nixCraft » Gentoo Linux http://www.cyberciti.biz/tips This is a Linux sys admin journal by Vivek about sys admin work, Linux tips & tricks, hacks, news and more. Wed, 24 Apr 2013 18:50:55 +0000 en-US hourly 1 http://wordpress.org/?v=3.5.1 Linux / Windows Application For Prevention Of RSI (Repetitive Strain Injury)http://www.cyberciti.biz/tips/repetitive-strain-injury-prevention-software.html http://www.cyberciti.biz/tips/repetitive-strain-injury-prevention-software.html#comments Wed, 04 Nov 2009 05:21:00 +0000 nixCraft http://www.cyberciti.biz/tips/?p=5950 workrave-image Repetitive strain injury (RSI) is occupational overuse syndrome, non-specific arm pain or work related upper limb disorder. RSI caused from overusing the hands to perform a repetitive task, such as typing, writing, or clicking a mouse. Unfortunately, most people do not understand what RSI is or how serious it can be. You can easily prevent RSI using open source software called Workrave.]]> http://www.cyberciti.biz/tips/repetitive-strain-injury-prevention-software.html/feed 14 20 Linux Server Hardening Security Tipshttp://www.cyberciti.biz/tips/linux-security.html http://www.cyberciti.biz/tips/linux-security.html#comments Fri, 30 Oct 2009 07:52:11 +0000 nixCraft http://www.cyberciti.biz/tips/?p=5687 Securing your Linux server is important to protect your data, intellectual property, and time, from the hands of crackers (hackers). The system administrator is responsible for security Linux box. In this first part of a Linux server security series, I will provide 20 hardening tips for default installation of Linux system.]]> http://www.cyberciti.biz/tips/linux-security.html/feed 116 Top 20 OpenSSH Server Best Security Practiceshttp://www.cyberciti.biz/tips/linux-unix-bsd-openssh-server-best-practices.html http://www.cyberciti.biz/tips/linux-unix-bsd-openssh-server-best-practices.html#comments Fri, 24 Jul 2009 21:49:43 +0000 nixCraft http://www.cyberciti.biz/tips/?p=5489 Don't tell anyone that I'm free OpenSSH is the implementation of the SSH protocol. OpenSSH is recommended for remote login, making backups, remote file transfer via scp or sftp, and much more. SSH is perfect to keep confidentiality and integrity for data exchanged between two networks and systems. However, the main advantage is server authentication, through the use of public key cryptography. From time to time there are rumors about OpenSSH zero day exploit. Here are a few things you need to tweak in order to improve OpenSSH server security.]]> http://www.cyberciti.biz/tips/linux-unix-bsd-openssh-server-best-practices.html/feed 134 Linux Find Out If PCI Hardware Supported or Not In The Current Running Kernelhttp://www.cyberciti.biz/tips/linux-find-supported-pci-hardware-drivers.html http://www.cyberciti.biz/tips/linux-find-supported-pci-hardware-drivers.html#comments Wed, 03 Jun 2009 15:05:04 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4971 From my mailbag:
How do I find out if a given PCI hardware is supported of by the current CentOS / Debian / RHEL / Fedora Linux kernel?
You can easily find out find out if a given piece of PCI hardware such as RAID, network, sound, graphics card is supported or not by the current Linux kernel using the following utilities under any Linux distributions.]]> http://www.cyberciti.biz/tips/linux-find-supported-pci-hardware-drivers.html/feed 10 Linux x86_64: Detecting Hardware Errorshttp://www.cyberciti.biz/tips/linux-server-predicting-hardware-failure.html http://www.cyberciti.biz/tips/linux-server-predicting-hardware-failure.html#comments Tue, 02 Jun 2009 21:54:58 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4951 The Blue Screen of Death (BSoD) is used for the error screen displayed by Microsoft Windows, after encountering a critical system. Linux / UNIX like operating system may get a kernel panic. It is just like BSoD. The BSoD and a kernel panic generated using a Machine Check Exception (MCE). MCE is nothing but feature of AMD / Intel 64 bit systems which is used to detect an unrecoverable hardware problem.

Program such mcelog decodes machine check events (hardware errors) on x86-64 machines running a 64-bit Linux kernel. It should be run regularly as a cron job on any x86-64 Linux system. This is useful for predicting server hardware failure before actual server crash.]]> http://www.cyberciti.biz/tips/linux-server-predicting-hardware-failure.html/feed 7 Linux Kernel Security (SELinux vs AppArmor vs Grsecurity)http://www.cyberciti.biz/tips/selinux-vs-apparmor-vs-grsecurity.html http://www.cyberciti.biz/tips/selinux-vs-apparmor-vs-grsecurity.html#comments Wed, 27 May 2009 22:29:17 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4903 Linux kernel is the central component of Linux operating systems. It is responsible for managing the system's resources, the communication between hardware and software and security. Kernel play a critical role in supporting security at higher levels. Unfortunately, stock kernel is not secured out of box. There are some important Linux kernel patches to secure your box. They differ significantly in how they are administered and how they integrate into the system. They also allow for easy control of access between processes and objects, processes and other processes, and objects and other objects. The following pros and cons list is based upon my personal experience. ]]> http://www.cyberciti.biz/tips/selinux-vs-apparmor-vs-grsecurity.html/feed 18 Lighttpd Install mod_geoip For Country / City Level Geo Targetinghttp://www.cyberciti.biz/tips/linux-lighttpd-install-mod_geoip-tutorial.html http://www.cyberciti.biz/tips/linux-lighttpd-install-mod_geoip-tutorial.html#comments Sun, 29 Mar 2009 04:35:28 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4567 Geolocation software is used to get the geographic location of visitor using IP address. You can determine country, organization and guess visitors location. This is useful for:

