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Building a Hackerspace

A lot of good things are going on lately. Last weekend I was in Nuremberg for the openSUSE Board f2f meeting which when more than fine. I am preparing for oSC15 and on the openSUSE Camp things are better than usual.

We spent a few months talking about making a Hackerspace in Thessaloniki and almost a couple of months some people decided to stop talking and start acting. So we made Tech Ministry , a 180 square meters place in the center of Thessaloniki where everybody can find a home for their projects. Of course we are still building it, literally a hackerspace is never over, but we still need a few things to make it functional. We plan to have it fully functional but the end of next week, but I know really well that everybody has a plan until they get hit, LoL.
If you have some money left in your paypal and you want to help you can do it by donating to our Hackerspace here. We could also use any kind of equipment that you don't need so all you have to do is contact me here by sending a comment or by sending me an email. If you are an FOSS Project Tech Ministry is always happy to support you by promoting your project in our members, so just send us all the information you think we will need for that. 
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What DAW (or other music software) is the right for me?

Dear lazyweb,

Is Ableton Live the right DAW for me?

I am not a musician or "producer". I don't know how to play any instrument. I don't really know musical notation (and have little desire to learn). But I do have some basic understanding of musical theory, an open mind, and would enjoy making experimental music. The kind I like to listen to. (Or, for the matter, why not more traditional electronic music, even dancey stuff, too.)

(I do listen to more "normal" music, too, not just experimental bleeps and drones;)

Among my favourite composers / artists are the usual suspects like Scelsi, Ligeti, Reich, Glass, Eno, Fripp, Kraftwerk, and contemporary ones like Max Richter, Anna Thorvaldsdottir, Nils Frahm, and of course acts like Circlesquare, Monolake, Plastikman etc. My favourite radio show is WNYC's New Sounds .

The software I have been ogling most is Ableton Live. What I like about it is that it is popular, cool, and has a thriving development, apparently, with relatively frequent updates etc. It seems not likely to go away suddenly. I love the total (?) lack of skeuomorphism in the user interface. (I strongly dislike the trend of faux real hardware look and feel in 3rd-party plugins.)

I certainly have no wish to use the "live" aspect of Live. And, as one of the main points, as I understand it, of Live is to make it easy to launch clips that will be automatically properly aligned in live performance scenarios, will Live be suitable for stuff like having multiple loops or patterns playing simultaneously *without* being synchronised? You know, like emulating Frippertronics, or patterns being slightly out of phase in the style of Reich, or Eno.

And what about microtonal aspects?

So, will Live have too many limitations? Should I look somewhere else? Maybe the generative music scene is what I should be looking into, like Intermorphic's Noatikl? Although with that I would definitely be afraid of the proprietary-software-maker-goes-belly-up scenario.

Maybe even some Open Source software? Csound? Pd? Note that I wouldn't want to get lured into hacking (programming) on some Open Source software, for once I want to be "just a user"...

Oh, and I use a Mac as my desktop environment, so that is also a limiting factor.

Or am I silly to even think I could create something interesting (to myself, that is) without starting by learning how to do stuff "by the book" first?

--tml

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darix posted at

GitLab CE Quick install for our rpm

General

Official Install Documentation

Repositories

  1. use the repositories from devel:languages:ruby and home:darix:apps
  2. zypper in –from home:darix:apps redis gitlab-ce gitlab-shell

config redis:

See also: /usr/share/doc/packages/redis/README.SUSE

$ cd /etc/redis
$ cp default.conf.example gitlab.conf
$ vi gitlab.conf

* daemonize no
* pidfile /var/run/redis/gitlab.pid
* logfile /var/log/redis/gitlab.log
* dir /var/lib/redis/gitlab/

$ install -d -m 0750 -o redis -g redis /var/lib/redis/gitlab/
$ chown root:redis gitlab.conf
$ sc start redis@gitlab
$ sc enable redis@gitlab

