3Aug/170

Available now: Fedora 26 and Suse Leap 42.3

As of today, we offer you the brand new Fedora 26, it replaces the previous version 25. Additionally, Suse Leap was updated as well and the latest version 42.3 is available at Contabo!

Both operating systems can be combined with the Software RAID 1 and Webmin. In addition, Fedora 26 can be installed via VNC as well.

Being an existing customer, you can easily upgrade to the new versions through your customer control panel.

We always offer you a large selection of Linux distributions (as well as Windows Server 2012 and 2016). Just click on "Customize & Order" below your desired (virtual) server model in order to get a detailed overview and select the operating system of your choice!

Please note: You can find further information and a product overview on our website!

Posted by: Markus | Tagged as: , , , , , No Comments
19Jul/170

Analysing log files in Windows and Linux

Everyone knows the scenario, you want to analyze an issue of your server or local computer but where to find all those log files?

In the following tutorial we are going to analyze specific log files in Linux and logs in the Windows Event Viewer. An additional chapter will go through the log analysis via Systemd.

Linux log files

Unfortunately, it is quite different from distribution to distribution, which information can be extracted from specific log files. In the following we will analyze the log file structure of Debian 8 and CentOS 7.2. The first location to look for log files should always be /var/log/. Depending on their configuration, Apache, Nginx or similar applications write log files to this folder too. System log specifications and locations can be found in the file /etc/rsyslog.conf.

Debian 8:

  • /var/log/auth.log

Logs of successful and failed authentications to your system can be found in this log file. It is also logged when a user invokes commands via sudo.

  • /var/log/messages

This file contains log entries of general system information, amongst others, you will also find the system upstart logs.

  • /var/log/dmesg or dmesg

The kernel ring buffer can be read with dmesg. You will find information about the system upstart, runtime kernel module messages and many further messages according to the hard and software of your system. By default, dmesg shows the full ring buffer. However, the output can be customized by adding specific parameters. A thorough documentation can be found on the manual page (man dmesg).

  • /var/log/syslog

This is one of the most important log files in general. Every Linux process is free to log to the syslog by implementing the syslog interface. It also logs the system upstart and executed cron-jobs.

CentOS 7.2:

As the log file structure is quite similar to the one of Debian 8, we will just mention the differences.

  • /var/log/secure

This log file is the equivalent to /var/log/auth.log in Debian systems. All kind of authentications are logged here.

  • /var/log/messages

There is no separation of /var/log/messages and /var/log/syslog in CentOS, all system logs of processes which implement the syslog interface can be found here.

  • /var/log/cron

Cron specific log files are not part of the syslog as in Debian. They can be found in the above mentioned file.

 

Log analysis via Systemd

Systemd is basically the standard Init system of nearly all major Linux distributions today. Since at least April 2015, when Debian and Ubuntu switched to Systemd, every Linux administrator or user has been in touch with Systemd. As Systemd is a complex system, we will only take a look into the log analysis functionality provided. Every process in Systemd is identified as a unit. All active units can be shown via the following command:

systemctl list-units

When appending the parameter --all, this command also shows all inactive units.

Logs being created by Systemd are managed in the so called Journal. These logs can be accessed via the journalctl binary. If journalctl is called without any parameter, it will print out the whole Journal. However, it is also possible to output the log entries of specific units only. In the following example, we are going to analyze the log files of the Apache web server.

journalctl -u httpd

It is also possible to restrict the output with the parameters --since and --until.

journalctl -u httpd --since "2016-11-01 20:00:00" --until "2016-11-03 20:00:00"

The above command will output the Apache log entries between 2016-11-01 20:00:00 and 2016-11-03 20:00:00. It is also possible to use keywords like "today" or "yesterday".

You can also output the log files of more than one unit at the same time. In the following example we will output all Apache and Nginx log entries which have been logged since yesterday.

journalctl -u httpd -u nginx --since yesterday

If the parameter -f is used, all desired log entries are shown in real time.

The above was only a slight view into the possibilities of journalctl, there are several other useful features which are described on the manual page (man journalctl).

 

Log analysis via Windows Event Viewer

Windows Event Viewer Overview

In the above picture in the left navigation you can see the entry "Windows Logs". The following entries are most important.