a] Fraud detection.

b] Geo marketing and ad serving.

c] Target content.

d] Spam fighting.

e] And much more.

mod_geoip is a Lighttpd module for fast ip/location lookups. In this tutorial you will learn about mod_geoip installation and php server side examples to determine visitors country. ]]> http://www.cyberciti.biz/tips/linux-lighttpd-install-mod_geoip-tutorial.html/feed 10 Security Through Obscurity: MAC Address Filtering ( Layer 2 Filtering )http://www.cyberciti.biz/tips/linux-unix-bsd-mac-filtering.html http://www.cyberciti.biz/tips/linux-unix-bsd-mac-filtering.html#comments Tue, 17 Feb 2009 18:37:21 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4452 MAC Filtering (layer 2 address filtering) refers to a security access control methodology whereby the 48-bit address assigned to each network card is used to determine access to the network. Iptables, pf, and IPFW can block a certain MAC address on a network, just like an IP. One can deny or allow from MAC address like 00:1e:2a:47:42:8d using open source firewalls. MAC address filtering is often used to secure LAN or wireless network / devices. Is this technique effective? ]]> http://www.cyberciti.biz/tips/linux-unix-bsd-mac-filtering.html/feed 14 How To Tail (View) Multiple Files on UNIX / Linux Consolehttp://www.cyberciti.biz/tips/multitail-view-multiple-files-like-tail-command.html http://www.cyberciti.biz/tips/multitail-view-multiple-files-like-tail-command.html#comments Mon, 09 Feb 2009 19:28:32 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4399 tail is one of the best tool to view log files in a real time (tail -f /path/to/log.file). The program MultiTail lets you view one or multiple files like the original tail program. The difference is that it creates multiple windows on your console (with ncurses). This is one of those dream come true program for UNIX sys admin job. You can browse through several log files at once and do various operations like search for errors and much more.]]> http://www.cyberciti.biz/tips/multitail-view-multiple-files-like-tail-command.html/feed 13 XEN Virtualization Set The MTU For xenbr0 Interfacehttp://www.cyberciti.biz/tips/fedora-debian-rhel-centos-linux-xen-setmtu-xenbr0.html http://www.cyberciti.biz/tips/fedora-debian-rhel-centos-linux-xen-setmtu-xenbr0.html#comments Wed, 31 Dec 2008 18:40:08 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4238 I've already written about setting the MTU (Maximum Transmission Unit) under Linux including Jumbo frames (FreeBSD specific MTU information is here).