GitLab Shell

  1. cd /usr/share/gitlab/shell/; cp config.yml{.example,}
  2. set up redis socket matching /etc/redis/gitlab.conf
  3. maybe enable audit_usernames (but see warning)

config rails app

  1. cd /srv/www/vhosts/gitlab-ce/
  2. configure database.yml (based on postgresql example)
  3. cp config/gitlab.yml.{example,}
  • host, port, https, email_from in gitlab section
  • optionally ldap settings
  1. cp config/resque.yml.{example,}
  • adapt socket for redis. should match /etc/redis/gitlab.conf
  1. export RAILS_ENV="${RAILS_ENV:=production}"
  2. gitlab-ce-update
  3. rake db:seed_fu
  4. check for new files which are now owned by root:root (e.g. .gitlab_shell_secret) they should be owned by root:gitlab with permissions u=rw,g=r,o=
  5. make sure you have the symlink .gitlab_shell_secret /srv/www/vhosts/gitlab-ce/.gitlab_shell_secret
  6. Configure git for gitlab user as seen in official docs
  7. sc start gitlab-ce-unicorn gitlab-ce-sidekiq gitlab-workhorse
  8. sc enable gitlab-ce-unicorn gitlab-ce-sidekiq gitlab-workhorse

Testing things

  1. ssh access
ssh -T gitlab@gitlab.suse.de
Welcome to GitLab, $yourusername!
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UnReal World RPG and propiertary applications in linux ecosystem part SDL2 take 2

My opinion is Simple Direct Layer 2  library is awesome piece of code. SDL2 delivers 99.9% what it promises. When SDL2 works it makes good habit to stay away your mind but now I want to talk about when SDL2 doesn’t work and when you want to deliver closed source application.

It seems that there is some problems with  OpenGL/DirectX and other accelerations APIs that they don’t play together without tweaking and researching ways to make them work. Okay this ain’t SDL2 fault completely this manufacturer problem again but.. you use SDL2 to get rid of hardware problems.

All those problems are solvable with current SDL2 version but again they takes lots of time and someone who is willing to debug application in non-working machine and remember this is normal stuff in development and not a big thing. But it’s big thing when you are about to releasing your new bling bling game with megalomanic blitting and your surfaces starts to blink every time you blit with some random machines. Even in not so bling bling UnReal Wolrd RPG you have problem with that but they are solved now but I builded many many Mac OS X and Linux builds before problem was traced to SDL2 related. If you are Apple people I point my finger to you. What the heck you are doing to openGL in Mac OS X??

SDL2 is what open source library but their biggest problems (in my opinion) are these: Hey Wiki is nice but have proper Doxygen or something documentation (which should be official), You have Bugzilla but there is no connection (or I just didn’t noticed) how bugs and Mercurial repository communicate each other and where/how you communicate with you users (mailinglists are so 90′ how about posting some news)?

What this leads is people post patches to Bugzilla where they get to nowhere and other one are using them because they solve their problem. This leads in situation where there is unofficial SDL2 libraries that are not compatible with each other. This is normal situation in open source world and SDL2 is under ZLib license so you can do it but what happens when they fix something that was broken to official SDL2 library and you using older one in development that is patched to work?

This is not SDL2 specific thing it’s very common situation with many open source projects (and yes they tend to have limited man power if you like to fix them you can! Learn to communicate with those people like I should with SDL2 people) but in a way SDL2 have deep connection with Valve (They use it in Linux steam client at least) and Steam ain’t small company they should but power behind this or let it go.

At the end remember this ain’t rant against SDL2 or SDL2 developers. They are doing hard work for you getting mostly nothing out of it. Because Eastern is all about pain and unhappiness so this was my contribution to that or no not really people!! Life is too short for sadness so have a lot’s of fun all eastern!

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Limba Project: Another progress report

And once again, it’s time for another Limba blogpost 🙂limba-small

Limba is a solution to install 3rd-party software on Linux, without interfering with the distribution’s native package manager. It can be useful to try out different software versions, use newer software on a stable OS release or simply to obtain software which does not yet exist for your distribution.

Limba works distribution-independent, so software authors only need to publish their software once for all Linux distributions.

I recently released version 0.4, with which all most important features you would expect from a software manager are complete. This includes installing & removing packages, GPG-signing of packages, package repositories, package updates etc. Using Limba is still a bit rough, but most things work pretty well already.

So, it’s time for another progress report. Since a FAQ-like list is easier to digest. compared to a long blogpost, I go with this again. So, let’s address one important general question first:

How does Limba relate to the GNOME Sandboxing approach?

(If you don’t know about GNOMEs sandboxes, take a look at the GNOME Wiki – Alexander Larsson also blogged about it recently)

First of all: There is no rivalry here and no NIH syndrome involved. Limba and GNOMEs Sandboxes (XdgApp) are different concepts, which both have their place.

