Tuesday, October 20, 2009

Configuring Software Repositories

The main Ubuntu installation includes a graphical utility that allows you to easily configure your Ubuntu system to access different software repositories. You can start the
Software Sources tool by selecting System -> Administration -> Software Sources from the Panel menu.

The Software Sources window contains five tabbed sections:
• Ubuntu Software: Configure the types of software packages to download and from where to download them.

• Third-Party Software: Identify non-Ubuntu software repositories from which to retrieve software packages.

• Updates: Define the types of updates to download and how often to check for new updates.

• Authentication: Store public keys for verifying the authenticity of software repositories.

• Statistics: Allow your Ubuntu workstation to share information on the packages you install with an online statistical tracker.

Ubuntu classifies software packages into five categories of software :

Ubuntu Software Repositories
Canonical-supported, opensource software
Large, open-source projects supported by formal organizations, such as OpenOffice.org and Firefox

Community-maintained, opensource software
Smaller, open-source projects, such as GIMP and Rhythmbox, supported by groups of individuals

Proprietary drivers for devices
Drivers supported by a commercial company for its own products only and not released to the open-source community (for example, packages such as video- and sound-card drivers)

Software restricted by copyright or legal issues
Software that may be illegal to use in some countries due to patent or copyright violations

Source code
The application source code for open-source packages

Just select the categories of software you’re interested in keeping up with. By default Ubuntu will retrieve software from all of these repositories. You can remove the check mark next to any of the repositories if you prefer not to use that particular software category. The Updates tab section allows you to customize how your Ubuntu workstation receives software updates. Updates provide a quick and easy way to update an installed software package with new patches that fix coding bugs and security problems. You can control several facets of software updates:

Ubuntu Updates: Select which types of updates to look for in the repositories:

• Security Updates: updates that fix security-related bugs in installed software packages

• Recommended Updates: updates that fix nonsecurity-related code bugs in installed software packages

• Pre-Released Updates: updates that haven’t been officially released by Ubuntu but may fix reported bugs in software

• Unsupported Updates: updates to installed software packages that aren’t supported by the Ubuntu community

• Automatic Updates: Indicate whether the workstation should automatically check for available updates, how often to check, and whether to install security-related updates automatically without notification or user intervention.

• Release Upgrade: Opt to be notified when a new major Ubuntu distribution upgrade has been released.

The updates tab is where you configure Ubuntu to automatically check for updates available in the repositories for the software currently installed on your system. If you have the Update Manager Applet installed an icon appears in the top panel of your desktop notifying you of available updates to download and install. This makes managing software updates a breeze!

As you can see from this list, not only can you update the individual software packages installed on your workstation, you can also perform a complete upgrade from one version of Ubuntu to another via the package download process. This feature is a great timesaver if you have a high-speed Internet connection, because you don’t have to mess with downloading and burning an installation CD. You can upgrade your Ubuntu workstation directly from the Internet.

The software updates allow you to keep an Ubuntu installation active and up to date when the next release becomes available, so there’s no reason to rush out and install a new version when it comes out. However, Ubuntu eventually will cease to release updates for a particular version.

For most distribution versions, Ubuntu provides security and code updates for up to 18 months after the initial release date. The long-term support (LTS) Ubuntu distributions provide security updates for up to 3 years for workstations and 5 years for servers after the distribution release date. When Ubuntu no longer releases security updates for a distribution you can still run the system, but it’s recommended to upgrade to a newer version of Ubuntu to avoid any future security problems.

Source of Information : Wiley Ubuntu Linux Secrets

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