What's the difference between a Long Term Support Release and a Normal Release?

Question

What are the differences between a Ubuntu Long Term Support Release (LTS) and a Normal Release?

Answer 1

There is a new release every 6 months (apart from Dapper, which was delayed 2 months). Every two years, the release is a Long Term Support version.

• Normal releases, server or desktop, are supported for 18 months.

• LTS releases before 12.04 are supported for three years on the desktop and five years on the server.

• LTS releases 12.04 and later are now supported for five years on both the desktop and the server.

  Now, support means:

  • Updates for potential security problems and bugs (not new versions of software)

  • Availability of Commercial support contracts from Canonical

  • Support by Landscape, Canonical's enterprise oriented server management tool set

  The Desktop refers to the packages that are in the main and restricted repositories, these are the ones that have the little Ubuntu icon next to them in Synaptic or are marked as Supported in the Software-Centre respectively.

  The Server packages are the ones in the "server-ship" and "supported-common" seeds (there's a directory of all of the different seeds available).

This is what this looks like:

via the Ubuntu Wiki: LTS

The primary reason for using an LTS release is that you can depend on it being updated regularly and therefore secure and stable.

As you can see from the diagram, people who have installed the 8.04 LTS server don't need to worry about replacing it for still another 2 years! Fantastic. :-)

As if this wasn't enough, Ubuntu release an additional version of the last LTS between releases - such as 8.04.1, that incorporates all of the updates up to this point. This is called a Point-Release (or sometimes snapshot). Those are released every quarter to half year, as needed.

In addition to support, there are Development strategies that differentiate an LTS release:

• The base of the operating system, Debian, comes in three versions: Stable, Testing and Unstable. Normally, Ubuntu is based on Unstable; the LTS releases are based on Testing.

• The Development effort for an LTS release in focussed on providing a rock solid base, not only for customers who want the LTS release, but also for the next Three ubuntu versions to come.

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Thanks to Oli for demystifying that last part, I wasn't quite sure about it.

Answer 2

Support cycle

A LTS gets package updates for supported software for 3 years for desktop packages and 5 years for server packages. Compared to 18 months support for standard releases.

This means you can guarantee a system for a long time. Applications wont jump version so it makes a very solid deployment platform.

Package imports

Ubuntu syncs with debian at the beginning of a new developmeny cycle. On a normal release this pulls in packages from debian-unstable whereas in a LTS cycle, packages come from debian-testing.

These packages have usually had more time with debian and should therefore reflect a better quality product (albeit at the cost of bleeding-edge features).

Development style

There is supposedly more focus on bug fixing for a LTS release, whereas a LTS+1 might focus on adding features, LTS+2 focusses on performance and LTS+3 on stability before rounding it off for the next LTS.

This is less formal than the other points as it's frequently ignored.

Answer 3

Canonical provides security updates for the LTS releases for 3 years on the desktop and 5 years for the server version. The normal release is only supported with updates for 18 months.

Answer 4

Previous desktop LTS releases were supported for 3 years.

However, Ubuntu 12.04 LTS will be supported for 5 years both for desktop and server releases.

Answer 5

Simply put, LTS releases introduce fewer new technologies than Normal releases, and replaces them with Long Term Support of the older, more time-tested technologies that have proven track records of working like said.