The main difference between both projects is the handling of runtimes. A runtime is the shared libraries and other shared ressources applications use. This includes libraries like GTK+/Qt5/SDL/libpulse etc. XdgApp applications have one big runtime they can use, built with OSTree. This runtime is static and will not change, it will only receive critical security updates. A runtime in XdgApp is provided by a vendor like GNOME as a compilation of multiple single libraries.

Limba, on the other hand, generates runtimes on the target system on-the-fly out of several subcomponents with dependency-relations between them. Each component can be updated independently, as long as the dependencies are satisfied. The individual components are intended to be provided by the respective upstream projects.

Both projects have their individual up and downsides: While the static runtime of XdgApp projects makes testing simple, it is also harder to extend and more difficult to update. If something you need is not provided by the mega-runtime, you will have to provide it by yourself (e.g. we will have some applications ship smaller shared libraries with their binaries, as they are not part of the big runtime).

Limba does not have this issue, but instead, with its dynamic runtimes, relies on upstreams behaving nice and not breaking ABIs in security updates, so existing applications continue to be working even with newer software components.

Obviously, I like the Limba approach more, since it is incredibly flexible, and even allows to mimic the behaviour of GNOMEs XdgApp by using absolute dependencies on components.

Do you have an example of a Limba-distributed application?

Yes! I recently created a set of package for Neverball – Alexander Larsson also created a XdgApp bundle for it, and due to the low amount of stuff Neverball depends on, it was a perfect test subject.

One of the main things I want to achieve with Limba is to integrate it well with continuous integration systems, so you can automatically get a Limba package built for your application and have it tested with the current set of dependencies. Also, building packages should be very easy, and as failsafe as possible.

You can find the current Neverball test in the Limba-Neverball repository on Github. All you need (after installing Limba and the build dependencies of all components) is to run the make_all.sh script.

Later, I also want to provide helper tools to automatically build the software in a chroot environment, and to allow building against the exact version depended on in the Limba package.

Creating a Limba package is trivial, it boils down to creating a simple “control” file describing the dependencies of the package, and to write an AppStream metadata file. If you feel adventurous, you can also add automatic build instructions as a YAML file (which uses a subset of the Travis build config schema)

This is the Neverball Limba package, built on Tanglu 3, run on Fedora 21:

Limba-installed Neverball

Which kernel do I need to run Limba?

The Limba build tools run on any Linux version, but to run applications installed with Limba, you need at least Linux 3.18 (for Limba 0.4.2). I plan to bump the minimum version requirement to Linux 4.0+ very soon, since this release contains some improvements in OverlayFS and a few other kernel features I am thinking about making use of.

Linux 3.18 is included in most Linux distributions released in 2015 (and of course any rolling release distribution and Fedora have it).

Building all these little Limba packages and keeping them up-to-date is annoying…

Yes indeed. I expect that we will see some “bigger” Limba packages bundling a few dependencies, but in general this is a pretty annoying property of Limba currently, since there are so few packages available you can reuse. But I plan to address this. Behind the scenes, I am working on a webservice, which will allow developers to upload Limba packages.

This central ressource can then be used by other developers to obtain dependencies. We can also perform some QA on the received packages, map the available software with CVE databases to see if a component is vulnerable and publish that information, etc.

All of this is currently planned, and I can’t say a lot more yet. Stay tuned! (As always: If you want to help, please contact me)

Are the Limba interfaces stable? Can I use it already?

The Limba package format should be stable by now – since Limba is still Alpha software, I will however, make breaking changes in case there is a huge flaw which makes it reasonable to break the IPK package format. I don’t think that this will happen though, as the Limba packages are designed to be easily backward- and forward compatible.

For the Limba repository format, I might make some more changes though (less invasive, but you might need to rebuilt the repository).

tl;dr: Yes! Plase use Limba and report bugs, but keep in mind that Limba is still in an early stage of development, and we need bug reports!

Will there be integration into GNOME-Software and Muon?

From the GNOME-Software side, there were positive signals about that, but some technical obstancles need to be resolved first. I did not yet get in contact with the Muon crew – they are just implementing AppStream, which is a prerequisite for having any support for Limba[1].

Since PackageKit dropped the support for plugins, every software manager needs to implement support for Limba.


So, thanks for reading this (again too long) blogpost 🙂 There are some more exciting things coming soon, especially regarding AppStream on Debian/Ubuntu!

