The Boot Process From the moment a user turns on a Mac OS X system to beyond the time the login window appears, Mac OS X executes a boot sequence that readies the system for use. If you provide system services to all users, you might need to execute some code during this process. The following sections explain the basic boot sequence and the places where your code can tie into it.
In Mac OS X v10.4 Tiger, Apple introduced a new system startup program called launchd. The launchd daemon takes over many tasks from cron, xinetd, mach_init, and init, which are UNIX programs that traditionally have handled system initialization, called systems scripts, run startup items, and generally prepared the system for the user. And they still exist on Mac OS X Tiger, but launchd has superseded them in many instances. These venerable programs are widely used by system administrators, open source developers, managers of web services, even consumers who want to use cron to manage iCal scheduling, and they can still be called with launchd. The launchd daemon also provides a big performance boost to your system. At any given time, only those daemons that are actually used are launched
Edit the following file to fix this problem Add or modify text as follows: # vi /etc/sysctl.conf net.ipv4.tcp_tw_reuse = 0 net.ipv4.tcp_tw_recycle = 0 # sysctl -p The above command will help the new settings to take effect.
SystemImager is software which automates Linux installs, software distribution, and production deployment. SystemImager makes it easy to do automated installs (clones), software distribution, content or data distribution, configuration changes, and operating system updates to your network of Linux machines. You can even update from one Linux release version to another! It can also be used to ensure safe production deployments. By saving your current production image before updating to your new production image, you have a highly reliable contingency mechanism. If the new production enviroment is found to be flawed, simply roll-back to the last production image with a simple update command! Some typical environments include: Internet server farms, database server farms, high performance clusters, computer labs, and corporate desktop environments.
Many enterprise data centers rely on Ethernet for their LAN and data traffic, and on Fibre Channel (FC) networks for their storage infrastructure. With increased adoption of 10GbE in the data center, the availability of Fibre Channel over Ethernet (FCoE), and new lossless 10GbE technologies, it is now possible to consolidate FC SAN storage data flows with LAN and data traffic onto the same unified Ethernet cable. Network convergence will enable enterprises to preserve their existing investments in FC storage, reduce data center costs and complexity, and simplify network management.
If you've never abandoned your 4th grade obsession with the night sky (and who has?), Star Viewer is a web-based tool for peeking at some of the most interesting and vivid sights in the night sky. Star Viewer is not as complicated as, say, the previously mentioned open-source and feature-rich astronomy tool Stellarium
The Nikon system of digital single-lens reflex (SLR) bodies and lenses is a popular choice among serious photographers worldwide. This page makes it easy to shop for Nikon digital bodies and Nikkor lenses. Every component manufactured by Nikon is covered, plus a few exceptionally good third-party components. If you are new to photography, you might want to start with my article "Building a Digital SLR System".
"apt-fast and Axel: Roughly 26x Faster apt-get Installations and Upgrades Monday, 02 June 2008 Updated 12/17/2009 Since apt-fast has gotten popular due to acolades in the Ubuntu community and from mention in Linux Format, I've gotten lots of hits, and a few bugs. I believe that apt-fast is now golden, though, thanks to travisn000 on the PCLinuxOS forums. From now on, you can find the latest version "source" (it's just a shellscript) at http://www.mattparnell.com/linux/apt-fast/ ... the latest version will always be the one named "apt-fast.sh." Yes, this will work for any distro that uses apt-get, and the concept should work most of the others...it may even be as simple as removing wget and replacing it with a symlink to axel. Since I last updated this post, I have started using Archlinux, whose package manager has a system in place that allows any download manager to be used, for example."
Summary: Vimscript provides excellent support for operating on collections of data, a cornerstone of programming. In this third article in the series, learn how to use Vimscript's built-in lists to ease everyday operations such as reformatting lists, filtering sequences of filenames, and sorting sets of line numbers. You'll also walk through examples that demonstrate the power of lists to extend and enhance two common uses of Vim: creating a user-defined function to align assignment operators, and improving the built-in text completions mechanism.
swatch (the “Simple WATCHer”) does. swatch, written 100% in Perl, monitors logs as they're being written to and takes action when it finds something you've told it to look for. This simple, flexible and useful tool is a must-have for any healthily fearful system administrator.
Save a file you edited in vim without the needed permissionsI often forget to sudo before editing a file I don't have write permissions on. When you come to save that file and get the infamous "E212: Can't open file for writing", just issue that vim command in order to save the file without the need to save it to a temp file and then copy it back again. :w !sudo tee % Annotated link http://www.diigo.com/bookmark/http%3A%2F%2Fwww.commandlinefu.com%2Fcommands%2Fbrowse%2Fsort-by-votes
Linux Professional Institute (LPI) exam prep Self-study tutorials to help you learn Linux fundamentals and prepare for system administrator certification
device-mapper (dm): working with multipath-tools. Part 1 Filed under: SCSI, Linux — admin @ 10:33 Device-mapper (hereafter, dm) is one of the best collection of device drivers that I have ever worked with. It brings high availability, flexibility and more to the Linux 2.6 kernel. Device-mapper is a Linux 2.6 kernel infrastructure that provides a generic way to create virtual layers of a block device while supporting stripping, mirroring, snapshots, concatenation, multipathing, etc. While many modules are built on top of device-mapper, the focus of this article is on multipath-tools. Note that I will be using the terms multipath, multipath-tools and dm-multipath interchangeably to signify the same package. Also note that dm-multipath is the name of the repackaged multipath-tools redistributed under Red Hat in their Advanced Server Linux distribution.