With this quick tip you can increase MTU size to get a better networking performance.]]> http://www.cyberciti.biz/tips/fedora-debian-rhel-centos-linux-xen-setmtu-xenbr0.html/feed 0 BASH Shell: For Loop File Names With Spaceshttp://www.cyberciti.biz/tips/handling-filenames-with-spaces-in-bash.html http://www.cyberciti.biz/tips/handling-filenames-with-spaces-in-bash.html#comments Tue, 09 Dec 2008 19:18:29 +0000 nixCraft http://www.cyberciti.biz/tips/?p=3878 BASH for loop works nicely under UNIX / Linux / Windows and OS X while working on set of files. However, if you try to process a for loop on file name with spaces in them you are going to have some problem. for loop uses $IFS variable to determine what the field separators are. By default $IFS is set to the space character. There are multiple solutions to this problem.]]> http://www.cyberciti.biz/tips/handling-filenames-with-spaces-in-bash.html/feed 56 Linux: Boot a 2TB+ partition or Larger Array Using Grubhttp://www.cyberciti.biz/tips/howto-linux-boot-2tb-larger-raidarray-harddisk.html http://www.cyberciti.biz/tips/howto-linux-boot-2tb-larger-raidarray-harddisk.html#comments Thu, 04 Dec 2008 07:13:58 +0000 nixCraft http://www.cyberciti.biz/tips/?p=3718 I've already written about creating a partition size larger than 2TB under Linux using GNU parted command with GPT. In this tutorial, I will provide instructions for booting to a flat 2TB or larger RAID array under Linux using the GRUB boot loader.]]> http://www.cyberciti.biz/tips/howto-linux-boot-2tb-larger-raidarray-harddisk.html/feed 3 fold: Wrap Text File / Line / Words To Fit in Specified Widthhttp://www.cyberciti.biz/tips/linux-unix-word-wrap-command.html http://www.cyberciti.biz/tips/linux-unix-word-wrap-command.html#comments Tue, 25 Nov 2008 11:42:21 +0000 nixCraft http://www.cyberciti.biz/tips/?p=3649 fold is really nifty command line utility to make a text file word wrap. This is useful for large number of text files processing. There is no need to write a perl / python code or use a word processor. ]]> http://www.cyberciti.biz/tips/linux-unix-word-wrap-command.html/feed 2 Linux: Should You Use Twice the Amount of Ram as Swap Space?http://www.cyberciti.biz/tips/linux-swap-space.html http://www.cyberciti.biz/tips/linux-swap-space.html#comments Wed, 19 Nov 2008 08:50:49 +0000 nixCraft http://www.cyberciti.biz/tips/?p=3586 Linux and other Unix-like operating systems use the term "swap" to describe both the act of moving memory pages between RAM and disk, and the region of a disk the pages are stored on. It is common to use a whole partition of a hard disk for swapping. However, with the 2.6 Linux kernel, swap files are just as fast as swap partitions. Now, many admins (both Windows and Linux/UNIX) follow an old rule of thumb that your swap partition should be twice the size of your main system RAM. Let us say I've 32GB RAM, should I set swap space to 64 GB? Is 64 GB of swap space really required? How big should your Linux / UNIX swap space be? ]]> http://www.cyberciti.biz/tips/linux-swap-space.html/feed 64 Linux / UNIX: Find Out If a Directory Exists or Nothttp://www.cyberciti.biz/tips/find-out-if-directory-exists.html http://www.cyberciti.biz/tips/find-out-if-directory-exists.html#comments Sun, 16 Nov 2008 17:13:15 +0000 nixCraft http://www.cyberciti.biz/tips/?p=3560 I've already written a small tutorial about finding out if a file exists or not under Linux / UNIX bash shell. However, couple of our regular readers like to know more about a directory checking using if and test shell command. ]]> http://www.cyberciti.biz/tips/find-out-if-directory-exists.html/feed 4 Download Of The Day: GIMP 2.6 For Linux / Windows / Mac OS Xhttp://www.cyberciti.biz/tips/download-gimp-26.html http://www.cyberciti.biz/tips/download-gimp-26.html#comments Wed, 01 Oct 2008 20:30:27 +0000 nixCraft http://www.cyberciti.biz/tips/?p=3008 GIMP version 2.6 has been released and available for download. It is a free raster graphics editor used to manipulate digital graphics and photographs under Linux and other operating systems. It is often used as a free software replacement for Adobe Photoshop, the most widely used bitmap editor.]]> http://www.cyberciti.biz/tips/download-gimp-26.html/feed 2 Gnome Desktop Tip: Quickly Open Any File / URL / Write Emailhttp://www.cyberciti.biz/tips/gnome-open-file-using-prefeered-application.html http://www.cyberciti.biz/tips/gnome-open-file-using-prefeered-application.html#comments Fri, 22 Aug 2008 09:20:38 +0000 nixCraft http://www.cyberciti.biz/tips/?p=2698 There are three ways to open any file under Gnome Linux / UNIX Desktop. gnome-open is the quickest and easiest way to open any file or url. ]]> http://www.cyberciti.biz/tips/gnome-open-file-using-prefeered-application.html/feed 6 Linux / UNIX: Geany Lightweight Integrated Development Environmenthttp://www.cyberciti.biz/tips/linux-unix-geany-lightweight-code-editing-ide.html http://www.cyberciti.biz/tips/linux-unix-geany-lightweight-code-editing-ide.html#comments Wed, 09 Jul 2008 10:34:31 +0000 nixCraft http://www.cyberciti.biz/tips/?p=2455 http://www.cyberciti.biz/tips/linux-unix-geany-lightweight-code-editing-ide.html/feed 1 Download TrueCrypt Open Source Full Disk Encryption Softwarehttp://www.cyberciti.biz/tips/download-truecrypt-open-source-full-disk-encryption-software.html http://www.cyberciti.biz/tips/download-truecrypt-open-source-full-disk-encryption-software.html#comments Tue, 08 Jul 2008 13:29:34 +0000 nixCraft http://www.cyberciti.biz/tips/?p=2446 http://www.cyberciti.biz/tips/download-truecrypt-open-source-full-disk-encryption-software.html/feed 1 Linux Configure Netconsole To Log Messages Over UDP Networkhttp://www.cyberciti.biz/tips/linux-netconsole-log-management-tutorial.html http://www.cyberciti.biz/tips/linux-netconsole-log-management-tutorial.html#comments Wed, 02 Jul 2008 10:43:23 +0000 nixCraft http://www.cyberciti.biz/tips/?p=2431 http://www.cyberciti.biz/tips/linux-netconsole-log-management-tutorial.html/feed 4