 

[1]: And I should actually help with the AppStream support, but currently I can not allocate enough time to take that additional project as well – this might change in a few weeks. Also, Muon does pretty well already!

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High Contrast Refresh

One of the major visual updates of the 3.16 release is the high contrast accessible theme. Both the shell and the toolkit have received attention in the HC department. One noteworthy aspect of the theme is the icons. To guarantee some decent amount of contrast of an icon against any background, back in GNOME 2 days, we solved it by "double stroking" every shape. The term double stroke comes from a special case, when a shape that was open, having only an outline, would get an additional inverted color outline. Most of the time it was a white outline of a black silhouette though.

Old HC theme
Fuzzy doublestroke PNGs of the old HC theme

In the new world, we actually treat icons the same way we treat text. We can adjust the best contrast by controlling the color at runtime. We do this the same way we've done it for symbolic icons, using an embedded CSS stylesheet inside SVG icons. And in fact we are using the very same symbolic icons for the HC variant. You would be right arguing that there are specific needs for high contrast, but in reality majority of the double stroked icons in HC have already been direct conversions of their symbolic counterparts.

New HC theme
Crisp recolorable SVGs of the post 3.16 world

While centralized theme that overrides all application never seemed like a good idea, as the application icon is part of its identity and should be distributed and maintained alongside the actual app, the process to create a high contrast variant of an icon was extremely cumbersome and required quite a bit of effort. With the changes in place for both the toolkit and the shell, it's far more reasonable to mandate applications to include a symbolic/high contrast variant of its app icon now. I'll be spending my time transforming the existing double stroke assets into symbolic, but if you are an application author, please look into providing a scalable stencil variant of your app icon as well. Thank you!

the avatar of Jeffrey Stedfast

Code Review: Microsoft's System.Net.Mail Implementation

For those reading my blog for the first time and don't know who I am, allow myself to introduce... myself.

I'm a self-proclaimed expert on the topic of email, specifically MIME, IMAP, SMTP, and POP3. I don't proclaim myself to be an expert on much, but email is something that maybe 1 or 2 dozen people in the world could probably get away with saying they know more than I do and actually back it up. I've got a lot of experience writing email software over the past 15 years and rarely do I come across mail software that does things better than I've done them. I'm also a critic of mail software design and implementation.

My latest endeavors in the email space are MimeKit and MailKit, both of which are open source and available on GitHub for your perusal should you doubt my expertise.

My point is: I think my review carries some weight, or I wouldn't be writing this.

Is that egotistical of me? Maybe a little.

I was actually just fixing a bug in MimeKit earlier and when I went to go examine Mono's System.Net.Mail.MailMessage implementation in order to figure out what the problem was with my System.Net.Mail.MailMessage to MimeKit.MimeMessage conversion, I thought, "hey, wait a minute... didn't Microsoft just recently release their BCL source code?" So I ended up taking a look and pretty quickly confirmed my suspicions and was able to fix the bug.

When I begin looking at the source code for another mail library, I can't help but critique what I find.

MailAddress and MailAddressCollection


Parsing email addresses is probably the hardest thing to get right. It's what I would say makes or breaks a library (literally). To a casual onlooker, parsing email addresses probably seems like a trivial problem. "Just String.Split() on comma and then look for those angle bracket thingies and you're done, right?" Oh God, oh God, make the hurting stop. I need to stop here before I go into a long rant about this...

Okay, I'm back. Blood pressure has subsided.

Looking at MailAddressParser.cs (the internal parser used by MailAddressCollection), I'm actually pleasantly surprised. It actually looks pretty decent and I can tell that a lot of thought and care went into it. They actually use a tokenizer approach. Interestingly, they parse the string in reverse which is a pretty good idea, I must say. This approach probably helps simplify the parser logic a bit because parsing forward makes it difficult to know what the tokens belong to (is it the name token? or is it the local-part of an addr-spec? hard to know until I consume a few more tokens...).

