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, 03 Feb 2012 22:45:35 +0000 en hourly 1 http://wordpress.org/?v=3.3.1 http://www.cyberciti.biz/tips/identifying-linux-bottlenecks-sar-graphs-with-ksar.html http://www.cyberciti.biz/tips/identifying-linux-bottlenecks-sar-graphs-with-ksar.html#comments Tue, 15 Dec 2009 06:33:21 +0000 Vivek Gite http://www.cyberciti.biz/tips/?p=6165 The sar command collect, report, or save UNIX / Linux system activity information. It will save selected counters in the operating system to the /var/log/sa/sadd file. From the collected data, you get lots of information about your server:

1. CPU utilization
2. Memory paging and its utilization
3. Network I/O, and transfer statistics
4. Process creation activity
5. All block devices activity
6. Interrupts/sec etc.

sar output can be used for identifying server bottlenecks. However, analyzing information provided by sar can be difficult, so use kSar, which can take sar output and plot a nice easy to understand graph over period of time. ]]> http://www.cyberciti.biz/tips/identifying-linux-bottlenecks-sar-graphs-with-ksar.html/feed 21 http://www.cyberciti.biz/tips/linux-security.html http://www.cyberciti.biz/tips/linux-security.html#comments Fri, 30 Oct 2009 07:52:11 +0000 Vivek Gite 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 102 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 Vivek Gite 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 265 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 Vivek Gite http://www.cyberciti.biz/tips/?p=4940 The ss command is used to dump socket statistics. 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.
• All the tcp sockets in state FIN-WAIT-1 and much more.

