Speed of light, time and space (wide view study):

Speed of light is one of the most things I read about, I know that I am not a physician but I got my logic, regarding logic as the base of all sciences, so what is speed of light in my point of view.

At first think of yourself on a road of two ends, and you was standing at one end, then you run three times faster than the speed of light, arrive to the second end of the road and turn back, logically what you will see?, just think of it.

Dell OptiPlex 330 Diagnostic "Error" Lights:

Dell OptiPlex 330 Diagnostic "Error" Lights:

Many Dell OptiPlex models have diagnostic or error lights in the front or the back panels, the idea of that lights is to help to identify the state of the PC components, so here we will talk about these lights states and how we can fix them.

Converting POE incompatible Network device to a POE compatible device.

How to convert  POE incompatible Network device to a POE compatible device:

At first refer to our previous post on how to make a homemade POE Injector.

http://rudaini.blogspot.com/2012/06/home-made-poe-injector.html 

Now we will use the Linksys wap54g wireless access point as an example.

As the POE device it means that it is not directly connected to the power adapter, it takes the needed power from the Ethernet cable, but this device is not a POE compatible, we will see the required steps to convert it to a POE compatible device.

Home Made POE Injector

Home Made POE Injector:

POE: Power over Ethernet, is a technology used to deliver electrical power to a POE Device over the Ethernet cabling.

the POE Injector used to merge the power signal and the Ethernet signal using one Ethernet cable connected directly connected to the POE device or by using POE enabled switches or routers.

Activating Internet Download Manager without any crack

Activating Internet Download Manager without any crack or patch:

This is how to activate Internet Download Manager with out any crack or patch

First: Download and install any version of the program, then install it on your device.

USB Flash Disk Fixing Part 1: Components

We all have some flash disks that is not working, or working with some problems, so at first I should start with flash disk components and their job so when we face the problems we can know which part/s is/are the reason of each problem.

The Personal Goal

The life is not that extended, so anyone can say “I will reach all my goals in it”, in other hand even if my goals still unreachable in my life the best way to feel my satisfaction is to carry it to a level so other interested people can achieve it after my life.

 

The Idea of Sharing:

Aims for others may be as small as “my goal is something” thus when they reach their ambition they lose themselves cause they don’t realize what is the next stage, or if they don't reach it, their condition will still the same, thus for me the vision is different as “my objective is the most excellence of me” so I will always hunt of the next stage of my objective, and even not that only, I will try joining in others goals.

Silent Meditation

Silent Meditation

For many people the silence is a fuzzy state, this is what they think cause they don’t give it enough envision, that’s because they're not capable of staying in silence for long time, other people think of silence as the part of divine-self of the human like Love, Emotions, Inner lightning, and other concepts, they may be right, but for me the silence is the edge between inner-self and outer-self of our humanity.

SNAPGEAR URL FILTERING

SNAPGEAR URL FILTERING:

Basic features

1. What filtering application does SnapGear use?

SnapGear offers a version of Secure Computing’s leading Webwasher® URL filtering solution. SnapGear Webwasher filtering uses the same URL database/filtering engine found in the Webwasher enterprise SCM solution. The SnapGear filtering module provides basic filtering functionality that is targeted for smaller businesses. Not all of the Webwasher advanced/enterprise filtering features are included.

 

Working With DHCP Server In Linux

Introduction

Normally if you have a cable modem or DSL, you get your home PC's IP address dynamically assigned from your service provider. If you install a home cable/DSL router between your modem and home network, your PC will most likely get its IP address at boot time from the home router instead. You can choose to disable the DHCP server feature on your home router and set up a Linux box as the DHCP server.

Download and Install the DHCP Package

Most RedHat and Fedora Linux software product packages are available in the RPM format, whereas Debian and Ubuntu Linux use DEB format installation files. When searching for these packages, remember that the filename usually starts with the software package name and is followed by a version number, as in dhcp-3.23.58-4.i386.rpm.

Note: With Fedora / Redhat the package to install would be dhcp. With Debian / Ubuntu the package is dhcp3-server.

RAID part 3 RAID Level 1.

RAID Level 1

RAID level 1 is known as disk mirroring. Disk mirroring uses two or more hard drives and duplicates the data from one drive to the others. The fact that RAID 1 does store a second copy of the data on another member of the volume means that this solution does offer fault tolerance. Fault tolerance is the concept that if one part of the solution fails, the other guy will pick up the workload and the solution will continue to function. If one of the disks in the mirror fails, you can replace the failed disk by breaking the mirror, adding a new functioning disk, and then rebuilding the mirror from the existing disk that did not fail. Once you have reestablished the mirror, you have your fault tolerance back.

The figure below displays the concept of a mirror volume. When a user saves data to a mirrored volume, the data is written to all disks that make up the volume.

RAID level 1 (Mirror) concept.

Creating a Mirrored Volume in Windows Server

In this step-by-step you will create a mirrored volume on a Windows server using two of the dynamic disks created in the preceding walkthrough. Remember that a mirrored volume stores all the data on both members (disks) in the volume. To create a mirrored volume, follow these steps:

RAID part 2 RAID Level 0.

RAID Level 0:

RAID level 0 is called striping or striped volumes. With RAID 0 multiple disks are used to create a volume; when data is saved to the volume, the data is split up and spread across all disks in the volume. The benefit of striped volumes is that all disks are written to at the same time, giving you a performance benefit. For example, if you are saving a 12MB file to drive D and drive D is a striped volume made up of four disks, we can generalize the save operation by saying that each disk will save 3MB of data each and all disks will work at the same time to do the save operation that totals 12MB. If you only had one disk working for that 12MB save operation, it would take four times longer.

RAID 0 "Striped set without parity" or "Striping". Provides improved performance and additional storage but no redundancy or fault tolerance. Because there is no redundancy, this level is not actually a Redundant Array of Inexpensive Disks, i.e. not true RAID. However, because of the similarities to RAID (especially the need for a controller to distribute data across multiple disks), simple stripe sets are normally referred to as RAID 0. Any disk failure destroys the array, which has greater consequences with more disks in the array (at a minimum, catastrophic data loss is twice as severe compared to single drives without RAID). A single disk failure destroys the entire array because when data is written to a RAID 0 drive, the data is broken into fragments. The number of fragments is dictated by the number of disks in the array. The fragments are written to their respective disks simultaneously on the same sector. This allows smaller sections of the entire chunk of data to be read off the drive in parallel, increasing bandwidth. RAID 0 does not implement error checking so any error is unrecoverable. More disks in the array means higher bandwidth, but greater risk of data loss.RAID 0 is strictly for the performance benefit in the read and write operations.

RAID level 0 concept.

RAID part 1 Introduction.

Introduction:

A Redundant Array of Independent Disks (RAID) controller is a piece of hardware or system software that control and manage the RAID level of the RAID storage, it is largely used in servers because they have a large space of storage that importantly be recoverable and secure.

The RAID controller is also largely used in clustered environments like Network-attached storage (NAS), which are standalone devices, usually SCSI, that have a network interface but no PC. NAS is possibly include a built-in RAID controller to allow all the hard disks to be fault tolerant and function as a single volume.