forget to take the most current and stable jar-files!

get the mail.jar from here

get the commons-email-xxx.jar from here

unzip both in a directory on your database server and use following statements to load it into the database (REPLACE USER/PW!!!):


loadjava -u myuser/MYPW -resolve mail.jar
loadjava -u myuser/MYPW -resolve commons-email-xxx.jar


Now we need some Java and PL/SQL programming. I did the design so that it can be basically used instead of UTL_MAIL, means same parameter names and default-values.

Just some more parameters were added for using the authentication.
You can download the files from the download-sections here. Just install them with SQL/PLUS or whatever tool you like.

After compiling the programs into the databse give it a try. You need to set some permissions, so keep DBMS-Output enabled, in the output you find the statements that needs to be executed. It will look like similar to this:

dbms_java.grant_permission( 'yippie', 'SYS:java.lang.RuntimePermission', 'accessDeclaredMembers', '' );
dbms_java.grant_permission( 'XYA', 'SYS:java.util.PropertyPermission', '*', 'read,write' );
begin dbms_java.grant_permission( 'XYA', '', '123...', 'connect,resolve' ); 


Ok for testing we need a testscript:



dbms_java.set_output(1000000); std_mail.send(
sender => This email address is being protected from spambots. You need JavaScript enabled to view it.',
recipients => This email address is being protected from spambots. You need JavaScript enabled to view it.', subject => 'subjective', message => 'messagemessagemessage', smtphostname => '', smtpport => '587', smtpuser => 'myuser', smptpassword => 'mypw', useTls => false); END; /

That's it!

The programs here are released under the GNU/GPL2.

Have fun!

Feedback appreciated, please comment!

If you are running into a ORA-07445 or ORA-00600 error something you should fix immediately happened on your Database. You should do following things before opening a TAR on Metalink:

  • get the exact error-message including the things in the square brackets from the alert-log
  • logon to metalink and search for the document 153788.1 that's the Error-Lookup-Tool from Oracle for these errors and open that document
  • choose if it is a ORA-00600 or a ORA-07445 and enter the things in the first square brackets into the field "Error Code First Argument" and press "Lookup Error"

If you are lucky and find informations/patches (what pretty often happens -> good stuff Oracle) you can probably fix it by yourself. If not you have to open a Metalink-TAR.

androidCurrently I reinstalled my Samsung Galaxy S (with insanity 6.3) and came across "an error occured while downloading your recovery." when trying to flash clockworkmod recovery. With installing a superuser version from the market and reinstalling clockworkmod my problem seems to be solved. There seems to be a bug in the superuser app I was using previously.

kvm I recently installed a usb-harddisk on my server and mounted it on a guest with virt-manager. The performance was very bad, i had 50Kbyte when testing with hdparm.

I remounted it in virt-manager as IDE drive instead of USB-Drive and voila i had full performance again. It seems that the USB-drive mounting is a bit bugged.

kvm I am using KVM for a while now and reinstalled my XEN-Server. I have to mention it's not the same hardware. XEN was on a 2 year old Server with 4G memory and Debian Lenny32, KVM is on a 6 months old 8G memory Server with Debian Squeeze. So i have a bit better hardware and a 64bit System on KVM.

I like that KVM is out-of-the-box working with virsh/virt-manager the performance improvement is enormous, especially with 64MB-RAM systems like I use for my wiki. I use LVM for the guest-disks (I did it even for the XEN-guests) and compared to use files it's even a huge performance improvement.

The only thing that's easier in XEN is that you can mount the guest-partitions and can access them directly in KVM you need to use kpartx (not hard but one step more) to achieve this.

I started to move to KVM because it seems as XEN development slowed down and there is much more development activity and support for KVM. I think that was a good decision.




I recently needed to install a Oracle 11g Database on Debian, and wrote down the notes here. Please send me a message

if i missed a step or something is easier to achieve than I did.

install mandatory packages

some packages are probably not necessary, I put them together from old notes from me and several weblinks if you know which are not necessary send me a list and i will correct it

apt-get install binutils autoconf automake bzip2 gcc less libc6-dev make libstdc++5 unzip zlibc build-essentials libaio1

!!!doxygen reported as not needed by Tobia, tx for this! Also watch his comment if you use OpenVZ!