]]> http://www.cyberciti.biz/tips/linux-investigate-sockets-network-connections.html/feed 9 http://www.cyberciti.biz/tips/rhel-fedora-centos-debian-ubuntu-lighttpd-mod_rrdtool.html http://www.cyberciti.biz/tips/rhel-fedora-centos-debian-ubuntu-lighttpd-mod_rrdtool.html#comments Sat, 23 May 2009 09:53:22 +0000 Vivek Gite http://www.cyberciti.biz/tips/?p=4878 The round-robin database tool aims to handle time-series data like network bandwidth, temperatures, CPU load etc. The data gets stored in round-robin database so that system storage footprint remains constant over time. Lighttpd comes with mod_rrdtool to monitor the server load and other details. This is useful for debugging and tuning lighttpd / fastcgi server performance. ]]> http://www.cyberciti.biz/tips/rhel-fedora-centos-debian-ubuntu-lighttpd-mod_rrdtool.html/feed 8 http://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 Vivek Gite 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 12 http://www.cyberciti.biz/tips/vmware-esx-server-scsi-timeout-for-linux-guest.html http://www.cyberciti.biz/tips/vmware-esx-server-scsi-timeout-for-linux-guest.html#comments Sat, 17 Jan 2009 20:34:23 +0000 Vivek Gite /sys$DEVPATH/device/timeout'"]]> http://www.cyberciti.biz/tips/?p=5811 Recently, I noticed that the timeout values differ on CentOS v5.x and RHEL Linux 5.x guests on VMWare ESX4 and ESX3.5.]]> http://www.cyberciti.biz/tips/vmware-esx-server-scsi-timeout-for-linux-guest.html/feed 0 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 Vivek Gite 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/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 Vivek Gite 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/nagios-network-monitoring-server-monitoring.html http://www.cyberciti.biz/tips/nagios-network-monitoring-server-monitoring.html#comments Fri, 11 Jul 2008 09:42:24 +0000 Vivek Gite http://www.cyberciti.biz/tips/?p=2458 http://www.cyberciti.biz/tips/nagios-network-monitoring-server-monitoring.html/feed 6 http://www.cyberciti.biz/tips/wtop-web-server-log-monitoring-tool.html http://www.cyberciti.biz/tips/wtop-web-server-log-monitoring-tool.html#comments Tue, 17 Jun 2008 17:47:41 +0000 Vivek Gite http://www.cyberciti.biz/tips/?p=2373 http://www.cyberciti.biz/tips/wtop-web-server-log-monitoring-tool.html/feed 1 http://www.cyberciti.biz/tips/ubuntu-debian-linux-openssl-dsa-1571.html http://www.cyberciti.biz/tips/ubuntu-debian-linux-openssl-dsa-1571.html#comments Mon, 16 Jun 2008 10:09:53 +0000 Vivek Gite http://www.cyberciti.biz/tips/?p=2368 http://www.cyberciti.biz/tips/ubuntu-debian-linux-openssl-dsa-1571.html/feed 2 http://www.cyberciti.biz/tips/linux-display-open-ports-owner.html http://www.cyberciti.biz/tips/linux-display-open-ports-owner.html#comments Fri, 30 May 2008 11:57:08 +0000 Vivek Gite http://www.cyberciti.biz/tips/?p=2328 http://www.cyberciti.biz/tips/linux-display-open-ports-owner.html/feed 8 http://www.cyberciti.biz/tips/ktrace-freebsd-macosx-tool-howto.html http://www.cyberciti.biz/tips/ktrace-freebsd-macosx-tool-howto.html#comments Wed, 16 Apr 2008 18:31:33 +0000 Vivek Gite http://www.cyberciti.biz/tips/?p=2205 FreeBSD => OpenBSD => Mac OS X => NetBSD The ktrace utility enables kernel trace logging [...]]]> http://www.cyberciti.biz/tips/ktrace-freebsd-macosx-tool-howto.html/feed 2 http://www.cyberciti.biz/tips/load-balancer-open-source-software.html http://www.cyberciti.biz/tips/load-balancer-open-source-software.html#comments Tue, 11 Mar 2008 17:01:49 +0000 Vivek Gite http://www.cyberciti.biz/tips/load-balancer-open-source-software.html http://www.cyberciti.biz/tips/load-balancer-open-source-software.html/feed 12 http://www.cyberciti.biz/tips/netstat-command-tutorial-examples.html http://www.cyberciti.biz/tips/netstat-command-tutorial-examples.html#comments Thu, 21 Feb 2008 07:14:48 +0000 Vivek Gite http://www.cyberciti.biz/tips/netstat-command-tutorial-examples.html Explains how to use netstat command to display current connections and find out if your server is under DoS attack or not.]]> http://www.cyberciti.biz/tips/netstat-command-tutorial-examples.html/feed 16 http://www.cyberciti.biz/tips/freebsd-lists-open-internet-unix-domain-sockets.html http://www.cyberciti.biz/tips/freebsd-lists-open-internet-unix-domain-sockets.html#comments Fri, 08 Feb 2008 18:50:50 +0000 Vivek Gite http://www.cyberciti.biz/tips/freebsd-lists-open-internet-unix-domain-sockets.html http://www.cyberciti.biz/tips/freebsd-lists-open-internet-unix-domain-sockets.html/feed 0 http://www.cyberciti.biz/tips/tool-to-monitor-linux-system-call-latencies.html http://www.cyberciti.biz/tips/tool-to-monitor-linux-system-call-latencies.html#comments Sat, 19 Jan 2008 08:51:02 +0000 Vivek Gite http://www.cyberciti.biz/tips/tool-to-monitor-linux-system-call-latencies.html http://www.cyberciti.biz/tips/tool-to-monitor-linux-system-call-latencies.html/feed 0 http://www.cyberciti.biz/tips/nmap-hide-ipaddress-with-decoy-ideal-scan.html http://www.cyberciti.biz/tips/nmap-hide-ipaddress-with-decoy-ideal-scan.html#comments Tue, 08 Jan 2008 14:37:14 +0000 Vivek Gite http://www.cyberciti.biz/tips/nmap-hide-ipaddress-with-decoy-ideal-scan.html http://www.cyberciti.biz/tips/nmap-hide-ipaddress-with-decoy-ideal-scan.html/feed 3 http://www.cyberciti.biz/tips/display-disk-io-subsystem-total-statistics.html http://www.cyberciti.biz/tips/display-disk-io-subsystem-total-statistics.html#comments Fri, 04 Jan 2008 05:13:15 +0000 Vivek Gite http://www.cyberciti.biz/tips/display-disk-io-subsystem-total-statistics.html http://www.cyberciti.biz/tips/display-disk-io-subsystem-total-statistics.html/feed 0