  • Application

This entry will show the events of locally installed applications.

  • Security

Here you can see successful and failed login attempts.

  • System

This entry logs operating system internal events and errors.

Via the entry "Custom Views" -> "Server Roles" -> "Remote Desktop Services" you can see RDP related events and errors.

Potential hardware issues can be identified via "Application and Service Logs" -> "Hardware Events".

Useful for error analysis can also be the overview which can be seen via "Overview and Summary" -> "Summary of Administrative Events", it provides a summarized overview of the system status in general.

20Jun/172

New OS: Debian 9 available now!

Just released a few days ago, already available at Contabo: Debian 9, codename Stretch. You can order the operating system with your new VPS or dedicated server. Existing customers can upgrade to Debian 9 through their customer control panel.

You can combine Debian 9 with Webmin, Lamp, Webmin+LAMP and the Software Raid 1.

In its latest version, the developers have replaced MySQL with MariaDB, and a new Kernel version 4.9 is available as well.

Apart from Debian 9, we offer you a large number of Linux distributions, as well as Windows Server 2012 and 2016. Simply click on "Customize & Order" on our VPS and dedicated servers overview sites and select the operating system that matches your requirements - further details can be found on our website!

Posted by: Markus | Tagged as: , , , , 2 Comments
31Mar/170

Being spoilt for choice – Windows or Linux?

The operating system is the centrepiece of a server. You can imagine how important it is to choose a fitting operating system. For servers, two operating systems have established themselves: Windows and Linux. In this short overview, I'd like to present you the main differences between those two operating systems.

 

You might have heard that Windows is less stable compared to Linux. This actually was the case 15 years ago. Older Windows Server operating systems tended to operate rather unstable at times. However, Windows Server developed into an utterly robust operating system during the past years. Nowadays, you won't find much of a difference between both operating systems regarding stability.

Let's come down to the first real difference: Interface and Remote Access, which certainly are the most obvious differences between Windows and Linux.
With Windows Server, you access your server remotely with a protocol developed by Microsoft called RDP. The software used to connect to your server remotely, Remote Desktop Connection, is installed on every Windows machine by default, regardless of whether it's a Desktop or a Server version.

remote_en

Once connected to the server, you'll find a familiar Windows interface you already know from your Windows PC you use at home.

remotedesktop2

And that is probably the biggest advantage of Windows Server. Web server, DNS server, or other services, everything can be managed with a graphical user interface.

 

On Linux, this is totally different. While desktop versions come with a graphical interface as well, in server versions, you won't find one there for the benefit of performance. Also, you cannot access it using RDP, but via SSH.
Windows operating systems do not have an SSH client installed by default, therefore you have to install such a client on your own. There are plenty of them on the market, a well known and established client is PuTTY.

putty

Unlike on Windows Servers, there won't open a Desktop environment, but only a command line.

putty2

Administering the server is done exclusively via commands you type into the command line. While the experienced Linux user knows the most important commands, users who are new to Linux will probably have some trouble here, which could cause problems regarding server security and stability.

 

You might already know that Windows Server, unlike most Linux operating systems, is not for free. Microsoft fees a monthly amount for licensing their products. The amount of this fee differs, it depends on the hardware of the server running the operating system and the version of Windows Server.

 

Basically, every service can be realised on both Linux or Windows Server. The choice is mostly a matter of taste.

13Dec/160

NEW operating system available at Contabo: Arch Linux

Great news: From now on we offer you a completely new operating system, namely Arch Linux! It is available for all your VPS and Dedicated Servers! What's even better: Arch Linux will always be up to date, which means you will always get the latest version!

You can combine it with the Software RAID 1 and an installation with a manual configuration is possible as well - for further details, kindly contact our customer support!

Our existing customers know it already:

We always offer you a wide range of the latest Linux distributions (as well as Windows Server 2012 and 2016!). Simply click on "Customize & Order" below your desired (virtual) server model to get a detailed overview. Then scroll down a bit and select your OS of choice!

Further information and a product overview is available on our website!

Posted by: Markus | Tagged as: , , , , , No Comments
28Nov/160

NEW at Contabo: Fedora 25 and Suse Leap 42.2

From now on, we offer you Fedora in its latest version 25, it replaces the previous version 24. Likewise, Suse Leap received an update and the new version 42.2 is available now at Contabo!

