How to Simplify Working With Kernels

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What Is A Kernel?

The kernel is a piece of software that is at the core of an operating system. It usually has complete control over all of the server systems. It is normally the first program loaded after the bootloader has completed its tasks. The kernel then handles the rest of the start-up tasks as well as i/o requests from the system’s software. It then translates those requests into hardware instructions for the CPU (central processing unit).

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How To Install nftables In Ubuntu

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firewall2-image

In this article, we will learn how to switch a Linux firewall from IPtables to nftables on Ubuntu. IPtables, which is based on the Linux kernel Netfilter module, is currently the default firewall for many Linux distributions. It protects against multiple threat vectors and allows your server to block unwanted traffic based on a specific ruleset.

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How To Check the Kernel Version in Linux / Ubuntu / CentOS

Reading Time: 2 minutesIn this article and related video, we will be discussing how to check the kernel version in both Ubuntu and CentOS Linux. The following command works with all Linux distributions, such as Red Hat, CentOS, Debian, and Ubuntu. It also works on other UNIX-like operating systems such as HPUX, FreeBSD, OpenBSD, Solaris, etc. Use the following command to check which kernel version your server is currently running:
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How Do I Secure My Linux Server?

Reading Time: 6 minutesOur last article on Ubuntu security suggestions touched on the importance of passwords, user roles, console security, and firewalls. We continue with our last article and while the recommendations below are not unique to Ubuntu specifically (nearly all discussed are considered best practice for any Linux server) but they should be an important consideration in securing your server. Continue reading “How Do I Secure My Linux Server?”

How to Upgrade Ubuntu 16.04 to Ubuntu 18.04

Reading Time: 6 minutesIf you are still using Ubuntu version 16.04, you may want to consider updating to the latest Long Term Support release, version 18.04. In this post, we will cover what a Long Term Support release is and why you would want to use it. You will also learn the significant changes between 16.04 and 18.04. Last, but not least, you will also learn how to upgrade your server from Ubuntu 16.04 to Ubuntu 18.04.

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How KernelCare Protects Your Server

Reading Time: 2 minutesOne of the most important things you can do to ensure the security and stability of your Linux server is to keep the kernel updated. Some Kernel updates patch security vulnerabilities and other issues. Kernel patches are released as issues are discovered.

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What Is KernelCare?

Reading Time: 2 minutesTux the Penguin with Hotpatching (KernelCare)The concept of ‘Kernel hotpatching’, sometimes called live patching, was introduced to the Linux community around 2008. Soon after groups began developing differing implementations of the concept. KernelCare, one of the more popular implementations, was originally released in March 2014 by Cloud Linux, Inc. Continue reading “What Is KernelCare?”

CVE-2015-0235 Vulnerability Info for Red Hat and CentOS

Reading Time: < 1 minuteA vulnerability found in the glibc library, specifically a flaw affecting the gethostbyname() and gethostbyname2() function calls, that allows a remote attacker to potentially execute arbitrary code. CentOS 5, CentOS 6, and CentOS 7 are potentially affected, thus we want to highlight the following information.

Liquid Web package repositories have been updated. Many servers (barring those with updates disabled) have received an update that patches this vulnerability, however, a reboot will still be required in those cases.

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CVE-2014-9322 Vulnerability Info for Red Hat and CentOS

Reading Time: < 1 minuteA vulnerability found in the Linux kernel, specifically a flaw in fault handling associated with the Stack Segment (SS), allows an unprivileged user to potentially gain privileges. CentOS 4, CentOS 5, CentOS 6, and CentOS 7 are potentially affected, thus we want to highlight the following information.
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Upgrade Core Managed Ubuntu 12.04 HWE Kernel

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It is highly recommended that you take an image of your existing server prior to following these instructions. Doing so will ensure that if something unexpected occurs, you will be able to restore your server from the backup image.

For instructions on creating a backup image from the Manage interface please visit:
https://www.liquidweb.com/kb/creating-storm-server-images/
https://www.liquidweb.com/kb/restoring-a-storm-server-from-an-image/

Pre-Flight Check
  • As of August 08, 2014, certain versions of Ubuntu 12.04 will no longer receive software updates for the kernel. Affected versions include: 12.04.2 HWE, 12.04.3 HWE, and 12.04.4 HWE.
  • These instructions are intended specifically and only for updating the kernel in Ubuntu 12.04 in Liquid Web US Central Zone B.
  • I’ll be working from a Liquid Web Core Managed Ubuntu 12.04 server, and I’ll be logged in as root.

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