For example, consider the following BNF grammar:

address         =       mailbox / group
mailbox         =       name-addr / addr-spec
name-addr       =       [display-name] angle-addr
angle-addr      =       [CFWS] "<" addr-spec ">" [CFWS] / obs-angle-addr
group           =       display-name ":" [mailbox-list / CFWS] ";"
                        [CFWS]
display-name    =       phrase
word            =       atom / quoted-string
phrase          =       1*word / obs-phrase
addr-spec       =       local-part "@" domain
local-part      =       dot-atom / quoted-string / obs-local-part
domain          =       dot-atom / domain-literal / obs-domain
obs-local-part  =       word *("." word)

Now consider the following email address: "Joe Example" <joe@example.com>

The first token you read will be "Joe Example" and you might think that that token indicates that it is the display name, but it doesn't. All you know is that you've got a 'quoted-string' token. A 'quoted-string' can be part of a 'phrase' or it can be (a part of) the 'local-part' of the address itself. You must read at least 1 more token before you'll be able to figure out what it actually is ('obs-local-part' makes things slightly more difficult). In this case, you'll get a '<' which indicates the start of an 'angle-addr', allowing you to assume that the 'quoted-string' you just got is indeed the 'display-name'.

If, however, you parse the address in reverse, things become a little simpler because you know immediately what to expect the next token to be a part of.

That's pretty cool. Kudos to the Microsoft engineers for thinking up this strategy.

Unfortunately, the parser does not handle the 'group' address type. I'll let this slide, however, partly because I'm still impressed by the approach the address parser took and also because I realize that System.Net.Mail is meant for creating and sending new messages, not parsing existing messages from the wild.

Okay, so how well does it serialize MailAddress?

Ugh. You know that face you make when you just see a guy get kicked in the nuts? Yea, that's the face I made when I saw line #227:

encodedAddress = String.Format(CultureInfo.InvariantCulture, "\"{0}\"", this.displayName);

The problem with the above code (and I'll soon be submitting a bug report about this) is that the displayName string might have embedded double quotes in it. You can't just surround it with quotes and expect it to work. This is the same mistake all those programmers make that allow SQL-injection attacks.

For an example of how this should be done, see MimeKit's MimeUtils.Quote() method.

I had such high hopes... at least this is a fairly simple bug to fix. I'll probably just offer them a patch.

ContentType and ContentDisposition


Their parser is decent but it doesn't handle rfc2231 encoded parameter values, so I'm not overly impressed. It'll get the job done for simple name="value" parameter syntax, though, and it will decode the values encoded with the rfc2047 encoding scheme (which is not the right way to encode values, but it is common enough that any serious parser should handle it). The code is also pretty clean and uses a tokenizer approach, so that's a plus. I guess since this isn't really meant as a full-blown MIME parser, they can get away with this and not have it be a big deal. Fair enough.

Serialization, unsurprisingly, leaves a lot to be desired. Parameter values are, as I expected, encoded using rfc2047 syntax rather than the IETF standard rfc2231 syntax. I suppose that you could argue that this is for compatibility, but really it's just perpetuating bad practices. It also means that it can't properly fold long parameter values because the encoded value just becomes one big long encoded-word token. Yuck.

Base64


Amusingly, Microsoft does not use their Convert.FromBase64() decoder to decode base64 in their System.Net.Mail implementation. I point this out mostly because it is the single most common problem users have with every one of the Open Source .NET mail libraries out there (other than MimeKit, of course) because Convert.FromBase64() relies on the data not having any line breaks, white space, etc in the input stream.

This should serve as a big hint to you guys writing your own .NET email libraries not to use Convert.FromBase64() ;-)

They use unsafe pointers, just like I do in MimeKit, but I'm not sure how their performance compares to MimeKit's yet. They do use a state machine, though, so rock on.

I approve this base64 encoder/decoder implementation.

SmtpClient


One thing they do which is pretty cool is connection pooling. This is probably a pretty decent win for the types of things developers usually use System.Net.Mail's SmtpClient for (spam, anyone?).

The SASL AUTH mechanisms that they seem to support are NTLM, GSSAPI, LOGIN and WDIGEST (which apparently is some sort of IIS-specific authentication mechanism that I had never heard of until now). For those that were curious which SASL mechanisms SmtpClient supported, well, now you know.

The code is a bit hard to follow for someone not familiar with the codebase (not nearly as easy reading as the address or content-type parsers, I'm afraid), but it seems fairly well designed.

It does not appear to support PIPELINING or BINARYMIME like MailKit does, though. So, yay! Win for MailKit ;-)

They do support SMTPUTF8, so that's good.

It seems that if you set client.EnableSsl to true, it will also try STARTTLS if it isn't able to connect on the SSL port. I wasn't sure if it did that or not before, so this was something I was personally interested in knowing.

