Month: November 2008

Restoring your system after a crash

Ok, so your computer crashed. You know one way out: reformatting the hard disk – but you don’t like it. So what can be done? If your data is really important, and you are prepared to pay some hard bucks getting it back, talk to a professional. Period.

Still here, ok – so your data is important, but you want to do what you can, yourself. I will discuss in the blogpost some tools that can help.

One of the best recovery tools, that has helped me as well, is: Emergency Boot CD (EBCD). The original site seems to be no longer active, and it hasn’t been updated since 2004, but its still a great tool. Look for it here, or here, or Google search for it.
With this, you can recover deleted files, or those lost by formatting. You can fix master boot record. It will allow you to boot from a specific partition, even if its being shown ‘non-system’ otherwise. Once you have the system up through EBCD, on XP you can run the ‘bootok.exe’ command, or ‘fixmbr.exe’ to fix any issues, its available in /windows/system32.
EBCD includes Windows Password Wizard, which can be used to restore access to your PC when you forgot the password for Windows user account.

The next option I am going to talk about is “Bart’s Preinstalled environment bootable live CD” (BartPE). However, using this is not just a matter of downloading an ISO and burning a CD, as it was for the EBCD. You will need to create the CD from your Windows XP CD. The instructions are on the BartPE website. One you have the CD ready, you can boot off the CD into a live Windows XP environment with a lot of tools available. You can even access NTFS drives. See where you can get with this. Again, once you have the system booted, try running bootok.exe as I suggested above.

Another option, if you cannot/do-not-want-to get the BartPE built, is a Knoppix Live CD. This will boot your computer with Linux OS, which is not very difficult to use given Windows knowledge. However, other than getting your computer running, this will not do much more to fix your problem.

The last recovery tool I am going to talk about is System rescue disk. This one offers the GParted tool, which is a disk partition management tool (similar to FDISK) but can resize partitions without loosing data.

If you are unable to download/lay your hands on one of these CDs, I can have them shipped out to you for a fee (except, of course the BartPE).

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DNS poisoning – in plain English :-)

What is DNS poisoning, why it affects everyone accessing the internet and how to fix it.

Computers do not have names, only numbers. For example, Yahoo! is 68.180.206.184. When you ask your browser to be taken to Yahoo.com, it looks up this number in something similar to a telephone directory.

A person by the name Dan Kaminsky has found that it’s possible for someone (called X henceforth) to modify the directory. So, when you ask for Yahoo, the computer would lookup the wrong number, a number to a computer owned by X. Thereafter, it can record the information you give it, thinking that its Yahoo!. The owner may then misuse this information.

So what do you do to make sure this doesn’t happen? First, check your DNS server (the machine that tells your computer what number a website has) by going to http://www.doxpara.com/.
If that says your computer is vulnerable, change your DNS servers. Detailed instructions for different operating systems are here. For Windows, in short you have to change your DNS settings to 208.67.222.222 and 208.67.220.220 by going to Network Connections.

Note: This is not a security update blog, and I do not talk about every vulnerability. However, this one is important and everyone needs to understand it. On the other hand, most forums on the web talk highly techno. Read this one for more information, only if you think you need it!

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Golden Temple

Ok, my very first Flash based web album is here: The Golden Temple.

The Golden Temple, at Amritsar, India is the most significant place of worship of the Sikh religion, and one of the oldest. The temple is called Harmandar Sahib, and is indeed covered by a layer of Gold.

I always had the feeling that you would need to buy Adobe Flash to build Flash albums, or at least other paid software. I had always used JAlbum to build my web albums. However, to my surprise there are free skins for JAlbum that let you build such Flash web albums.

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The Spirograph

I became a kid again and purchased a Spirograph set. The Spirograph is a mathematical toy, which you can use for drawing nice figures. In the simplest case it exists of a fixed circle, used as a template, and a smaller rolling circle with holes. The result of my experiment is at the end of this post.
Thereafter, I turned my attention to mathematical generation of the Spirograph figures, and to my surprise I was able to find a number of good resources on the net.
The parametric equations for a Spirograph are:
x(t)=(R+r)cos(t) + p*cos((R+r)t/r)
y(t)=(R+r)sin(t) + p*sin((R+r)t/r)

More explanation here:
http://www.mathematische-basteleien.de/spirographs.htm

A digital spirograph can be created using, for example, the following equations:
(5-1.02)*cos(1.02*x/5)+2*cos((5-1.02/5)*x)
(5-1.02)*sin(1.02*x/5)+2*sin((5-1.02/5)*x)
with HSB Grapher.

