Masquerading or replacing outgoing SMTP email address with Postfix

Postfix can replace an outgoing email address by another one. To do so, you must perform these steps: Add in /etc/postfix/main.cf the following line smtp_generic_maps = hash:/etc/postfix/generic_maps Add in hash:/etc/postfix/generic_maps a

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Create an ext3 or an ext4 partition without a journal

Most of the time, having a journal for ext3 and ext4 partitions is pretty useful. Nevertheless, you can prevent creating a journal by adding the option ^has_journal. For example: mkfs

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Initializing a brand new disk with “parted”

“parted” is a replacement for “fdisk” of Linux.  It can handle disks larger than 2 TB.  Issue this command to launch “parted” where /dev/sdL is the disk you want to

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How to download Android source code

Source code of Android can be downloaded by following these steps: $ mkdir ~/bin $ PATH=~/bin:$PATH $ curl https://dl-ssl.google.com/dl/googlesource/git-repo/repo > ~/bin/repo $ chmod a+x ~/bin/repo $ mkdir WORKING_DIRECTORY $ cd

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Installing the Android Development Environment for Windows 7

This post lists the main steps in order to install an Android development environment for Windows 7.  The developement environment relies on Eclipse.  Download a JDK (7u3)  from the following

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How to unmount an encrypted partition?

Unmount the partition umount /mnt Unmap the partition cryptsetup luksClose securebackup

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How to mount an encrypted partition?

Map the partition cryptsetup luksOpen /dev/sdXN securebackup Mount the partition mount /dev/mapper/securebackup /mnt

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How to setup partition encryption?

To setup partition encryption on Ubuntu, perform the following steps: Install the required software apt-get install cryptsetup For more security, erase the partition you want to encrypt with one of

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How to backup and restore Windows 7 activation files

It is possible to backup and restore the activation status of Windows 7 Backing up the activation files To backup the activation status, backup the following files. Administrator access rights

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How to use the loop device on Unix?

The loop device on Unix lets access a file as a block device.  Disks are block devices.  So, it is possible to use a file as a disk.  The first

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How to control the brightness of the display from command line?

You can set the brightness of the display by issuing this command within a shell echo 3 > /sys/class/backlight/acpi_video0/brightness where 3 is the brightness level. Its value is from 0

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How to restore the normal scroll bars in Ubuntu 11?

Simply create a file named /etc/X11/Xsession.d/80overlayscrollbars and put into it the following line: export LIBOVERLAY_SCROLLBAR=0 or simply execute the following command echo “export LIBOVERLAY_SCROLLBAR=0” > /etc/X11/Xsession.d/80overlayscrollbars You need to do

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Install Ice Cream Sandwich on a Google Nexus S

I have installed Ice Cream Sandwich (ICS) on a Google Nexus S. It works perfectly. The process is not complicated but requires some basic technical skills. What’s interesting about the process

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Converting a certificate from DER to PEM or PEM to DER

openssl x509 –in input.pem –inform PEM -out output.der –outform DER openssl x509 –in input.der –inform DER -out output.pem –outform PEM

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How to remove the passphrase on a private key

To remove a passphrase on a private key, simple execute this command. openssl rsa -in server.key -out server.unprotected.key Since it is a private key, make sure that it is well

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Creating a certificate for a server

Creating a server certificate involves only a few steps. To do so, execute the following commands. This post assumes that “OpenSSL initial configuration” and “Creating a ca’s self signed certificate”

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Creating a ca’s self signed certificate

In order to create your own certificates, you need a CA (certificate authority) certificate. This certificate will be used to sign every certificate you will create. To do so, execute

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Tomcat and MySQL benchmarks

Benkmarks made using a Tomcat and a MySQL database. These figures are provided to give you an idea of the performance you should expect. The tests were done in the

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OpenSSL initial configuration

This initial configuration procedure assumes that you are executing it on Linux Create a special user named ‘ca’. Its home directory will hold the data. It must protected carefully. For

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How to change the signature of a disk

To change the signature of a disk under Windows 7, follow these steps are: Run the command line utility diskpart as the administrator user Execute the command “list disk” to locate

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