Hopefully my SmtpClient implementation review isn't too disappointing. I just don't know what to say about it, really. It's a pretty straight-forward send-command-wait-for-reply implementation and SMTP is pretty dead simple.

Conclusion


Overall the bits I was interested in were better than I expected they'd be. The parsers were pretty good (although incomplete) and the serializers were "good enough" for normal use.

Of course, it's not as good as MimeKit, but let's be honest, MimeKit sets the bar pretty high ;-)

the avatar of Andrés G. Aragoneses

How do you upgrade your distro? A tale of two workarounds

Every classic Linuxer would know why it's very handy to dedicate a separate partition for the /home folder of your tree: you could in theory share it between multiple OSs that you installed in your box (which you choose to run when you start your computer).

Now, I'm guessing that many people reading and nodding to the above, will also know that sharing /home/ is one thing, sharing $HOME (/home/yourUserName) is a completely different beast.

For example: you have a stable distro installed in your box; you decide to install a new version of that distro along the old one, in the same box. You run the new distro with a new account tied to the old /home/yourUserName folder: KABOOM!!! Weird things start happening. Among these:

  • The newer versions of your desktop or desktop programs don't run properly with the settings saved in your .dotDirectories (they are to blame because they didn't probably have a settings-conversion feature).
  • The newer versions of your desktop or desktop programs have a buggy settings-conversion feature; because your program does not run properly, or as well as it would have run if it had been ran for the first time with no settings saved at all.
  • The newer versions of your non-buggy desktop or desktop programs convert your settings to a new format. Then when you go back and run your old distro again, your old-versioned programs stop working because they see settings in a new format which they don't understand. (This is impossible to fix, or very hard.) It's very important that this scenario works, because the migration to the new version of your distro may not be immediate, it may take you some days to figure everything out, and until that happens, you want to still be able to run the stable version of your desktop and desktop programs
  • Etc.

To workaround these problems, I have a strategy: I use a different /home/ sub-directory for each distro installed in my system. For example, for distro X version A.B I use /home/knocteXAB/, for distro Y version C.D I use /home/knocteYCD/. The advantage about this is that you can migrate your settings manually and at your own pace. But then, you may be asking, how to really take advantage of sharing the /home folder when using this technique?

Easy: I keep non-settings data (mainly the non-dotfiles) in a different /home/ folder with no associated account in any of the distros. For example: /home/knocte/ (no version suffix). Then, from each of the suffixed /home/ subfolders, I setup symlinks to this other folder, setting the appropriate permissions. For instance:

  • /home/knocteXAB/Music -> /home/knocte/Music
  • /home/knocteXAB/Documents -> /home/knocte/Documents
  • /home/knocteYCD/Music -> /home/knocte/Music
  • /home/knocteYCD/Documents -> /home/knocte/Documents
  • Etc.
You may think that it's an interesting strategy and that I'm done with the blog post, however, when using this strategy you may start finding buggy applications that don't deal very well with symlinked paths. The one I found which annoyed the most was my favourite Gnome IDE, because it meant I couldn't develop software without problems. I mean, they were not just cosmetic problems, really:

So I had to use a workaround for my workaround: clone all my projects in $HOME instead of /home/knocte/Documents/Code/OpenSource/ (yah, I'm this organized ;) ).

I've been trying to fix these problems for a while, without much time on my hands.

But the last weeks a magical thing happened: I decided to finally sit down and try to fix the last two remaining, and my patches were all accepted and merged last week! (at least all the ones fixing symlink-related problems), woo!!!

So the lessons to learn here are:

  • Even the slickest workarounds have problems. Try to fix or report settings-conversion bugs!!
  • Don't ever quit trying to fix a problem. Some day you'll have the solution and you will realize it was simpler than you thought.
  • realpath is your friend.
  • MonoDevelop (master branch) is now less buggy and as amazing as (or more than) ever (</PUBLIC_SERVICE_ANNOUNCEMENT>).
the avatar of Klaas Freitag

ownCloud Client 1.8.0 Released

Today, we’re happy to release the best ownCloud Desktop Client ever to our community and users! It is ownCloud Client 1.8.0 and it will push syncing with ownCloud to a new level of performance, stability and convenience.