An applet, and some data to play with it can be found here.
However, what I found more useful and interesting is this page: http://linuxgazette.net/133/luana.html. It provides a Spirograph compiler (an awk script). This awk script takes a Spirograph specification and generates a gnuplot script to create the Spirograph. Go try it – its very interesting. If you are on windows, read these to help you get started on awk and gnuplot.

Spirograph
Spirograph

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Forest fire

Forest fire
Forest fire
The current economical state, at least in India seems to me to be like a forest fire. A forest fire burns out all the dying vegetation that is blocking the sunlight and makes conditions suitable for new growth. It resets everything back to where it was. It’s a new beginning.

In times of growth and good earning, we settle down comfortably and over a period, our intrinsic cost increases. When I say intrinsic cost it also includes costs that are incurred by third parties, directly or indirectly for us. For example, if my office sponsors transport facility for me without charging me for it, it’s included in the intrinsic cost.

At times like this, each cost is re-thought about. “Do we really need it?” When the office cuts transport people think “Can I work closer to where I live?” or “Can I shift my residence closer to office?”. In good times there was never need to ask these questions, but now there is. Overall the cost goes down. People are doing something they should have done anyways, but did not just for comfort.

There is mass upheaval, but there is also rationalisation. If too many people have joined the IT industry (more than what is intrinsically needed), some will join the biotech sector for example, if that is an emerging sector. Again, it something that should have happened anyway.

So the point is, upheaval and rationlisation are good. While these move us out of our comfort zones at the moment, they are better for the long term.

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Guru Nanak prakash utsav

I visited the Nagar Keertan yesterday, on the occasion of Gurn Nanak Prakash Utsav. Prakash Utsav means celebrating the day the Divine Light (of Knowledge) spread.

The thought that struck me during the hymn singing was this:

ਸਾਧੂ ਸੰਗਿ ਸਿਖਾਇਓ ਨਾਮੁ ||
ਸਰਬ ਮਨੋਰਥ ਪੂਰਨ ਕਾਮ ||

The translation:

In the Saadh Sangat, the Company of the Holy, the Naam (Lord’s True Name) is learned; (and through the Lord’s Name) all desires and tasks are fulfilled.

It struck me because it very simply conveys the fact that the Lord’s Name is one stop solution to fulfillment of tasks. There is no need to be superstitious – go take refuge in the Name of the Almighty.

Further reading:

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Brown plant hopper in Delhi

Till around Oct 28th, it was difficult to walk the Delhi streets with the head held high. Talking, eating was absolutely out of question.

Brown Plant Hopper
Brown Plant Hopper

The reason? The brown plant hopper had migrated to Delhi from Haryana and neighbouring places in hoards. They would get into your mouth, eyes, clothes, and everyplace else! This ‘pest’ is present in rice plants, and because of the harvest season and because it had developed immunity to the used pesticides – it followed the wind to Delhi looking for food.
Here is a computer coloured photo of an image I took, pests around a lamppost:
Lamppost

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Upagupta – a poem by Tagore

Upagupta
Upagupta

Upagupta is a beautiful work by Tagore. The story goes as follows:

Upagupta is a disciple of Buddha, and goes from one place to another. He is sleeping in a small town when a dancing girl wakes him up and requests him to sleep at her home. Upagupta refuses, and tells her “I will visit you when the time is ripe.”.
A year later, and again on travel to the same place, Upagupta finds the dancing girl lying on the ground outside the town, having sores all over the body and shunned by the townsfolk. He applies balm on her body and when asked who he was, he replies “The time has come to visit you and I am here.”

Please read the whole poem, it’s beautiful. What I like about the poem is – how Tagore contrasts Time. When the dancing girl is giddy with pride, Upagupta knows its not going to last.

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Chandrayaan I

Chandrayaan I, India’s maiden unmanned moon mission has sent through its maiden photograph – one of looking back at Earth:

Chandrayaan maiden photo
Chandrayaan maiden photo

It’s a proud moment for us Indians, being able to look back at Earth from so far off.

It’s still on its way to the Moon, scheduled to reach on Nov 8th. Let’s watch out for more photos then.

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