Bala-Krishna

What happen when you perform read/write disk operation like delete a folder, copying files. Take a closer look inside hard drive to see what exactly happen. This video show operations performed by a hard drive without cover. Do not try to exercise this on your hard drive. It may damage your hard disk permanently. Try at your own risk.

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^”`$$-
!*=@$_
%*<>~4
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|{,,SYSTEM HALTED

If we use the proper cyber names then it will be translated like this

Waka waka bang splat tick tick hash,
Caret quote back-tick dollar dollar dash,
Bang splat equal at dollar under-score,
Percent splat waka waka tilde number four,
Ampersand bracket bracket dot dot slash,
Vertical-bar curly-bracket comma comma CRASH

WHM is a Web Host Manager tool that allows server administrators to quickly and easily add new web hosting accounts on a WHM enabled Web server. Here is steps to create new hosting account without hassle.

1. Log into WHM account with your username and password.
2. Click the Create a New Account link from the Account Functions menu.
3. Enter the domain name into the Domain field, and the username into the UserName field. The UserName field will initially default to a name based on the domain you enter, but you may change it if you wish.
4. Enter a password into the Password field, and the disk quota into the Quota field. The Quota field, measured in MegaBytes, controls how much hard-disk space the new account is allotted.
5. Decide whether to allow CGI access, Shell access and FrontPage extensions, then check the respective boxes accordingly.
6. Decide on limits for the following boxes and enter values for each in the text field for each: Max FTP Accounts, Max Email Accounts, Max Email Lists, Max SQL Databases and Max Sub Domains.
7. Enter the maximum bandwidth for the account (in MegaBytes) into the Bandwidth Limit field.
8. Click on “Create” button.

There are lot of commands to manage users in Linux box but i could not find a single command to list all users in system. The “users” command only show login users not all user in system. After a tremendous research i found a way to list down all users in command shell. This is necessary in some event when you don’t know users in Linux box.. for example. you want to see Cron job setup in Linux box for a particular user. The Linux does not have any command to list down Cron job unless you know user name.

List Cron Job of current login user

# crontab -l

List Cron Job of other user from root

# crontab -u username -l

Here is various list command to get user list.

• All user list including special user created.
  

  cat /etc/passwd

• Only show normal users created by root. Normal user id is 500 or above so this command will normal users.
  

  cat /etc/passwd |grep 500*

• Shows users with a home directory.
  

  cat /etc/passwd | grep /home | cut -d: -f1

IE Tab is an extension for Firefox allow you to embed internet explorer in firefox tab. This is good tool for web developer to check website design in internet explorer with out using internet explorer.

Drawback:

1. IE’s ActiveX settings does’t work.
2. Navigation history list does’t work.
3. Doesn’t work in environment where IE not available such as under Linux.

Accessibility:

It can be accessible via several way:

1. Option available to switch render engine Firefox to Internet Explorer and vice versa by right click on address bar.
2. Accessible by right click on page and hyper link on a page.
   

It is known that Google using MySQL 4 for some of the their light application that are not related to search technology. However, It has been patched according to the requirement and available to download from Google website. Google guys patched to make MySql more stable in the area of high availability and manageability.

New Features Added.

• Support for semi-synchronous replication
• Mirroring the binlog from a master to a slave
• Quickly promoting a slave to a master during fail over
• Keeping InnoDB and replication state on a slave consistent during crash recovery
• New SQL statements for monitoring resource usage by table and account
• Number of seconds of database time an account uses to execute SQL commands.

The new MySQL has been released with GPL licence and available to download from following location.

http://code.google.com/p/google-mysql-tools/

DNAStream is new service allow to view video clips online in web based environment. You don’t need to download any software and install in your machine. You only required flash player installed on your machine to make application work. DNAStream uses flash to stream video. The look and feel of the interface looks very similar to Joost.

The content quality of the application is good similar to Joost. It streaming numerous television channel, internet video, music videos and documentaries.

Beside of all these, DNAStream using same look and feel as Joost and may face copyright infringement issues.

All are above medium are used to connect one computer with another with different sets of capabilities.

Let see how the working of these devices differ from each other:

Hubs

Hub basically a shared connection point for computers in a network enable computers in a network to communicate each other. A hub contains multiple Ethernet cable connection port to plug in the Ethernet cable. Hub can not recognize receiver address of a packet it receives, When a packet arrives to it, the packet transmit to all computer connected to hub. The packets received by intended receiver and discarded by other computer in a network. A hub can send or receive packets in network but it can not perform both the operation at the same time. Also the hub are cheaper then switches and router.

Summary

• Hub can not recognize destination address of a packets, so it is slower because of packet unnecessarily send all computer in a network
• Do not support concurrent send and receive operation
• Cheaper then switches and routers
• Work on broadcasting methodology, So lot of traffic on the network that can lead to poor network response times

Switches

Unlike the hub, Switch works in a different way. Switch can identify receiver address of information packet, so switch only send packet to identified computer. Switch can perform send and receive operation at the same time, so the response time is much better then hub. Switch filter packet by their destination address and forward them. It works on Data link layer and Network layer of OSI Reference model.

Summary

• Identify packet receiver address and forward only to them
• support concurrent send and receive operation
• Costly then hub and cheaper then routers
• Better network response time then hub
• Works on Data link layer and Network layer of OSI model

Routers

Typically, A router is used to connect to at least two networks, commonly two LANs(Local Area Network) or WANs(Wide Area Networks) or a LAN and its ISPs(Internet Service Provider) network. Routers works completely different hub and switches. Hub or switch is concerned with transmitting packets, a router’s job is to route packets to other networks until that packet ultimately reaches its destination. Router ensure proper delivery of packet to intended destination.

Summary

• Connect two network either LAN or WAN
• It rout packet rather then transmit to computers link switch and hub
• Ensure proper delivery of packet.
• expensive than hubs and switches.

According to Technology Review, Computer-science professor Josep Torrellas discovered a better way to deal with faulty chips: an efficient repair mechanism that treats hardware much more like software, by fixing bugs with downloadable patches. Josep Torrellas invention still in development phase, but his invention could make micro chip production faster and cheaper.

Torrellas’s system is special hardware that will embedded on the chip and would be programmed to detect defects and implement solutions.

DDR2

• Operate at 400MHz to 800MHz.
• operates at 1.8V
• 4 internal banks used
• based on “T branches” conventional topology
• (OCD) off-chip driver calibration
• can not deal with termination impedance
• popular in industry.
• No Thermal Sensor

DDR3

• Operate at 800MHz to 1666 MHz. This will reduce read and write time to just half of the DDR2 memory.
• operates at 1.5V
• 8 internal banks used
• initialization process uses new Mode Registers (MRS) are re-engineered for quicker configuration of the memory system.
• based on “Fly-by” topology
• Self calibration with automatic leveling circuit
• can deal with termination impedances
• It will take time to be as mainstream memory
• Optional Thermal sensor