I chose fluxbox but you can also take anything else like xterm, gnome, kde….

apt-get install fluxbox

prepare user and groups

groupadd oinstall
groupadd dba
useradd oracle -m -d /home/oracle -g oinstall -G dba -s /bin/bash
passwd oracle

check environment

there are several kernel parametersw that have to be changed to succesfully install the database, here is a script that helps you to determine them

echo "sem: ";echo "min 250 32000 100 128"; echo "is " `cat /proc/sys/kernel/sem`; echo; \
echo "shmall: ";echo "min 2097152"; echo "is " `cat /proc/sys/kernel/shmall`; echo; \
echo "shmmax - should be able to hold the SGA - max 4G-1byte: ";echo "is " `cat /proc/sys/kernel/shmmax`; echo; \
echo "shmmni: ";echo "min 4096"; echo "is " `cat /proc/sys/kernel/shmmni`; echo; \
echo "file-max: ";echo "min 6815744"; echo "is " `cat /proc/sys/fs/file-max`; echo; \
echo "ip_local_port_range: ";echo "min/max 9000  65500"; echo "is     " `cat /proc/sys/net/ipv4/ip_local_port_range`; echo; \
echo "rmem_default: ";echo "min 262144"; echo "is " `cat /proc/sys/net/core/rmem_default`; echo; \
echo "rmem_max: ";echo "min 4194304"; echo "is " `cat /proc/sys/net/core/rmem_max`; echo; \
echo "wmem_default: ";echo "min 262144"; echo "is " `cat /proc/sys/net/core/wmem_default`; echo; \
echo "wmem_max: ";echo "min 1048576"; echo "is " `cat /proc/sys/net/core/wmem_max`; echo; \
echo "aio-max-nr: ";echo "max 1048576"; echo "is " `cat /proc/sys/fs/aio-max-nr`; echo;

change necessary parameters

you have just to change the parameters that don't fit, but feel free to set them all to the minimum with this script

echo "kernel.sem = 250 32000 100 128" >> /etc/sysctl.conf
echo "kernel.shmall = 2097152" >> /etc/sysctl.conf
# !!!! needs to fit YOUR SGA (=main memory for database, be sure to have enough ram for PGA etc.)!!!!
echo "kernel.shmmax = 1200000000" >> /etc/sysctl.conf
#echo "kernel.shmmni = 4096" >> /etc/sysctl.conf
echo "fs.file-max = 6815744" >> /etc/sysctl.conf
#echo "net.ipv4.ip_local_port_range = 1024 65000" >> /etc/sysctl.conf
echo "net.core.rmem_default = 262144" >> /etc/sysctl.conf
echo "net.core.rmem_default = 262144" >> /etc/sysctl.conf
echo "net.core.rmem_max = 4194304" >> /etc/sysctl.conf
echo "net.core.wmem_default = 262144" >> /etc/sysctl.conf
echo "net.core.wmem_max = 1048576" >> /etc/sysctl.conf
echo "fs.aio-max-nr = 1048576" >> /etc/sysctl.conf

change some limits

also some limits have to be set

echo "oracle soft nproc 2047" >> /etc/security/limits.conf
echo "oracle hard nproc 16384" >> /etc/security/limits.conf
echo "oracle soft nofile 1024" >> /etc/security/limits.conf
echo "oracle hard nofile 65536" >> /etc/security/limits.conf

create directories

I prefer to separate software, database files and recovery files so i put them in /u01 /u02 /u03

mkdir -p /u01/app/oracle
mkdir -p /u02/oradata
mkdir -p /u03/flash_recovery_area
chown -R oracle:oinstall /u01 /u02 /u03
chmod -R 775 /u01 /u02 /u03

NOTE: seems they just say “recovery_area” or even “fast_recovery_area” now to the “flash_recovery_area”
additional steps

These steps prevent errors when the installer links some libraries

ln -s /usr/bin/awk /bin/awk
ln -s /usr/bin/basename /bin/basename

finish preparations


== call the installer But before calling the installer check with above script if the kernel parameters are fine now

su oracle
/pathtoinstallfileshere/database/runInstaller -ignoreSysPrereqs


The installer should guide you through each step in simple and advanced mode. When the requirements are checked you can savely bypass the warnings, because not everything can be checked on an unsupported ;-) environment.

