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. Fri, 14 Jun 2013 21:36:33 +0000 en-US hourly 1 http://wordpress.org/?v=3.5.1 http://www.cyberciti.biz/tips/apple-mac-osx-find-and-remove-flashback-trojan-malware.html http://www.cyberciti.biz/tips/apple-mac-osx-find-and-remove-flashback-trojan-malware.html#comments Thu, 05 Apr 2012 15:07:44 +0000 nixCraft http://www.cyberciti.biz/tips/?p=8787 The Flashback Trojan, is a trojan horse affecting personal computer systems running Apple Mac OS X. More than half a million Apple computers have been infected with the Flashback Trojan.]]> http://www.cyberciti.biz/tips/apple-mac-osx-find-and-remove-flashback-trojan-malware.html/feed 14 http://www.cyberciti.biz/tips/linux-core-dumps.html http://www.cyberciti.biz/tips/linux-core-dumps.html#comments Thu, 03 Jun 2010 09:34:03 +0000 nixCraft /dev/null 2>&1]]> http://www.cyberciti.biz/tips/?p=7006 Core dumps are often used to diagnose or debug errors in Linux or UNIX programs. Core dumps can serve as useful debugging aids for sys admins to find out why Application like Lighttpd, Apache, PHP-CGI or any other program crashed. Many vendors and open source project author requests a core file to troubleshoot a program. A core file is generated when an application program abnormally terminates due to bug, operating system security protection schema, or program simply try to write beyond the area of memory it has allocated, and so on. This article explains how to turn on core file support and track down bugs in programs.]]> http://www.cyberciti.biz/tips/linux-core-dumps.html/feed 23 http://www.cyberciti.biz/tips/open-source-project-management-software.html http://www.cyberciti.biz/tips/open-source-project-management-software.html#comments Sun, 19 Jul 2009 19:18:10 +0000 nixCraft http://www.cyberciti.biz/tips/?p=5477 Project management software is not just for managing software based project. It can be used for variety of other tasks too. The web-based software must provide tools for planning, organizing and managing resources to achieve project goals and objectives. A web-based project management software can be accessed through an intranet or WAN / LAN using a web browser. You don't have to install any other software on the system. The software can be easy of use with access control features (multi-user). I use project management software for all of our projects (for e.g. building a new cluster farm) for issue / bug-tracking, calender, gantt charts, email notification and much more.

Obviously I'm not the only user, the following open source software is used by some of the biggest research organizations and companies world wild. For e.g. NASA's Jet Propulsion Laboratory uses track software or open source project such as lighttpd / phpbb use redmine software to keep track of their projects.]]> http://www.cyberciti.biz/tips/open-source-project-management-software.html/feed 85 http://www.cyberciti.biz/tips/website-load-speed-performace-testing-tools.html http://www.cyberciti.biz/tips/website-load-speed-performace-testing-tools.html#comments Wed, 15 Jul 2009 17:42:34 +0000 nixCraft http://www.cyberciti.biz/tips/?p=5346 Research shows that if your web pages take longer than 5 seconds to load, you lose 50% of your viewers and sales. As a UNIX admin often end users and web developers complain about website loading speed and timings. Usually, there is nothing wrong with my servers or server farm. Fancy java script and images / flash makes site pretty slow. These tools are useful to debug performance problems for sys admins, developers and end users. Here are six tools that can analyzes web pages and tells you why they are slow. Use the following tools to:

• Make your site faster.
• Debug site problem, especially client side and server side stuff.
• Better user experience.
• Improve the web.

]]> http://www.cyberciti.biz/tips/website-load-speed-performace-testing-tools.html/feed 25 http://www.cyberciti.biz/tips/top-linux-monitoring-tools.html http://www.cyberciti.biz/tips/top-linux-monitoring-tools.html#comments Sat, 27 Jun 2009 02:26:39 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4934 Need to monitor Linux server performance? Try these built-in command and a few add-on tools. Most Linux distributions are equipped with tons of monitoring. These tools provide metrics which can be used to get information about system activities. You can use these tools to find the possible causes of a performance problem. The commands discussed below are some of the most basic commands when it comes to system analysis and debugging server issues such as:

