Wednesday, 31 March 2010

How to create your Linux installation CD / DVD in Windows

After downloading a Linux distribution of your choice the next major step is to create the installation CD or DVD.

You will more than likely have downloaded a disc image (*.iso) file which needs to be burnt to a CD or DVD and is a simple process.

However even the most simplest of tasks can have complications caused by a number of factors, for example a corrupted download, poor CD / DVD media, a rubbish DVD writer drive or poor burning software.

I have in the past encounted issues as a result of a poor DVD Writer I once had, an NEC ND-2510A which has to be the worse optical drive I have ever owned. It has created more frisbees than discs.

For the past fews years I have been using a Sony AW-G170A DVD Writer optical drive and it has been extremely reliable. I have yet to have a burn go wrong.

A very common cause of corrupted installation media is due to using very cheap unbranded poor quality discs. Good quality discs are cheap enough anyway, so stay away from these silver frisbees!

Verify your downloaded disc image before burning it

It is sometimes a good idea to verify your downloaded disc image before burning it to make sure it is not corrupt or modified.

You may notice an MD5 or SHA1 checksum is provided for your download.

If the MD5 / SHA1 checksum of the file you have downloaded does not match the MD5 / SHA1 checksum listed, it simply means you have a different file.

How to find the MD5 or SHA1 of a file?

I use this cool utility called HashTab, it is available from http://beeblebrox.org/

Once installed, right click on the file you wish to check and select properties. Then click on the tab labelled 'File Hashes'


Note: The Hash Values in this picture are for illustrative purposes only!

Burning your Linux disc image

Use your favourite image burning software or if you do not have one here are two very good free programs that I would recommend.

ImgBurn

http://www.imgburn.com/

Launch ImgBurn > write image file to disc > select the file > click on write

CDBurnerXP

http://cdburnerxp.se/

Launch CDBurnerXP > Burn ISO iamge > select your file > Burn disc

Disc Image burning FAQ's

Q. I created a disc but during installation it is reported as being corrupted and fails.

A. Try burning at a lower speed, for example if your disc media is rated at 16x try 8x. This will result in a better burn. Alternatively try a different brand disc or if using a RW use a R.

Q. My Optical writer has trouble reading / writing the majority of DVD-R and DVD+R discs.

A. Try updating your optical drive's firmware. If that fails, maybe its time for a newer drive.

Q. Should I use DVD-R or DVD+R?

A. Doesnt matter, but generally DVD-R is more widely used.

Q. Is it ok to use Re-Write (RW) discs instead of Write once (R) discs?

A. Yes but the write speed of most RW discs is significantly slower than R discs and you may also encounter further issues with RW discs, for example other optical drives apart from the original used to create the disc may have difficulty reading the disc you created.

Compatibility with RW discs is still an issue. Given the price, write speed and above issues, I would suggest to stick to R discs only for better reliability.

Q. I know my Optical drive and DVD media are good but the installation says the media is corrupt.

A. Try the some of the above recommendations and also verify the downloaded disc image by comparing the md5 checksum / SHA1 or GPG key.

Use a different burning program such as ImgBurn.  

Alternatively try a different Optical drive, get someone else to burn the disc. If it works, your "I know my Optical blabla bla works" could be nothing more than a bad assumption.

Sunday, 28 March 2010

Fedora 12 – Improving the awful font rendering

Fedora 14 Users look here - http://linuxtweaking.blogspot.com/2010/11/fedora-14-how-to-improve-font-rendering.html

If you have compared Fedora to other distributions you may have observed the default font rendering in Fedora is quite horrible.

Below is a screen shot of a default Fedora 12 desktop. The fonts seem blurred and bold.


By default Fedora has three main issues when it comes to fonts.

1. The default font used and font rendering is awful.

2. It lacks the true type fonts required by many websites. As a result web pages look wrong / not nice.

3. The bytecode interpreter (patent bit of code) required to make true type fonts look nice is missing.  http://www.freetype.org/patents.html

The good news is all of the above can easily be fixed by changing the default font rendering, installing the missing true type fonts and installing the bytecode interpreter.

Changing the default font rendering

Navigate to System > Preferences > Appearance

The following window will appear.


I found ‘Subpixel smoothing (LCDs)’ was the best option but that is my personal view. Use what you think looks good.

Since I do not like the default fonts I change them to the Liberation fonts which are included in Fedora. https://fedorahosted.org/liberation-fonts/


The result of these changes can be seen in the above screen shot. Compare this to the very first screen shot at the beginning of this article or look at the difference on your system.

What do you think, better or worse?

Installing the True Type fonts

I simply copy all the true type fonts from a Windows system to a USB memory stick and then to the /usr/share/fonts/ directory.

Optimal use of True Type fonts, installing the Bytecode interpreter

You will need to enable the RPM Fusion repository on your system. Refer to http://rpmfusion.org/Configuration

Now using the terminal type / paste the following,

su –c ‘yum install freetype-freeworld’

Close the terminal and reboot your system.

Browsing web sites with Firefox should now look nicer as you have all the required fonts and the bytecode interpreter enabled.

Or if your University requires all assignments to be written with Arial font, you now have that option in OpenOffice.