!!!I really want to keep this up-to-date so please send me a note if i missed something or something is easier to handle than i did it!!!

Errors that can happen and how to bypass them

Added at 30.12.2010 including some more install packages some of the errors below did not happen when i wrote this article, it seems some new library versions etc. changed recently

java exception when calling the installer

happened at my side because I installed it over vnc This should help:

xhost localhost

Error in invoking target 'install' of makefile

seems to be a problem with a newer? glibc version in the make.log file you should find something like

warning:, needed by /u01/app/oracle/product/11.2.0/dbhome_1/ctx/lib//, not found

simply install libstdc++5 apt-get install libstdc++5

android"The type R is already defined"
That's the message you get in Eclipse if you try to build the Funambol Android Sync Client.
Reason is that you have checked two Builders that try to generate the same class.
You just have to uncheck the Java-Builder from Project->Properties->Builders.
Then the application even works fine in the Emulator.


Some time ago (after noticing my stuff was not working anymore Cry), I wrote a Utility Class for the Amazon Product API. I now published it as part of my new Amazon Tools project, that can be downloaded as complete class with examples here. It's licensed under Simplified BSD License.


* signs the request Url for the Amazon API
* @param str pUrl unsigned Url
* @param str pSecretAccessKey it's a hash to sign the Url,
* you get that from the Amazon-Partner network
* together with your AccessKey
* @return signed Url

function &signRequestUrl($pUrl,$pSecretAmazonHash){
// retrieve Parameter from urls
$arrUrlParts = parse_url($pUrl);
$vParams = $arrUrlParts['query'];
// parameters are separated by & so we put them in
// another array, in there are values like "aa=bb" "xx=yy"
= explode('&',$vParams);

// loop and put pair/values in array
foreach($arrParams as $vPair){
// easy separating of the name/val by using explode
$arrPair = explode('=',$vPair);
$arrParamsSort[$arrPair[0]] = $arrPair[1];
// Timestamp needed if there is none present
$arrTemp = array_change_key_case($arrParamsSort,CASE_UPPER);
// format from amazon-docs
if (empty($arrTemp['TIMESTAMP'])){
$arrParamsSort['Timestamp'] = gmdate('Y-m-d\TH:i:s\Z');
// sort the array, needed to make the Url canonical
// canonical means that the parameters are sorted
// so it's easier to check if urls are different
$vCanonicalString = '';
foreach ($arrParamsSort as $vKey => $vVal){
// rawurlencode => 5.3 should be RFC 3986 compliant
// for php versions below this should do the job
$vNewVal = str_replace('%7E','~', $vVal);
$vCanonicalString = $vCanonicalString.$vKey.'='.rawurlencode($vNewVal).'&';
// remove last &
$vCanonicalString = rtrim($vCanonicalString,'&');
// from he amazon docs
$vSignString = "GET\n".strtolower($arrUrlParts['host']).

// generate the hash from the request
$vSignature = hash_hmac('sha256',$vSignString,$pSecretAmazonHash,true);
// and base64 encode it
$vSignature = rawurlencode(base64_encode($vSignature));
// rebuild the url with the signature
$vRet = $arrUrlParts['scheme']."://".$arrUrlParts['host'].

return $vRet;



I was looking for a solution to use multiple desktops in Windows7 like its possible on Linux since.... ever?

To use multiple desktops is very convenient if you develop software, a lot of application are often just used once ore twice a day but you have to tab through them very often. There seems to be no solution from Microsoft, and i could not really find any other good solution, until i ran over Virtual Dimension. The last update was in 2005. I was very skeptical because the software was not maintained for over five years. But... this is why i write this article its GREAT STUFF!. Why?

  1. it installs pretty fast and is pretty small (~400k)
  2. very easy to configure, intuitive handling
  3. possible to use drag and drop of the applications (you can move your applications between the desktops

I dont know how it can be possible that somebody writes software that works for five years on different OS versions, but its incredible.


I hope Francois Ferrand will continue to work on this project.