Five Things in Fedora This Week (2014-03-25)

[Matthew Miller]

Reposted from
http://fedoramagazine.org/five-things-in-fedora-this-week-2014-03-25/

Fedora is big project, and it’s hard to follow it all. This new feature
will highlight interesting happenings in five different areas every
week. It won’t be comprehensive news coverage — just quick summaries
with links to each. So, here we go for March 25th, 2014:

Snapshot support in virt-manager
--------------------------------

Virt-manager is a GUI for managing virtual machines on your local
system or remotely. It’s handy for intermediate/advanced users or for
sysadmins who are not in the mood for the command line. With version
1.0, now in Rawhide and updates for F20, virt-manager now supports
snapshots. Developer Cole Robinson has a blog post with details and a
walkthrough of the new GUI. (A similar feature may come to Gnome Boxes
in the future via Summer of Code work.)

 * http://virt-manager.org/
 * http://blog.wikichoon.com/2014/03/snapshot-support-in-virt-manager.html
 * http://zee-nix.blogspot.com/2014/03/boxes-312.html


> From upstream code to packages in a repo, automatically every day
-----------------------------------------------------------------

Fedora’s new Copr system lets any Fedora contributor easily maintain
and publish a repository of whatever software you want, as long as it
falls within our legal guidelines. (*cough* Fedora PPAs *cough*) But
what if that’s not automatic enough? What if you want to track a
fast-moving upstream without having to update source RPMs constantly?
Prolific Fedora hacker Pierre-Yves Chibon (“pingou”) presents dgroc,
for “Daily Git Rebuild On Copr”. It basically does just what it says —
takes care of the updating and building in Copr, so you can focus on
the software rather than the packaging.

 * http://copr.fedoraproject.org/
 * http://blog.pingoured.fr/index.php?post/2014/03/20/Introducing-dgroc


Fedora Plasma? A proposal from the KDE SIG
------------------------------------------

The Fedora KDE SIG has been working on a proposal for a Fedora Product
based on KDE Plasma Desktop, with a primary focus on education and
scientific users. Contributor (and board member) Rex Dieter sent the a
request for feedback to the Fedora Advisory Board today; if accepted,
this will join already-planned Cloud, Server, and Workstation products.
The discussion around this will be interesting to follow. Most people
in the project agree that products in the Fedora.next framework should
be held to a high standard, and that we shouldn’t have endless
proliferation, but how, where, and when we draw that line is not
settled.

 * http://fedoraproject.org/wiki/SIGs/KDE
 * https://lists.fedoraproject.org/pipermail/advisory-board/2014-March/01244...

FPL Robyn Bergeron on Fedora, Red Hat, and the Future
-----------------------------------------------------

Fedora Project Leader Robyn Bergeron has a new blog post,
_Fedora, Red Hat, and investing in the future_, with thoughts on Red
Hat’s investment in our project, Fedora’s value to Red Hat, and the
Fedora.next plans.

 * http://robyn.io/2014/03/25/fedora-red-hat-and-investing-in-the-future/


Fedora Atomic
-------------

Since this week has been a little slow, I’m going to cheat a bit and
pull something big from the backlog. Fedora developer Colin Walters has
launched a new project called Fedora Atomic. This system constructs
git-like trees from existing official Fedora RPMs, and moves
operating-system deployment from managing packages to managing these
trees, with (as the name suggests) fully-atomic updates and rollbacks.
It’s still in early development, but moving quickly, and the Fedora
Cloud SIG is considering using it for some special-purpose images
(including a minimal Docker host). Sound interesting — or scary? Learn
more at the links below....

 * http://rpm-ostree.cloud.fedoraproject.org/
 * http://rpm-ostree.cloud.fedoraproject.org/#/background

*****

Thanks to Stephen Gallagher for content suggestions this week, and Joe
Brockmeier for proofreading. If you have tips for the next week, please
send ‘em to me.

-- 
Matthew Miller    --   Fedora Project    --    <mattdm(a)fedoraproject.org&gt;

"Atomic"?? (was Re: Five Things in Fedora This Week (2014-03-25))

[poma]

On 26.03.2014 21:40, Matthew Miller wrote:

>  Old mossbacks should know this one, especially if they have database
> or
>  filesystem experience. An atomic transaction is one which can be safely
>  considered as a single event, and a) failure puts you back as if it didn't
>  happen and b) it is impossible for something else to access whatever is
>  affected and find a partial state -- you either get the original or the
>  update.
>  
>  A normal RPM or yum update is not atomic -- if you pull the plug partway
>  through, or if it breaks for some reason, you are left in a middle state,
>  and, if you access files belonging to packages being updated while the
>  transaction is in progress, you may get surprises.
>  
>  "Partially atomic" usually refers to systems where safe rollbacks happen on
>  failure, but where it might be possible to accidentally make an access while
>  the thing is being changed with unpredictable results.
>   
OK, these are the ancient Greeks' practices.
But, when is Fedora Bosonic ETA?


