PowerPCReview

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PowerPC, already a significantly less mainstream architecture than x86(-64), has seen it's visibility further reduced by the fact that Apple, the primary source of consumer PowerPC hardware, has moved away from the platform. Ubuntu needs to decide whether PowerPC should continue as a fully supported platform for the feisty release. PowerPC, already a significantly less mainstream architecture than x86(-64), has seen its visibility further reduced by the fact that Apple, the primary source of consumer PowerPC hardware, has moved away from the platform. Ubuntu needs to decide whether PowerPC should continue as a fully supported platform for the feisty release.
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  * In July 2005, PowerPC represented 1.95% of downloads from archive.ubuntu.com. In only 15 months (i.e. to November 2006) that number has declined to 0.8%.   * In July 2005, PowerPC represented 1.95% of downloads from archive.ubuntu.com (this figure is more or less the percentage of the current user base performing upgrades). In only 15 months (i.e. to November 2006) that number has declined to 0.8%.
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  * Sony's PS3 is PowerPC based and will support running Linux. '''It will be a modern et powerfull platform, easily available for end-users.'''   * The new Intel-based Macs are [https://features.launchpad.net/distros/ubuntu/+spec/intel-mac-support not yet supported], so this risks leaving loyal Apple users out in the cold until that is fixed.
* Sony's PS3 is PowerPC based and will support running Linux. '''It will be a modern and powerful platform, easily available for end users.'''
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  * [http://www.genesippc.com/products.php GenesisPPC] did sell more pre-installed ubuntu-system than Dell in 2005.
  * iMacs are a major platform used in schools, at least for edubuntu and LTSP ppc support should still persist for a while in ubuntu.
  * [http://www.genesippc.com/products.php GenesisPPC] sold more pre-installed Ubuntu systems than Dell in 2005.
  * iMacs are a major platform used in schools; at least for Edubuntu and LTSP, PowerPC support should continue for a while.
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The former is complicated by the fact that the current archive/ports split is achieved by a simple list of rsync exclude and includes. If feisty PowerPC moves to ports.ubuntu.com, the split process would have to become signficantly more intelligent (e.g. by parsing the Packages and Sources files to determine what files need to be copied across and/or excluded). The former is complicated by the fact that the current archive/ports split is achieved by a simple list of rsync exclude and includes. If feisty PowerPC moves to ports.ubuntu.com, the split process would have to become significantly more intelligent (e.g. by parsing the Packages and Sources files to determine what files need to be copied across and/or excluded).
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 * The relative size of the existing user base is already addressed by the figures from archive.ubuntu.com. The CD image download figures were intended to address new installs only. I've clarified this above. --ColinWatson
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 * These tests are presently entirely manual. We are working separately on automating some of them, but they still consume a very large amount of core development team time just before each release (including milestone releases, etc.). Furthermore, the lack of support for Xen on powerpc makes certain kinds of automatic testing more difficult. You brush off 40GB of disk space but it's actually a fairly major issue for some of our mirrors; note that Ubuntu shares space with other distributions on many mirrors and additional tens of gigabytes mean that they have to make hard choices and/or buy new disks for machines that are often already physically maxed out and cannot easily be upgraded without significant expenditure. --ColinWatson

Please check the status of this specification in Launchpad before editing it. If it is Approved, contact the Assignee or another knowledgeable person before making changes.

Summary

PowerPC, already a significantly less mainstream architecture than x86(-64), has seen its visibility further reduced by the fact that Apple, the primary source of consumer PowerPC hardware, has moved away from the platform. Ubuntu needs to decide whether PowerPC should continue as a fully supported platform for the feisty release.

Rationale

  • Reasons against keeping PowerPC as a fully supported architecture:
    • In July 2005, PowerPC represented 1.95% of downloads from archive.ubuntu.com (this figure is more or less the percentage of the current user base performing upgrades). In only 15 months (i.e. to November 2006) that number has declined to 0.8%.
    • In January of 2006 Apple started switching from PowerPC to Intel and by August 2006 its entire consumer line had switched away from the PowerPC architecture. That leaves people with (as good as) no access to new consumer level desktop or laptop PowerPC based hardware.
    • PowerPC represented 3.3% of CD downloads from releases.ubuntu.com for dapper but only 2.7% of CD downloads for edgy.
    • Testing an Ubuntu release involves a complex testing process that currently involves testing 22 variations for each architecture. Fully supporting PowerPC means the full 22 variations have to be tested which is a strain on available resources especially since testing requires physical access to hardware, much of which is no longer on sale.
    • archive.ubuntu.com and releases.ubuntu.com are mirrored by hundreds of mirrors worldwide. Each architecture increases the total size of the archive and the size of updates sent to all these mirrors everyday.
      • Overall size of PowerPC on archive.ubuntu.com: 27Gb (15% of total size)
      • Overall size of PowerPC on releases.ubuntu.com: 9.2Gb (32% of total size)
    • PowerPC currently provides no production-level virtualization support to the degree we require for PPA (PersonalPackageArchives) or Grumpy. This makes it harder for community members without access to PowerPC hardware to support the port.

