In mathematics, a spherical coordinate system is a coordinate system for three-dimensional space where the position of a point is specified by three numbers: the radial distance of that point from a fixed origin, its elevation angle measured from a fixed plane, and the azimuth angle of its orthogonal projection on that plane, measured from a fixed reference direction on the same. The elevation angle is often replaced by the inclination angle measured from a zenith direction perpendicular to the reference plane.

"This article will describe the definition and usage of the Eclipse Extension Point mechanism. The examples used will be based on Eclipse RCP therefore basic knowledge of Eclipse plugin or Eclipse RCP development is assumed."

English to Latin dictionary search.

"RANDOM.ORG offers true random numbers to anyone on the Internet. The randomness comes from atmospheric noise, which for many purposes is better than the pseudo-random number algorithms typically used in computer programs."

Using GNU Date to do date math like getting last months date.

The same way tabbed browsing revolutionized the web experience, GNU Screen can do the same for your experience in the command line. GNU Screen allows you to manage several interactive shell instances within the same “window.” By using different keyboard shortcuts, you are able to shuffle through the shell instances, access any of them directly, create new ones, kill old ones, attach and detach existing ones.

Personal time management skills are essential skills for effective people. People who use these techniques routinely are the highest achievers in all walks of life, from business to sport to public service. If you use these skills well, then you will be able to function exceptionally well, even under intense pressure.

"You are logged into your remote server via SSH and happily plucking along at your keyboard and then it happens. Suddenly, the characters stop moving and then you get the dreaded “Connection Closed” message. You have just lost your session. You were halfway through some task and now you have to start over. Ugh. Well you can prevent this from happening by using screen."

What is the maximum number of physical extents in LVM? The answer is that there's no limit on the number of PEs within a Physical Volume (PV) or Volume Group (VG). The limitation is, instead, the maximum number of PEs that can be formed into a Logical Volume (LV). So a 32MB PE size allows for LVs up to 2TB in size.

Amazon s3 is a remote file storing system. It is totally different from Normal Servers like Apache, FTP server etc. If your site burns more bandwidth due to backups or multimedia contents such a video, image, audio etc, the maintenance cost will be very high. For a limited number of page views, local file saving mechanism is ok. Because the cost of bandwidth is comparatively low. But when the data transfer rate become higher, the bandwidth cost should be considered.

This book describes the LVM logical volume manager, including information on running LVM in a clustered environment. The content of this document is specific to the LVM2 release in Red Hat Enterprise Linux Release 4.5.

I joined Microsoft in 1993 when it was hitting its stride. It had recently released Windows 3.1 and Windows NT, setting itself on the path of more than a decade of dominance in the PC operating system market, and the many other markets that flow from it. I worked as a programmer for 11 years in various different groups — on databases, Windows, Office, MSN, mobility, and research.

One day it just hit me — I should quit.

HOWTO Restore GRUB

GNU GRUB Manual 0.97

virt-image(1) relies on an XML descriptor to create virtual machines from virtual machine images. In general, a virtual machine image consists of the XML descriptor (usually in a file image.xml) and a number of files for the virtual machine's disks.

Unlike virt-manager, virt-install is a command line tool that allows you to create KVM guests on a headless server. You may ask yourself: "But I can use vmbuilder to do this, why do I need virt-install?" The difference between virt-install and vmbuilder is that vmbuilder is for creating Ubuntu-based guests, whereas virt-install lets you install all kinds of operating systems (e.g. Linux, Windows, Solaris, FreeBSD, OpenBSD) and distributions in a guest, just like virt-manager. This article shows how you can use it on an Ubuntu 8.10 KVM server.

The RCS version control system insures that changes made are not lost, that there is a log of modifications made – this will allow you track why things were done is specific ways, and RCS will allow you to revert to older versions – this is usually done because the current version may have errors or not be applicable to a particular use. RCS is easy to install, does not require any server processes or complex configuration, and it has a very steep learning curve – you will be up and running within minutes and RCS will save you loads of time the first instance you have to refer to the log messages or have to revert to a previous version of a file.