poma

"Atomic"?? (was Re: Five Things in Fedora This Week (2014-03-25))

[Matthew Miller]

On Wed, Mar 26, 2014 at 08:16:04PM +0000, Beartooth wrote:
>  > pull something big from the backlog. Fedora developer Colin
> Walters has
>  > launched a new project called Fedora Atomic. This system constructs
>  > git-like trees from existing official Fedora RPMs, and moves
>  > operating-system deployment from managing packages to managing these
>  > trees, with (as the name suggests) fully-atomic updates and rollbacks.
>  	Reading that, and following the links, makes it seem that there 
>  is a new buzzword, "atomic" in some sense which may be apparent to those 
>  who use it, but isn't to me. At first, I thought it might be a typo for 
>  "automatic."
>  
>  	Can you define the new Fedora-related sense in terms 
>  comprehensible to old mossbacks? How about partially or "fully-atomic"??
Old mossbacks should know this one, especially if they have database or
filesystem experience. An atomic transaction is one which can be safely
considered as a single event, and a) failure puts you back as if it didn't
happen and b) it is impossible for something else to access whatever is
affected and find a partial state -- you either get the original or the
update.

A normal RPM or yum update is not atomic -- if you pull the plug partway
through, or if it breaks for some reason, you are left in a middle state,
and, if you access files belonging to packages being updated while the
transaction is in progress, you may get surprises.

"Partially atomic" usually refers to systems where safe rollbacks happen on
failure, but where it might be possible to accidentally make an access while
the thing is being changed with unpredictable results.

-- 
Matthew Miller    --   Fedora Project    --    <mattdm(a)fedoraproject.org&gt;

"Atomic"?? (was Re: Five Things in Fedora This Week (2014-03-25))

[Beartooth]

On Tue, 25 Mar 2014 16:31:20 -0400, Matthew Miller wrote:

>  Reposted from
>  http://fedoramagazine.org/five-things-in-fedora-this-week-2014-03-25/ 
	[....]
>  Fedora Atomic -------------
>  
>  Since this week has been a little slow, I’m going to cheat a bit and
>  pull something big from the backlog. Fedora developer Colin Walters has
>  launched a new project called Fedora Atomic. This system constructs
>  git-like trees from existing official Fedora RPMs, and moves
>  operating-system deployment from managing packages to managing these
>  trees, with (as the name suggests) fully-atomic updates and rollbacks. 
	Reading that, and following the links, makes it seem that there 
is a new buzzword, "atomic" in some sense which may be apparent to those 
who use it, but isn't to me. At first, I thought it might be a typo for 
"automatic."

	Can you define the new Fedora-related sense in terms 
comprehensible to old mossbacks? How about partially or "fully-atomic"??

-- 
Beartooth Staffwright, Neo-Redneck Not Quite Clueless Power User
Remember I have precious (very precious!) little idea where up is.

"Atomic"?? (was Re: Five Things in Fedora This Week (2014-03-25))

[Cameron Simpson]

On 26Mar2014 20:16, Beartooth <beartooth(a)comcast.net&gt; wrote:
>  On Tue, 25 Mar 2014 16:31:20 -0400, Matthew Miller wrote:
>  > Reposted from
>  > http://fedoramagazine.org/five-things-in-fedora-this-week-2014-03-25/
>  	[....]
>  > Fedora Atomic -------------
>  > 
>  > Since this week has been a little slow, I’m going to cheat a bit and
>  > pull something big from the backlog. Fedora developer Colin Walters has
>  > launched a new project called Fedora Atomic. This system constructs
>  > git-like trees from existing official Fedora RPMs, and moves
>  > operating-system deployment from managing packages to managing these
>  > trees, with (as the name suggests) fully-atomic updates and rollbacks.
>  
>  	Reading that, and following the links, makes it seem that there 
>  is a new buzzword, "atomic" in some sense which may be apparent to those 
>  who use it, but isn't to me. At first, I thought it might be a typo for 
>  "automatic."
>  
>  	Can you define the new Fedora-related sense in terms 
>  comprehensible to old mossbacks? How about partially or "fully-atomic"??
"atomic" is a very old term, even in computing.

It mean indivisible, and is why atoms are called atoms.

In computing, it means any change which does now expose any itermediate
steps: before the change you have state 1, and after the change you
have state 2.

As an example, for a single file update a common practice is to
write the new file to a temporary name, and then rename the completed
temporary file to the original. POSIX guarentees that that is atomic:
before the rename opening the original name gets you the old file,
and after the rename opening the original name gets your the new
file, and there is no gap in the middle where the original name
doesn't work.

When you run RPM, a lot of files get replaced or modified. in place
in your live running OS.

The atomic project is a system for preparing all those changes off to the
side and then cutting over in one go. Likewise for rolling back.

Cheers,
-- 
Cameron Simpson <cs(a)zip.com.au&gt;

Sorry, baby, I can't take you to the pizza joint tonight, I've got to go
back to the lab and split the atom.     - Ayn Rand, "What is Romanticism?"