Enable autologin in Debian with Systemd

19 05 2017

For allow autologin in a Debian system with systemd (very usefull with testing virtual machines):

Create dir:
mkdir /etc/systemd/system/getty@tty1.service.d/

Create file /etc/systemd/system/getty@tty1.service.d/override.conf with the following content:
ExecStart=-/sbin/agetty --autologin root --noclear %I $TERM

More info:

Disable time sync between host and guest in Linux VirtualBox

19 05 2017

To the following files:

/home/[your_user]/VirtualBox\ VMs/[VM_Name]/[VM_Name].vbox

Add the line:

<ExtraDataItem name="VBoxInternal/Devices/VMMDev/0/Config/GetHostTimeDisabled" value="1"/>

More info:

Deny ssh access to one user

18 05 2017

If you want to deny the access of one user (or group) to a server via ssh, these are the steps for a Debian/Ubuntu server:

Add the user to /etc/security/access.conf
- : user1 : ALL

Assure that “/etc/ssh/sshd_config” have the following line (by default yes):
UsePAM yes

Assure that “/etc/pam.d/sshd” have uncommented the following line:
account required pam_access.so

Configure phpmyadmin for connect to RDS AWS MariaDB

30 03 2017

Ensure that “/etc/phpmyadmin/config-db.php” doesn’t haven any configured values:


Create a new file with for your particular values in “/etc/phpmyadmin/conf.d/myconf.php”

<?phpConfigure phpmyadmin for connect to RDS AWS MariaDB
$cfg['Servers'][$i]['extension'] = 'mysql';
$cfg['Servers'][$i]['host'] = 'name.of.rds.amazonaws.com';
$cfg['Servers'][$i]['connect_type'] = 'tcp';
$cfg['Servers'][$i]['compress'] = TRUE;

Go to the phpmyadmin website and log with the administrative account.

More info: http://stackoverflow.com/questions/4402482/using-phpmyadmin-to-administer-amazon-rds

Dell Inspiron 1545 upgrade – Enable virtualization in BIOS and change CPU

27 02 2017

The Dell laptop Inspiron 1545 doesn’t have any menu in the BIOS for enable virtualization, but using a tool from Dell allow us to enable it from the operating system.

The tool was called Dell Client Configuration Toolkit – CCTK and was available here:

But they change the name, and now it is called Dell Client Command Suite, and then, Dell Command | Configure. Download it from the following links (maybe they don’t change it again, who knows…):

The latest version of CCTK is now Dell Command | Configure and is a part of the Dell Client Command Suite.

It is possible to do it from linux, in my case a .deb package is available. Download and install it. After, execute the following (search for the binary before):
# cctk --virtualization
# cctk --virtualization=enable

In my case, the CPU is an old Pentium Dual Core T4300 2.10GHz, 800MHz FSB, 1MB cache and I need to change the processor too, this doesn’t have the vmx instruction support. The requirements are:

1. The CPU should be a socket P CPU with 478 pins (P-series processors were more energy efficient than T-series)
2. More or equal than 1MB cache
3. More or equal than 800Mhz FSB, maybe close to 1066Mhz.
4. Core 2 duo preferred, if not, any Celeron ,Celeron Dual-Core or Pentium Dual-Core

For the upgrade, I choose a the Intel Core 2 Duo P9500 SLB4E 2.53Ghz 6M 1066Mhz. It works perfect, the fan is running less time, the temperature is lower and the perfomance is better. Change it if you have the opportunity.

Replacing it was very easy, unlock the bottom cover, unlock 5 screws from the heat pipe and unlock the screw of the CPU (half turn only), remove, mount the new one with some thermal paste and attach the heat pipe and the cover.

More info:


Install VMware Horizon Client in Debian 8 Jessie

24 02 2017

Download the linux client from the VMware website:


The downloaded file is a bash script, execute it from a privileged user:

# bash VMware-Horizon-Client-4.3.0-4710754.x64.bundle

Install dependencies:

# apt-get install libudev-dev libffi-dev libglibmm-2.4-dev

Before finish the install, click into the “Scan” button. If libffi.so.5 is missing and you have libffi.so.6 only (usually in a modern Debian), create a symlink for bypass:

cd /usr/lib/x86_64-linux-gnu && ln -s libffi.so.6 libffi.so.5

Probably, if you execute now the client, it doesn’t start because the following:

$ vmware-view
/usr/lib/vmware/view/bin/vmware-view: error while loading shared libraries: libudev.so.0: cannot open shared object file: No such file or directory

Solve that creating a simlink:

# cd /lib/x86_64-linux-gnu && ln -s libudev.so.1 libudev.so.0

And run!:

$ vmware-view

Multiple network interfaces with multiple public IPs in an EC2 instance with different outbound source using network namespaces

14 02 2017

In this scenario we will have an ec2 instance with:

* 3 network interfaces
* 3 public IPs (one for each interface)
* 3 different process with different public outbound address running in separate network namespaces

As starting point, we have a simple ec2 instance with one interface and a public IP assigned to it. The steps are:

– Allocate two new elastic IPs

– Create two new network interfaces in the same subnet in which resides the instance.

– Associate the new elastic IPs to these new network interfaces.

– Associate the new network interfaces to the instance. Now, it have the default eth0 and two more, eth1 and eth2.

– Create a pair of network namespaces for the new interfaces:

ip netns add blue
ip link set eth1 netns blue
ip netns add green
ip link set eth2 netns green

– Request the IPs for the interfaces:

ip netns exec blue dhclient eth1ip netns exec green dhclient eth2

– And test it:

curl ipinfo.io/ip
ip netns exec blue curl ipinfo.io/ip
ip netns exec green curl ipinfo.io/ip

Take into account that:

– You need to launch the proces with the “ip netns exec xxxx” due that systemd don’t support the network namespace assignement.

– Look the limits of AWS, by default, only 5 EIPs are allowed and each type of instance have a network limit.