1. Finding out bottlenecks.
2. Disk (storage) bottlenecks.
3. CPU and memory bottlenecks.
4. Network bottlenecks.

]]> http://www.cyberciti.biz/tips/top-linux-monitoring-tools.html/feed 322 http://www.cyberciti.biz/tips/openofficeorg-new-user-orientation.html http://www.cyberciti.biz/tips/openofficeorg-new-user-orientation.html#comments Wed, 03 Jun 2009 11:26:39 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4967 OpenOffice.org (OOo) is a freely available, full-featured office suite. OOo is both a software product and a community of volunteers that produces and supports the software. However, new users may get lost while finding help, support and productivity enhancing extensions. This blog post covers OOo new user orientation to to discover support, tutorials, community insights, templates, clip art, extensions, and blogs for OOo. ]]> http://www.cyberciti.biz/tips/openofficeorg-new-user-orientation.html/feed 0 http://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 http://www.cyberciti.biz/tips/linux-investigate-sockets-network-connections.html http://www.cyberciti.biz/tips/linux-investigate-sockets-network-connections.html#comments Tue, 02 Jun 2009 12:56:31 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4940 The ss command is used to show socket statistics. It can display stats for PACKET sockets, TCP sockets, UDP sockets, DCCP sockets, RAW sockets, Unix domain sockets, and much more. It allows showing information similar to netstat command. It can display more TCP and state information than other tools. It is a new, incredibly useful and faster (as compare to netstat) tool for tracking TCP connections and sockets. SS can provide information about:

• All TCP sockets.
• All UDP sockets.
• All established ssh / ftp / http / https connections.
• All local processes connected to X server.
• Filtering by state (such as connected, synchronized, SYN-RECV, SYN-SENT,TIME-WAIT), addresses and ports.
• All the tcp sockets in state FIN-WAIT-1 and much more.