    • Several of the PowerPC specific tools (e.g. yaboot) are essentially unmaintained and trying to keep them (and the PowerPC) port current with new technologies (e.g. gfxboot) is difficult and time consuming.
  • Reasons for keeping PowerPC as a fully supported architecture:
    • When Apple EOL support for their PowerPC based machines, there'll be several knock on effects:
      • Existing Apple users may choose to migrate to Ubuntu so they can continue to use a supported OS
      • Existing Ubuntu users may be able to pick up second hand PowerPC hardware very cheaply
        • Both of these may lead to an increase in demand for the PowerPC port.
    • The new Intel-based Macs are [https://features.launchpad.net/distros/ubuntu/+spec/intel-mac-support not yet supported], so this risks leaving loyal Apple users out in the cold until that is fixed.

    • Sony's PS3 is PowerPC based and will support running Linux. It will be a modern and powerful platform, easily available for end users.

    • IBM's OpenPower platform ensures that powerpc remains a viable Linux platform on the server

    • There are some existing IHVs (e.g Genesi) producing powerpc based consumer hardware
    • [http://www.power.org/ power.org] exist to try encourage further IHV powerpc based consumer hardware

    • Xen is being worked on, however it requires hardware assist and only certain types of PowerPC hardware are suitable (notably, Apple Hardware and OpenPOWER servers are not).
    • [http://www.genesippc.com/products.php GenesisPPC] sold more pre-installed Ubuntu systems than Dell in 2005.

    • iMacs are a major platform used in schools; at least for Edubuntu and LTSP, PowerPC support should continue for a while.

Use cases

Scope

This specification is limited in scope in the following ways:

  • It only considers the future of the PowerPC port for the feisty release. This specification will need to be revisited for feisty+1.
  • Removal of the PowerPC port entirely is not under consideration.

Design

Implementation

There are three possible alternative implementations:

  • PowerPC remains a fully supported platform
  • PowerPC becomes a 'supported on the server only' platform (like Sparc)
  • PowerPC becomes a community supported platform (like PA-RISC and Itanium)

Code

Data preservation and migration

If PowerPC becomes a community supported platform and moves to ports.ubuntu.com, there will be some some migration issues.

  • Migration of feisty only for PowerPC to ports.ubuntu.com while retaining edgy and earlier releases on archive.ubuntu.com

  • Changes necessary to debian-installer and other packages to adjust for powerpc being on ports.ubuntu.com rather than archive.ubuntu.com

The former is complicated by the fact that the current archive/ports split is achieved by a simple list of rsync exclude and includes. If feisty PowerPC moves to ports.ubuntu.com, the split process would have to become significantly more intelligent (e.g. by parsing the Packages and Sources files to determine what files need to be copied across and/or excluded).

Unresolved issues

The fundamental decision remains undecided.

BoF agenda and discussion

["Warbo"]: Since 6.06 has long term support it might be a viable option to not port Feisty to PowerPC, since Dapper will still be supported. The server issue is similar, since Dapper is more of a server-focused release than Edgy or Feisty. Admittedly I think one of the great advantages of Free Software like Ubuntu is not being tied to a single architecture (x86), but with the current situation I think that only supporting PowerPC with LTS will produce more useful results for x86 users, and as PowerPC-based devices enter more and more homes (mainly as consoles) and GNU/Linux systems become easier to install and use on them then the situation can be revised to take advantage of this untapped userbase. Mind you, perhaps Ubuntu is not suitable for console systems at all and we should try not to let Ubuntu's influence and popularity stifle new distros with a narrower focus on that area.

["KeywanNajafiTonekaboni"]: I am a PowerPC User and find some points in your list against PowerPC-support not fair.

You point to the less downloaded CD Images of Edgy for PowerPC. I download breezy for my iBook one time. I installed Ubuntu and never again download a CD Image again. I am using Ubuntu Edgy now and uploaded every Version with apt-get. You also encoureged users to stay by Dapper, because edgy is more experimantel then the releases before.

  • The relative size of the existing user base is already addressed by the figures from archive.ubuntu.com. The CD image download figures were intended to address new installs only. I've clarified this above. --ColinWatson

The other "fact is, that you can't buy PowerPC Hardware from Apple anymore. You can still buy PowerPC based Hardware on eBay etc for testing (or using). Richard Hughes, the developer behind the awesome Gnome Power Manager, bought a broken iBook G3 "Clamshell" to discover the PMU (PowerManagementUnit) and support it.

Dapper is LTS, that's true. And edgy supports PowerPC, but I don't want to stick with GNOME 2.16. If I like that, I still would using Debian Wink ;)

Please don't drop the support for PowerPC. I think they are a lot of People using their iMacs, iBooks and don't like or have the money to throw they old computers away and buy new hardware. And it's just one year ago Apple dropped their Hardware. Can't you wait at least one or two releases?

And a last question: How much time and money you would really save, by dropping the support. 40GB HD space is nothing. 22 test sounds a lot, but are they automated etc. How much attention need this test?

  • These tests are presently entirely manual. We are working separately on automating some of them, but they still consume a very large amount of core development team time just before each release (including milestone releases, etc.). Furthermore, the lack of support for Xen on powerpc makes certain kinds of automatic testing more difficult. You brush off 40GB of disk space but it's actually a fairly major issue for some of our mirrors; note that Ubuntu shares space with other distributions on many mirrors and additional tens of gigabytes mean that they have to make hard choices and/or buy new disks for machines that are often already physically maxed out and cannot easily be upgraded without significant expenditure. --ColinWatson

Ubuntu Forum PPC Users discussion thread

http://ubuntuforums.org/showthread.php?t=298746


CategorySpec

PowerPCReview (last edited 2008-08-06 16:18:55 by localhost)