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Posts published in “Linux”

Change Linux CentOS Ethernet Interface Name to Default eth0


Disable Consistent Interface Device Naming To regain the ethX back, edit the grub file. vi /etc/default/grub Look for GRUB_CMDLINE_LINUX and add or change to the following net.ifnames=0. FROM: GRUB_CMDLINE_LINUX="crashkernel=auto resume=/dev/mapper/cl-swap rhgb quiet" TO: GRUB_CMDLINE_LINUX="crashkernel=auto resume=/dev/mapper/cl-swap net.ifnames=0 rhgb quiet" [[email protected] ~]# ip addr show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft…

Linux CentOS/Ubuntu Firewall and SELinux


The Linux kernel includes the Netfilter subsystem, which is used to manipulate or decide the fate of network traffic headed into or through your server. All modern Linux firewall solutions use this system for packet filtering.

Security-Enhanced Linux (SELinux) is a Linux kernel security module that provides a mechanism for supporting access control security policies, including mandatory access controls (MAC). SELinux is a set of kernel modifications and user-space tools that have been added to various Linux distributions.

Linux System Performance Analytics


This post is going to use an java code example to show the process how to analysis linux system performance issue using all kinds of Linux internal commands without other third party tools. System: Top Here is a java code for an example top check system resource usage [[email protected] ~]# top top – 11:28:50 up 7 min, 2 users, load average: 0.73, 0.39, 0.18 Tasks: 230 total, 1 running, 229 sleeping, 0 stopped, 0 zombie…