Password is widely used in a production environment, for example, when we created a system account, we need to set an initial password for it, and When email / database / Subversion / LDAP (..etc.) accounts created, random passwords are needed as well.

Debian uses a Sys-V like init system for executing commands when the system runlevel changes – for example at bootup and shutdown time. Its startup files are stored in /etc/init.d/ and symbolic linked within the /etc/rcX.d/ directories. Debian Linux comes with different utilities to manage these [...]

Facebook released a kernel module called Flashcache this wednesday, which is used to speed up MySQL by caching data in faster media like SSD disks.  It’s only tested for kernel versions 2.6.18 and 2.6.20.

By default OpenVZ is using VENET as network device. It does packet switching based on IP header, which makes it look like a point-to-point connection between VPS and the physical host. An alternative device is Virtual Ethernet device (a.k.a. VETH).

Yum is commonly used in major RPM based Linux distributions such as CentOS, Redhat and SuSE, it can help us perform automatic dependency checking. If you’d like to only download the RPM packages via yum and do not install/update them, it’s nearly impossible by default.

In this post we’ll show an example on how to implement transfer rate limitation in Nginx. As this limitation is User agent based, it can be very meaningful for high transfer volume websites like download site,  a mirror site like mirror.centos.org, etc.

Suppose you made a mistake on the Vserver name when creating it. After finished the installation, you might want to rename your Vserver. This can be accomplished by renaming the config directory and the root for the vserver in question, then modifying some symlinks to match.

I just successfully updated my Dell PowerEdge 1850 from CentOS 4.8 to CentOS 5.4, luckily the issues I faced were not so rare. The steps I used are listed below, may it helpful for you as well! Although this post is mainly intended for CentOS it should work on RHEL systems as well. Before you start, [...]

Warning – this post was original created by Jason Dixon some yrs ago, its copyright is fully held by samag.com. I copied it here for a track record, If there’s any issue, please let me know. As the pictures in this post had lost already,  it’s suggested to check its PDF version here. Firewalls [...]

Your computer has two timepieces; a battery-backed one that is always running (a.k.a. the hardware, BIOS, or CMOS clock), and another that is maintained by the operating system currently running, it’s called system clock. This document explains how to set your system clock, your timezone, and other [...]