Both operating systems can be combined with the Software RAID 1 and Webmin. In addition, Fedora 25 can be installed via VNC as well.

Existing customers can upgrade to the latest versions easily through the customer control panel.

We offer you a wide range of the latest Linux distributions (as well as Windows Server 2012 and 2016!). Simply click on "Customize & Order" below your desired (virtual) server model to get a detailed overview and select your OS of choice!

Further information and a product overview is available on our website!

Posted by: Markus | Tagged as: , , , , , , No Comments
8Sep/160

Comparison of the different Linux distributions available at Contabo

As a valued customer of Contabo you have access to a variety of different Linux distributions, for use on all of our servers. These can be easily and automatically installed via our powerful customer control panel, which results in various benefits for our customers:

- Contabo always provides the latest versions for installation on all servers.

- You can conveniently and comfortably choose and switch between the offered Linux distributions at any time.

- All Linux distributions are offered free of any costs or fees.

- From the beginner towards the enthusiast, up to commercial professional use, all requirements can be met with the distributions offered by Contabo.

CentOS:

CentOS (Community Enterprise Operating System) is a Linux distribution based on Red Hat Enterprise Linux (RHEL). It is maintained by an open group of voluntary developers, which take care of maintenance and development. As opposed to RHEL, you can use this operating system without mandatory support contracts and free of charge.

WHMs cPanel is developed for this operating system in particular, which makes this Linux distribution a must have for resellers. As an enterprise operating system it is developed with stability and long-term maintenance cycles in mind. All CentOS versions can be used for 10 years without the need to migrate packages and software versions, which makes it an ideal solution for commercial use.

https://www.centos.org/

Debian:

Debian is another Linux distribution that is composed completely of free software, most of which is under the GNU General Public License.

Long term support was first introduced with version 7 for almost all available software packages that use the architectures i386 and AMD64 (32bit- and 64bit-PC-systems). The Debian Project aims to provide 5 years long-term support with security and bug fixes for all versions from 7 upwards. This Linux distribution has access to online repositories that contain over 50,000 software packages, making it one of the largest software compilations available. Debian officially contains only free software, but non-free software can be downloaded and installed as well if needed. This makes it a valid solution for commercial use, as well as a versatile operating system for the regular user.

https://www.debian.org/

Ubuntu:

Ubuntu is a Linux distribution that is strongly based on and influenced by Debian. The goal of the developers was to create an operating system that is as easy to use as possible. It is one of the most commonly used distributions available today. The development team also releases long term support versions of Ubuntu, which are indicated by “LTS” at the end of the version number.

http://www.ubuntu.com/

OpenSUSE:

The focus of its development is creating usable open source tools for developers and administrators, while providing a user friendly desktop and server environment. A unique feature of this distribution is its specialized installation and configuration tool YaST (“Yet another Setup Tool“), which is a central administrative tool for the OpenSUSE operating system. It also helps finding new software and packages for the OpenSUSE distribution.

https://en.opensuse.org/Main_Page

Fedora:

Compared to other Linux distributions, Fedora does not aim for long term support. The life cycle of a Fedora version is 13 months only. Every 6 months a new version is released by the development team. Owing to this circumstance, Fedora is not suited for long-term usage on systems.

On the other hand, you have always access to the latest software developments available. Being state of the art has never been this comfortable. Enthusiasts that are eager to try out the latest developments on the market should always consider using Fedora.

https://getfedora.org/en/

Posted by: Philipp | Tagged as: , , , , , , No Comments
8Jul/161

Proxmox 4.0 and CentOS 7.2 available now!

We are happy to offer you further upgrades for our operating systems:

CentOS 7.2 is available now, replacing the version 7.1!
You may combine it with Software RAID 1, Webmin, LAMP, Webmin+LAMP, Plesk and cPanel. Plus, the installation via VNC is possible!

Also, Proxmox is available now in version 4.0, replacing 3.2. It is not an independent operating system but you may select it as a panel for Debian 8.

Please note: Proxmox is only available for our dedicated servers!

Proxmox4Proxmox 4

We offer you a wide range of Linux distributions (as well as Windows Server 2008/2012). Just click on "Customize & Order" on our VPS and dedicated servers overview sites and choose the operating system that fits your needs!

