“ViCompress HTTP proxy server reduces download time by gzip compressing text pages before sending them on the client. This results in faster download times, especially over slow network connections. ViCompress works with existing web servers and web browsers. All modern browsers (Internet Explorer, Firefox, Safari, Chrome) recognize gzip-encoded data, and will automatically decompress the data on the f...

For mysql, the system administrator user is called root. We will use the mysqladmin utility from a command line to set the new password. Default password is not secured at all. By default in RedHat, Fedora and Centos default password is null. So it is always better to set root password. To set root password, # mysqladmin -u root password XyZ@aBc@123 # mysqladmin -u root -h ...

There are various methods to run multiple instances of mysql (on different ports) on the same machine. Here I have used the same binary and used a separate configuration file (with separate port, pid, socket and data directory). We need to create new directories for our datadir and log folder (if used). Also we need to assign proper permissions on those folders: # mkdir /var/lib/mysql2 # chown -R mysql.mysql...

Google has recently released their very own DNS resolver with main goals of making web browsing faster and safer. Since Google's search engine already crawls the web on a daily basis and in the process resolves and caches DNS information, they wanted to make use of their technology to experiment with new ways of addressing some of the existing DNS challenges around performance and security. For advanced...

memtester is a user-space utility for testing the memory subsystem in a computer to determine if it is faulty. It does a good job of finding intermittent faults and non-deterministic faults. It has many tests to help catch borderline memory. memtester should compile and run on any 32- or 64-bit Unix or Unix-like system. Download latest version of memtester from...

When your system is rebooted, grub presents the boot option menu called splace screen. From here, you or anybody can easily login into a single user mode (sometimes it is called Rescue Mode) without the password which might result into breaching computer security. You can set a password for the GRUB boot loader. This prevents users from rescue or Singe-User  mode or changing settings at boot ...

Nginx quickly delivers static content with efficient use of system resources. It can deploy dynamic HTTP content on a network using FastCGI handlers for scripts, and can serve as a very capable software load balancer. Nginx uses an asynchronous event-driven approach to handling requests which provides more predictable performance under load, in contrast to the Apache HTTP server model that uses a threaded or...

We can configure apache – httpd service to listen Multiple ports via Listen directive. By default httpd listens on TCP port 80. To configure multiple ports, open file /etc/httpd/conf/httpd.conf and modify the Listen directive tells the server to accept incoming requests on the specified port # vi /etc/httpd/conf/httpd.conf Find, Listen 80 Force apache to listen to port 8...

MAC stands for Media Access Control and in a sense the MAC address is a computer's true name on a LAN. An Ethernet MAC address is a six byte number, usually expressed as a twelve digit hexadecimal number. To change this setting, we’ll need to edit the /etc/network/interfaces file. You can choose to use a different editor if you’d like. $ sudo gedit /etc/network/interfaces You s...

The mysqldump client is a backup program originally written by Igor Romanenko. It can be used to dump a database or a collection of databases for backup or transfer to another SQL server (not necessarily a MySQL server). The dump typically contains SQL statements to create the table, populate it, or both. However, mysqldump can also be used to generate files in CSV, other delimited text, or XML...

Reading or accessing NTFS partitions in Linux is important for many reasons. NTFS-3G is an open source cross-platform implementation of the Microsoft Windows NTFS file system with read-write support. NTFS-3G often uses the FUSE file system interface, so it can run unmodified on many different operating systems.  Before we start, make sure that you have rpmforge repository configured. If you do not have,...

In computer science, Memory Leakage occurs when a computer software or program consumes required memory but unable to memory after completing its task or when no longer needed to Operating System. There are two types of Memory Leakage. One is Virtual Memory Leakage and another is Real Memory Leakage. Now first Identify cached memory or unused memory by executing, ...

  This article will guide you through the necessary steps to install ipw3945 wireless adapter on a CentOS / RHEL based distribution. Before we start, make sure that you have rpmforge repository configured. If you do not have, download it from here. # wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el5.rf.i386.rpm # rpm -ivh...

Every time I connect to Linux server, I receive the same message and I’m getting tired of seeing it, so I decided to change the message to something else. Here’s the message that I get every time: [root@server1 ~]# ssh linuxarticles.org root@linuxarticles.org's password: Last login: Mon Oct 11 18:58:43 2010 from loc...

Squid is a proxy server and web cache daemon. It has a wide variety of uses, from speeding up a web server by caching repeated requests; to caching web, DNS and other computer network lookups for a group of people sharing network resources; to aiding security by filtering traffic.  Once after you have configured Squid, you may notice at the bottom of error page signature appears with GMT timezone. You might...

You can convert DEB file to RPM package and RPM to DEB package using alien command, if you have a *.rpm file that you want to install on a Debian or Ubuntu. Convert RPM to DEB Install alien command on Ubuntu as mentioned here: # sudo apt-get install alien Now, use alien command to convert rpm to deb file, # alien...

Sometimes you may get old web results and old webpages even after updating the web pages. That means, DNS cache holds the problem. To solve this problem, execute below command to flush DNS cache.  # /etc/rc.d/init.d/nscd restart

For mysql, the system administrator user is called root. We will use the mysqladmin utility from a command line to set the new password. Default password is not secured at all. By default in RedHat, Fedora and Centos default password is null. So it is always better to set root password. To re-set root password, first stop mysql service. # service mysqld stop # mysqld_safe...

As you login as “root” right from booting the system, all the privileges are set to root, what makes your system more vulnerable to your own mistakes and those wishing to enter your system. As you login as normal user, the privileges are limited, thus it´s safer. To be able to do administrative tasks you can temporally login as root using “su” in a console/terminal, that way the root privileges ...

vm.swappiness is a tunable kernel parameter that controls how much the kernel favors swap over RAM. At the source code level, it’s also defined as the tendency to steal mapped memory. A high swappiness value means that the kernel will be more apt to unmap mapped pages. A low swappiness value means the opposite, the kernel will be less apt to unmap mapped pages. In other words, the higher the v...

YUM is an interactive, rpm based, package manager. It can automatically perform system updates, including dependency analysis and obsolete processing based on "repository" metadata. It can also perform installation of new packages, removal of old packages and perform queries on the installed and/or available packages among many other commands/services (see below). yum is similar to other high level package ...

Linux kernel has PC speaker bell driver called pcspkr.ko. It is responsible for generating beeps while users are working on Shell Prompts ( Both Virtual and GUI Terminals ). If you don't like it, simply remove driver from kernel. Login as a root and type the following command to unload the driver: # rmmod -v pcspkr Sample output: rmmod pcspkr, wait=no We...

Single-User mode is used for a system recovery. However, by default, no authentication is used if single-user mode is selected. This can be used to bypassing security on the server and gaining root access. To enable authentication for single-user mode, open the /etc/inittab, file: # vi /etc/inittab Add the following line to the...

hdparm provides  a command line interface to various kernel interfaces supported by the Linux SATA/PATA/SAS "libata" subsystem and  the  older IDE driver subsystem.  Many newer (2008 and later) USB drive enclosures now also support "SAT" (SCSI-ATA Command Translation) and therefore may also  work  with  hdparm. To see how your hard disk does compare: # hdparm -t...

In computer terminology, a honeypot is a trap set to detect, deflect, or in some manner counteract attempts at unauthorized use of information systems. Generally it consists of a computer, data, or a network site that appears to be part of a network, but is actually isolated, (un)protected, and monitored, and which seems to contain information or a resource of value to attackers. STEP 1:...