One of the main advantages of using Negative type film is the ability to capture a wider dynamic range than can be achieved with Reversal types (slide/chromes). Unfortunately the image data is usually compressed into a much smaller density range. The big trade-off is our inability to immediately see the information due to the orange mask.
Create an iso image from the contents of a directory: mkisofs -hide-joliet-trans-tbl -l -J -f -T -r . > "../directory_dump_`basename $PWD`.iso" When run in a directory (say tmp) it will create a file called directory_dump_tmp.iso one directory higher, which will contain the contents of the tmp directory in it's root.
Friday, March 13, 2009 Extra Repositories for Ubuntu 8.10 You Might Want Ubuntu logoImage via Wikipedia The repository system is a great strength of open-source operating systems, but some people want the latest-and-greatest of a particular application while keeping the core system unchanged. There is also the situation where non-free applications aren't available from within the standard repositories. In these two cases, adding outside repos can help you get the functionality you want. I've done some homework for you and here are the "Extra Repositories for Ubuntu 8.10 You Might Want." Simply open up System > Administration > Software Sources and add the repository lines listed below as a third-party repository.
FOR MORE THAN HALF A CENTURY the eminent physicist Freeman Dyson has quietly resided in Princeton, N.J., on the wooded former farmland that is home to his employer, the Institute for Advanced Study, this country’s most rarefied community of scholars. Lately, however, since coming “out of the closet as far as global warming is concerned,” as Dyson sometimes puts it, there has been noise all around him. Chat rooms, Web threads, editors’ letter boxes and Dyson’s own e-mail queue resonate with a thermal current of invective in which Dyson has discovered himself variously described as “a pompous twit,” “a blowhard,” “a cesspool of misinformation,” “an old coot riding into the sunset” and, perhaps inevitably, “a mad scientist.”
The Thinsy Alfresco 3 for Active Directory is a Virtual Appliance that takes the monstrous complexity out of installing and configuring an Alfresco system. It enables you to bring up Alfresco for Active Directory in a matter of minutes! Download a virtual appliance, and fire up the VM. Full GUI Configuration is included in the virtual appliance. You will not need to log into the underlying linux system to perform any administration tasks.
Talis Connected Commons The Talis Connected Commons scheme is intended to directly support the publishing and reuse of Linked Data in the public domain by removing the costs associated with those activities. The scheme is intended to support a wide range of different forms of data publishing. For example scientific researchers seeking to share their research data
Feb. 25 (Bloomberg) -- It was 2004 and Tim Geithner, president of the Federal Reserve Bank of New York, had a message for the Federal Open Market Committee in Washington. He told his 18 colleagues gathered around the long mahogany table that a clearinghouse was needed to monitor risks in the burgeoning $5 trillion market for credit-default swaps -- the over-the-counter derivatives that would later spin out of control and help take down Wall Street.
EUCALYPTUS - Elastic Utility Computing Architecture for Linking Your Programs To Useful Systems - is an open-source software infrastructure for implementing "cloud computing" on clusters. The current interface to EUCALYPTUS is compatible with Amazon's EC2 interface, but the infrastructure is designed to support multiple client-side interfaces. EUCALYPTUS is implemented using commonly available Linux tools and basic Web-service technologies making it easy to install and maintain.
I have written many administration guides which cover all of the VMware Enterprise Products (ESX, vCenter, P2V). They have been created in a PDF format.
#2: Replacing same text in multiple files * Difficulty: Intermediate * Application: find/Perl If you have text you want to replace in multiple locations, there are several ways to do this. To replace the text Windows with Linux in all files in current directory called test[something] you can run this: perl -i -pe 's/Windows/Linux/
R Commander is a GUI for the R programming language, licensed under the GNU General Public License. Among the existing R GUIs, Rcmdr together with its plug-ins is perhaps the more viable R-alternative to commercial statistical packages like SPSS. The package is highly useful to R novices, since for each analysis run it displays the underlying R code.
Steampunk is Goth, Punk, Geek, and Maker Culture whipped into a delicious melange with a healthy seasoning of political and environmental activism. It's the intersection of science and romance, it's sustainable rebellion.
Dimdim Open Source Community Edition v4.5 “Liberty” is meant for developers, highly technical enthusiasts and for use in non-critical environments. It has the most of the features of Dimdim Enterprise and is based on open source streaming and media components. Dimdim Enterprise is based on commercial streaming and media components (Adobe Flash Server) and runs on top of our SynchroLive Communication Platform to ensure robust scalability and reliability and is fully supported and certified by Dimdim, Inc. The Open source community supports the Open Source Community Edition.