Further information can be found on our website!

Posted by: Markus | Tagged as: , , , , , 1 Comment
30Jun/160

New Operating Systems available: Fedora 24 and CentOS 6.8

Recently, two operating systems received an upgrade: Fedora is now available in version 24, replacing version 23. Also, CentOS 6.6 upgraded to 6.8. The latest versions are available at Contabo now!

Fedora 24 can be combined with Software RAID 1 and Webmin, the installation via VNC is possible!

You may combine CentOS 6.8 optionally with Software RAID 1, Webmin, LAMP, Webmin+LAMP, Plesk or cPanel - an installation via VNC is possible as well!

fedora24The basic panel of Fedora 24

Apart from Fedora 24 and CentOS 6.8, we do offer you a wide range of Linux distributions (as well as Windows Server 2008/2012). Just click on "Customize & Order" on our VPS and dedicated servers overview sites and opt for the operating system that fits your needs!

Further information can be found on our website!

24May/160

Changing the partition layout of your VPS after installation

Sometimes, it is necessary to change your partition layout in order to create new partitions or extend an existing partition, for example after a VPS upgrade.

This tutorial shows how to easily change your partition layout on your VPS.

Please be advised to perform a backup of all important data before proceeding ! Changes to the partition table always bear the risk of complete data loss.

Linux


Step 1:

Boot your VPS into the rescue-system, this can be done within your customer control panel.

You will need to connect through VNC.

After you have established a connection login as "root".

Step 2:

To perform changes on the partition easily we are going to use gparted.
To start the GUI type "startx" within your VNC console and wait a few seconds until the graphical interface appears.

On the upper left side you will see "Applications", open it and select "Run Program".
Now type "gparted" within the application finder and the app should start immediately.

part1

 

 

 

 

 

 

 

 

 

 

Step 3:

You should find an overview of all existing partitions on your hard disk drive.
In case there is no unused space left,  we need to shrink one existing partition first, otherwise we will not be able to create a new one.

After a right click on the corresponding partition and choosing "Resize/Move", the partition can be either shrunk or extended.

Please note that LVM partitions (which are used with CentOS by default) cannot be shrunk!

part3

In case you only wanted to extend your existing partition, please proceed with step 5.

Step 4:

Creating new partitions on the recently freed up/already free storage.

part4
Perform a right click on the unallocated space and select "new" to create a new partition.

In this case I did it twice to create two additional partitions.

part5

Step 5:

So far, no actual changes have been made on your hard drive. If you want to restart the partitioning just rerun the gparted tool.

To write the changes to the HDD hit the green tick symbol.
After hitting the tick, a warning will appear saying that you can lose all data - you should have a backup, so no worries.

 

part6

 

The application should start performing several tasks, just wait until it has finished.

Depending on the size of the partition and the data stored on it, this will take its time.

 

part7

 

Step 6:

You are done, just boot up your VPS into the regular OS  and check if everything is as expected:

root@contabo-test:~# fdisk -l

 

Windows


Step 1:

Connect to your server using RDP.

Step 2:

Open the "Disk Management", this can be done with a right click on the Windows Icon on the lower left side.
You could also start it by opening the "run" prompt, which can be done  via "Start" -> "Execute" -> "diskmgmt.msc", alternately the "Execute" dialogue can be opened by hitting "Windows-Logo-Key +R"

winp1_en
Step 3:

After the Windows "Disk Management" utility was started you will see an overview of all installed harddrives.
On a VPS you will usually have one drive, on a dedicated Server you will probably have more than one sparse disk.
Search for the disk you want to repartition and perform a right click on the partition you want to resize.

You can shrink and also extend a Volume, sometimes when upgrading your VPS to a bigger plan you can either create a second partition or just extend the existing partition.

For now we want to shrink the existing partition, so we hit "Shrink Volume".

winp2_en
Step 4:

After some time passed you will see a popup, just fill out the field with the amount of space you want to free up and hit "shrink".

winp3_en

After shrinking you will have unallocated space, now you are ready to create a new partition, e.g. a FAT32 filesystem etc.

winp4_en

Posted by: Gianni-Donato | Tagged as: , , , , , , , , No Comments