Sunday, February 6, 2011

F-O-S-S Explained

1. Free Software :

Free software is software for which everyone has the right not only to inspect and study the source code but also to use it for any desired purpose without monetary or other restrictions. These other purposes include making as many copies as desired, installing on as many computers as desired, modifying (including extending) in any desired way, and redistributing in its original or modified form.
As defined by Free Software foundation, its a software whose licensing conditions promise following 4 freedoms

* Freedom 0: freedom to run the program for any purpose. Eg. Softwares restricted for educational use hinders this freedom (like those distributed under MicroSoft Academic Alliance)
* Freedom 1: freedom to study how the program works, and change it to make it do what you wish. Eg. Softwares whose licensing terms forbids reverse engineering curtails this freedom
* Freedom 2: freedom to redistribute copies. Eg. softwares (eg. WinXP) whose licensing terms forbids copying of software and using it on multiple systems curtails this freedom.
* Freedom 3: freedom to improve the program, and release your improvements (and modified versions) to the public. Eg. freewares which can be downloaded for free (of cost) but modifying them and then distributing modified copy is violation of license agreement (hence, violating copyright law).

2. Open-Source Software Open source software is software whose source code is freely available for anyone to inspect and study. A free software is always also open source, open source software does not necessarily have to be free software.

3. Free and Open-Source Software : When a software combines the above two features, the same can be said to fall under the category of FOSS. Wikipedia : Its a software that is liberally licensed to grant the right of users to use, study, change, and improve its design through the availability of its source code.

So, on the closing note a free software is more about “freedom” rather than zero-price.

Source : Wikipedia,opensource.org,linfo.org,ashishb.net

Thursday, August 5, 2010

Btrfs - System Rollback comes to Fedora

Btrfs helps in creating lightweight filesystem snapshots that can be mounted (and booted into) selectively. The created snapshots are copy-on-write snapshots, hence there is no file duplication overhead involved for files that do not change between snapshots.
A "rollback" to an older snapshot is non destructive for other snapshots. If user switches to an earlier snapshot, the later snapshots will still be available afterwards.

Btffs will allow users to :
1. Automatically create new disk snapshots before each yum transaction.
2. Change which snapshot will be next booted into, if neded.
3. Manually create a new snapshot, if needed.

For carrying out any of the above mentioned tasks under Btrfs user need to have Root user privileges.

PS : Btrfs is a File system type, so if you desire for a partition to be Btrfs strong you need to format the partition with FS type set to Btrfs.

Saturday, April 3, 2010

Downloading RPM's using YUM

YUM now provides you with the ability to :
1. Download the RPM's without installing them.
2. Just get the list of URLs from where the RPM's would be downloaded.
3. Resolve the dependencies for the package that you plan to download, and get then too along with the package.
4. Get the source if you are intrested in that being more geeky.

And not just this much , yum will get you all this specific to your release and arch,so no more no-arch packages.

So here is how to go with this :
First of all you need to install the package 'yum-utils' as the utility that provides all this functionality using the configuration of YUM. Make sure that this all will work using the repos (software repositories both online and offline (if-any)) configured under /etc/yum.repos.d/ that are used by YUM for package searching, dependency resolution and many other packages related tasks. It all depends on the configuration in the repo files, using which yum will be looking up the packages in the stable and unstable repositories.

1. Download of RPM's
# yumdownloader firefox
The command will download the latest firefox from the closeset repository , into the PWD.
2. URL's of the RPM.
# yumdownloader --urls firefox
This will be listing the location [URL] of the RPM's, but will not download them, hence saving the bandwidth.
3. Installation of packages sometime need other packages for its installation known as 'Dependencies'. If these are missing the package will not install.
So in order to install all of the dependent packages we need to fire.
# yumdownloader --resolve firefox
If we only need to see the dependent packages without installing them, in that case the command need to be edited with
# yumdownloader --urls --resolve firefox
4. As listed above 'yumdownloader' just lists/ download the RPM's by default but incase if you want to get the source packages, we need to add the option '--source' to the query.
# yumdownloader --source firefox
In order to just get the URL's of the scource packages, the command need to be edited a bit.
# yumdownloader --urls --source firefox
And if one need the URL's of the scource packages along with the source of the dependencies, the command will look like.
# yumdownloader --urls --resolve --source firefox

Once you have the RPM's you can install them using different methods, either by 'rpm' command or by 'yum'.