]]> http://www.cyberciti.biz/tips/linux-investigate-sockets-network-connections.html/feed 10 http://www.cyberciti.biz/tips/missing-memory.html http://www.cyberciti.biz/tips/missing-memory.html#comments Fri, 13 Mar 2009 18:53:20 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4518 Today, I've upgraded total 8 servers from 4GiB to 8GiB to improve performance of system by inserting additional memory modules. We started each server and checked for memory count at console. All severs booted normally after the upgrade and services such as SMTP, NFS, CIFS, HTTP started as expected. Shortly, afterwords I got a call from help desk about pop3 server for slow performance. ]]> http://www.cyberciti.biz/tips/missing-memory.html/feed 8 http://www.cyberciti.biz/tips/howto-upgrade-debian-linux-4etch-to-5lenny-server.html http://www.cyberciti.biz/tips/howto-upgrade-debian-linux-4etch-to-5lenny-server.html#comments Mon, 16 Feb 2009 17:20:43 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4442 Debian version 5.0 has been released. It is recommended that you upgrade the system to latest version. Upgrading remote Debian server is a piece of cake. In this tutorial, you will learn about upgrading Debian Linux server from Etch to Lenny over ssh session.]]> http://www.cyberciti.biz/tips/howto-upgrade-debian-linux-4etch-to-5lenny-server.html/feed 22 http://www.cyberciti.biz/tips/msglogerrorunrecoverable-vmware-remote-console-plug-in.html http://www.cyberciti.biz/tips/msglogerrorunrecoverable-vmware-remote-console-plug-in.html#comments Mon, 26 Jan 2009 20:43:31 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4374 I'm having some weird problem with Firefox 3.0.4 under Ubuntu Linux. My test server runs inside VMWare server version 2.0. It was working fine with my Laptop. But with my desktop it started to dump errors for me. when I try to open the console of a virtual machine I have following error:]]> http://www.cyberciti.biz/tips/msglogerrorunrecoverable-vmware-remote-console-plug-in.html/feed 2 http://www.cyberciti.biz/tips/linux-convert-ext3-to-ext4-file-system.html http://www.cyberciti.biz/tips/linux-convert-ext3-to-ext4-file-system.html#comments Fri, 23 Jan 2009 15:45:57 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4348 Some time ago ext4 was released and available for Linux kernel. ext4 provides some additional benefits and perforce over ext3 file system. You can easily convert ext3 to ext4 file system. The next release of Fedora, 11, will default to the ext4 file system unless serious regressions are seen. In this quick tutorial you will learn about converting ext3 to ext4 file system.]]> http://www.cyberciti.biz/tips/linux-convert-ext3-to-ext4-file-system.html/feed 19 http://www.cyberciti.biz/tips/bind-named-set-zone-transfer-ip-address.html http://www.cyberciti.biz/tips/bind-named-set-zone-transfer-ip-address.html#comments Thu, 08 Jan 2009 20:08:01 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4277 I've three nameserver load-balanced (LB) in three geo locations. Each LB has a front end public IP address and two backend IP address (one for BIND and another for zone transfer) are assigned to actual bind 9 server running Linux. So when a zone transfer initiates from slave server, all I get errors. A connection cannot be established, it tries again with the servers main ip or LB2 / LB3 ip. This is a problem because my servers are geo located and load balanced. However, there is a small workaround for this problem.]]> http://www.cyberciti.biz/tips/bind-named-set-zone-transfer-ip-address.html/feed 4 http://www.cyberciti.biz/tips/freebsd-process-accounting-tutorial.html http://www.cyberciti.biz/tips/freebsd-process-accounting-tutorial.html#comments Thu, 08 Jan 2009 10:00:08 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4259 I've already written about Linux process accounting under Linux ( see how to keep a detailed audit trail of what's being done on your Linux systems). You can easily setup process accounting under FreeBSD. This tutorial expalins how to enable and utilizing FreeBSD process accounting including many other useful options are explained to keep track of system resources used, and their allocation among users.]]> http://www.cyberciti.biz/tips/freebsd-process-accounting-tutorial.html/feed 1 http://www.cyberciti.biz/tips/rhel-fedora-centos-apache2-external-php-spawn.html http://www.cyberciti.biz/tips/rhel-fedora-centos-apache2-external-php-spawn.html#comments Tue, 30 Dec 2008 12:49:34 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4182 Now, mod_fastcgi is configured and running. FastCGI supports connection via UNIX sockets or TCP/IP networking. This is useful to spread load among various backends. For example, php will be severed from 192.168.1.10 and python / ruby on rails will be severed from 192.168.1.11. This is only possible with mod_fastcgi. ]]> http://www.cyberciti.biz/tips/rhel-fedora-centos-apache2-external-php-spawn.html/feed 8 http://www.cyberciti.biz/tips/test-and-troubleshoot-chrooted-apache-jail.html http://www.cyberciti.biz/tips/test-and-troubleshoot-chrooted-apache-jail.html#comments Mon, 22 Dec 2008 13:30:36 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4085 This is 3rd and the final installment for Apache Chroot Jail for CentOS / RHEL series. Once Apache is configured with mod_chroot, you may need to test and debug problems. This article will provide a few troubleshooting tips.]]> http://www.cyberciti.biz/tips/test-and-troubleshoot-chrooted-apache-jail.html/feed 0 http://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 57 http://www.cyberciti.biz/tips/authenticate-linux-clients-with-active-directory.html http://www.cyberciti.biz/tips/authenticate-linux-clients-with-active-directory.html#comments Tue, 18 Nov 2008 08:22:16 +0000 nixCraft http://www.cyberciti.biz/tips/?p=3576 Every IT shop has a mix of Windows and Linux system. Sometime you need to authenticate your Linux desktop system against Microsoft Active Directory service. You can save time, effort and IT infrastructure by sharing authentication server. This article explains how to setup the Linux desktop computers with Active Directory using Samba and winbind.]]> http://www.cyberciti.biz/tips/authenticate-linux-clients-with-active-directory.html/feed 6 http://www.cyberciti.biz/tips/book-review-nagios-system-network-monitoring.html http://www.cyberciti.biz/tips/book-review-nagios-system-network-monitoring.html#comments Sat, 18 Oct 2008 13:59:12 +0000 nixCraft http://www.cyberciti.biz/tips/?p=3102 The convenience and reliability that monitoring programs offer system administrators is astounding. Whether at home, commuting, or on vacation, admins can continuously monitor their networks, learning of issues long before they become catastrophes.
Nagios, the most popular open source solution for system and network monitoring, is extremely robust, but it's also intensely complex. ]]> http://www.cyberciti.biz/tips/book-review-nagios-system-network-monitoring.html/feed 3 http://www.cyberciti.biz/tips/linux-unix-lighttpd-ipv6-support.html http://www.cyberciti.biz/tips/linux-unix-lighttpd-ipv6-support.html#comments Fri, 03 Oct 2008 20:30:32 +0000 nixCraft http://www.cyberciti.biz/tips/?p=3014 Lighttpd supports both IPv6 and IPv4 protocol out of box. You need to compile lighttpd with IPv6 support. This small how to explains how to enable both IPv6 and IPv4 support under GNU/Linux / UNIX and FreeBSD operating systems.]]> http://www.cyberciti.biz/tips/linux-unix-lighttpd-ipv6-support.html/feed 4