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How to fix high CPU utilization in Linux web hosting servers

At one time or another every server owner faces high CPU utilization or CPU running at 100%.

It results in sluggish servers, unresponsive application and unhappy customers.

That’s why at Bobcares, we prevent downtime by monitoring and resolving such utilization issues as quickly as they come. (more…)

The right way to fix “The certificate is not trusted” error in Plesk

VPS or Dedicated server owners who use Plesk sometimes receive the error “The certificate is not trusted” when accessing the Plesk panel.

This is due to Plesk using a “self-signed” certificate – which means that the certificate is not an authentic CA certificate issued by a recognized authority like Verizon or Comodo.


How to fix “Error: xz compression not available” in CentOS and cPanel & WHM upgrade provides outsourced hosting support to web hosting companies. As part of our work, we help web hosting companies keep their servers upgraded and patched to the latest version.

In some cPanel/WHM and CentOS servers, we’ve faced the error Error: xz compression not available when performing a distribution upgrade. (more…)

How to fix libuser root privilege and DoS attack vulnerability

How to fix libuser root privilege and DoS attack vulnerability

Qualys reported on 23rd July an important root privilege escalation vulnerability (CVE-2015-3246), and DoS attack vulnerability (CVE-2015-3245) for Linux servers using RedHat’s libuser package. Here’s how you can protect your CentOS and RedHat server from these vulnerabilities. (more…)

Have a happy Upgrade

Linux has always been blessed. As we have a large number of people working for the betterment of the product, we’ll have bug fixes/security updates every now and then. This has got 2 sides.

  • The good part- if you keep on upgrading; you will have a more secure, bug-free product.
  • The bad part- if you never upgrade; the whole world knows the security vulnerabilities of the outdated version. I guess this could be as good as tweeting your root password.

So, we’ve got to update the systems as and when the updates arrive. But, an update once in a month will mean a reboot once a month, which will mean monthly server downtime. This is where Ksplice comes into the picture.


SELinux: For A Secure Web Space


Linux is a premium force in the web hosting industry, which is also achieving popularity as a PC operating system nowadays. When it comes to hosting a website, Linux web servers are primarily chosen due to their flexibility, stability and security of services. But as we all know, security of all operating systems revolve around controlling access and is hence subject to exploits. Since Linux is open source, vulnerabilities can be easily exploited by potential attackers to gain illegal access to a web server. As a measure of securing Linux at every level, from the kernel up, Security Enhanced Linux (SELinux) was developed.


R1soft and Buffalo Terastation- An Efficient and Easy-To-Use Backup System for Web Hosts

In every server farm, backup systems play a vital role in data retention and and recovery. When it comes to Linux, there are many open source backup solutions available. You can setup a well organized backup strategy using rsync, dd, tar, cpio etc, as per your requirement. But, these backups may turn out to be time consuming during restoration and do not provide good options for bare metal restoration. It is always better to go for a good interface through which we can restore data, quickly. In such a scenario, R1soft can be used as an optimal solution.

Usually, a backup server will be used to store the entire backup data. Server farms consists of several terabytes of data, which makes it quite difficult to manage them using a local storage. So normally NAS devices are chosen to ensure reliable backup operations. For such a setup, Buffalo Terastation Pro, which provides a very reliable and good management interface will be a good option.


Ext4 File System – Features and Setup

The fourth extended file system was developed as the successor of the commonly used ext3 journaled file system. The ext4 file system has significant advantages over the ext3 and ext2 file systems.

Support for the ext4 file system has been available from the Linux kernel version 2.6.19 onwards and was officially declared stable in the Linux kernel version 2.6.28. All the latest versions of distributions like Ubuntu (9.04), Fedora (11) etc. include the ext4 file system.


Udev:: Introduction to Device Management In Modern Linux System

Modern Linux distributions are capable of identifying a hardware component which is plugged into an already running system. There are a lot of user friendly distributions like Ubuntu, which will automatically run specific applications like Rhythmbox when a portable device like an Ipod is plugged into the system.


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Hotplugging (which is the word used to describe the process of inserting devices into a running system) is achieved in a Linux distribution by a combination of three components: Udev, HAL and Dbus.

Udev supplies a dynamic device directory containing only the nodes for devices which are connected to the system. It creates or removes the device node files in the /dev directory as they are plugged in or taken out. Dbus is like a system bus which is used for inter-process communication. The HAL gets information from the Udev service, when a device is attached to the system and it creates an XML representation of that device. It then notifies the corresponding desktop application like Nautilus through the Dbus and Nautilus will open the mounted device’s files.