[caption id=“attachment_586” align=“alignleft” width=“300”]The Share Dialog The Share Dialog[/caption]This release brings a new integration into the operating system file manager. With 1.8.0, there is a new context menu that opens a dialog to allow the user to create a public link on a synced file. This link can be forwarded to other users who get access to the file via ownCloud.

Also the clients behavior when syncing files that are opened by other applications on Windows has greatly been improved. The problems with file locking some users saw for example with MS office apps were fixed.

Another area of improvements is again performance. With latest ownCloud servers, the client uses even more parallized requests, now for all kind of operations. Depending on the synced data structure, this can make a huge difference.

All the other changes, improvements and bug-fixes are too hard to count. Finally, this release received around 700 git commits compared to the previous release.

All this is only possible with the powerful and awesome community of ownClouders. We received a lot of very good contributions through the GitHub tracker, which helped us to nail down a lot of issues and improved the client tremendously.

But this time we’d like to specifically point out the code contributions of Alfie “Azelphur” Day and Roeland Jago Douma who contributed significant code bits to the sharing dialog on the client and also some server code.

A great thanks goes out to all of you who helped with this release. It was a great experience again and it is big fun working with you!

We hope you enjoy 1.8.0! Get it from https://owncloud.org/install/#desktop

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FITRIM/discard with qemu/kvm for thin provisioning

My notebook computer is running with an SSD, and usually I'm creating logical volumes for the KVM VM's I install on it for testing purposes. On my normal file systems, I regularly run "fstrim" manually, to help the SSD firmware figure out which blocks can be reused. However, the LV's of the virtual machines usually stayed un-TRIM'ed. I had heard, that KVM/QEMU now supports the discard commands, but had not yet gotten to testing it.
I finally got to figuring out how it works:

First, you need to switch the VM to using virtio-scsi instead of virtio-blk:

Before:
<disk type='block' device='disk'>
  <driver name='qemu' type='raw'/>
  <source dev='/dev/main/factory'/>
  <target dev='vda' bus='virtio'/>
  <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/
</disk>
After:
<disk type='block' device='disk'>
  <driver name='qemu' type='raw'/>
  <source dev='/dev/main/factory'/>
  <target dev='sda' bus='scsi'/>
  <address type='drive' controller='0' bus='0' target='0' unit='0'/>
</disk>
<controller type='scsi' index='0' model='virtio-scsi'/>
Note the added scsi controller, and the only things you need to change are "target" and "address", if your source is different, that's ok.
Now check that your VM still boots. If it does not, then it is missing the virtio-scsi driver in the initrd. Reboot with the old configuration and build an initrd that includes all drivers, or at least the virtio-scsi driver. Another possible problem is the change from "/dev/vda1" to "/dev/sda1", check your fstab and use UUID or filesystem label for booting. Both problems did not occur to me on a stock Factory install (it uses UUID by default and had all drivers in initrd), but a hand-built kernel (built with "make localmodconfig"...) failed to boot, so be prepared.

Now you are using virtio-scsi for your device, but fstrim will still give you a "operation not supported" message. You'll need another parameter in your VM's configuration:
<driver name='qemu' type='raw' discard='unmap'/>
Restart the VM, and...
factory-vm:~ # fstrim -v /
/: 8,7 GiB (9374568448 bytes) trimmed
factory-vm:~ # 
Now what about thin-provisioning?
I converted the same VM from LV to a plain raw file.
This is the file on the host, it is sparse:
susi:/local/libvirt-images # ls -lh factory.raw
-rw-r----- 1 qemu qemu 20G Mar 15 14:05 factory.raw
susi:/local/libvirt-images # du -sh factory.raw
12G     factory.raw
Now let's delete some stuff inside the VM and run fstrim:
factory-vm:~ # du -sh /home/seife/linux-2.6/
3.9G    /home/seife/linux-2.6/
factory-vm:~ # rm -rf /home/seife/linux-2.6/
factory-vm:~ # fstrim -v /
/: 12.7 GiB (13579157504 bytes) trimmed
Checking again on the host:
susi:/local/libvirt-images # ls -lh factory.raw
-rw-r----- 1 qemu qemu 20G Mar 15 14:08 factory.raw
susi:/local/libvirt-images # du -sh factory.raw
6.4G    factory.raw
So this is really neat, as you now can free up space on the host after cleaning up in the VM. Maybe I should reconsider my "put all VMs into logical volumes" strategy again, as this wastes quite some valuable SSD space in my case.