Therefore the blog was moved to wordpress.com - please wait until the change is propagated through DNSes.

I’m going to Desktop Summit

I am sorry for lack of the exact quotes or references but I was unable to find them. They were spread over several weeks and I found only paid archives so I am not able to pinpoint exact newspapers.

One of the articles spoke about Wikileaks and tried to compare the current situation to 1968 stating that the current internet is too one-contact-only to provide platform for revolution giving as an example a message from twitter which makes one time contact and that the revolution needs continuity.

I belive that there are 2 problems with such analysis. First of all I’m not quite sure how many contacts are one-time-only. Arguably one of the most popular site on the internet, Facebook, is based rather on the continous contacts rather then one time. Some studies indicates that the our core groups involve around 4-5 people. Setting aside the social networks any other communications involve known people – you relativly rarely send e-mail to stranger.

Secondly the internet is not homogenious. According to wikipedia This was the first generation to grow up with television in their homes. (…) Chain stores and franchised restaurants were bringing shared shopping and dining experiences to people in different parts of the world. These factors all combined to create a generation that was more self-aware and more united as a group than the generations before it. – in other words it was the beginning of the mass market. However the internet seems to be somehow the end of mass market in some sense as it allows the comeback of the niches.

While it may not unify the revolution it provides platforms for revolution as it connects similar-minded people. You can find communities of the conservatives, socialists, libertatian, anarchists of all kinds etc. For some ideologies it is primary platform of propagation. Recent events in Egypt and Algieria had shown that it is useful tool in this role.

I don’t want to imply that revolution will actually happen. The article was more interesting as what people think about the internet from outside then the revolution itself.

PS I have writted main part of article on 14 of January. Therefore it speak about wikileaks as “recent events”. I decided eventually to post it now – especially in context of the events in Egypt and Algerial world. I don’t want to discuss what actually happened there and what are the consequences – the important part from this post POV is that internet proved to be useful as a platform.

I don’t use the recommended by developers method of building for two reasons. First of all I have rather limited amount of disk space, especially on ‘/home’, and the duplication of many libraries and include files (I use Gentoo) seems to not be an option for me. Secondly installing in Jhbuild sandbox prevents from seeing overall impact of changes in Gnome on system (like some packages, including Firefox, failing to build some time ago with new gtk+ 2).

As a result it more often does not work then do. Excluding some ‘obvious’ reasons like crashes it now requires new gnome-settings-daemon which requires libnotify 0.7, which changes abi and api breaking everything that uses libnotify on my system (mostly from Gnome so hopefully most are fixed but not only). Libnotify is not parallel installable so I can either move to JHbuild or resign from using gnome-shell.

For gnome-shell language, JavaScript, was chosen as easily embeddable and widely known. In addition it doesn’t pull in another complicated platform (and it allows to avoid “duplication” with glibraries). The problem pointed by others. I guess that most JavaScript use are through libraries like JQuery. Anyway the problem isn’t the language itself – when I tried to write simple plugin some time ago I found very little resources to get a hello-world example working. While mokey patching may provide certain benefits crashing shell when one tries to find out how to add something to GUI is not preferable. Additionally it seems that there are problems with embedding javascript anyway.

Release late, release never. The gnome-shell seems to have some features present on screenshots and videos (including ones from GUADEC) that I could never found in one I get from git/tarballs – like multiple views in overview mode. On the other hand it constantly relies on git including sometimes releases of gnome-shell depending on gjs from git. Finding working configuration seems to be hard – while possibly it is made easier by JHbuild I don’t want to use it for reasons above.

Last point is ongoing discussion about the gnome-shell hardware requirements. Contrary to gnome-panel and metacity gnome-shell requires 3D acceleration and while I’m “lucky” (I have new integrated intel card – not great for gaming but works on Linux) some reported issue on NVidia. Even on intel card sometimes it seems that the system slows down during heavy loads (although it improved in 2.6.36 kernel).

Finally I’d like to remaind that the post is written from my own perspective and I may have biased view (including different method of installing and not being involved into design process). In some parts I exagareted (“Release late, release never”) for only reason of joking – and I hope noone will feel offended because of it. However I have my concerns about Gnome-Shell and Gnome 3.0 which, I hope, are invalid.

Hopefully everything will work out-of-the-box, although I have my doubts about the rss/atom – I hope they will work/be updated. I also expects that DNS change have fully propagate by now.

I hope that my blog will be updated more often however I cannot promise anything. So far I have 2 drafts of posts.

However about two years ago (to be exact 02 October 2008 I wanted to change the email address. I receive following reply:

Maciej Marcin Piechotka wrote:
> Is it possible to update the email to xxx@xxx.xxx.xx?

For the account of which of the many users we have?

Greets,
 XXXXXX

When I sent e-mail containing my handle (assuming they are asking for it) I receive no reply.

Similar conversation tok place in May 2010. The third was on 09 August 2010 (however I receive no reply):

Please update my e-mail. This one may no longer be valid after september
2010[1].

Username: XXXX-SIXXS
Current e-mail: xxx@xxx.xxx.xx
New e-mail: xxx@xxx.xxx.xx [2]

[1] I requested e-mail update some time ago but there has been no
response so far
[2] It is valid as far as I understand according to new domain policy
despite bing hosted on xxxx. If it is not please use
xxx@xxx.xxx.xx

I tried to submit a ticket (the FAQ stated that the proper channels are either via e-mail or ticket system and the e-mail obviously failed) in which I described the whole situation stating that my e-mail might get blacklisted by accident. On following day I found out it was deleted.

Still thinking there are some technical problems I asked forum for advice what should I do. The post was deleted within minutes – they apparently don’t have the time to change e-mail over 2 years but do have time to closely monitor the forum they stated they don’t closely monitor. The account have been disabled shortly afterwards.

I haven’t found anything in FAQ that I have broken with possible exception of not signing at bottom of the e-mail by my full name. Message was signed by GPG key, from account that do not bounce (check several times) etc. I haven’t also receive response why my account was disabled. In meantime I moved to Tunnel Broker.

Traditional solution was to forward-declarate it:

class A;

class B
{
public:
  B(A *) {}
};

class A
{
  static B b;

};

However it have its limitations. For example B cannot call A methods making such solutions useless. Other solution is spliting functions and class declaration – however it may cause problems if they will not match (for example some functions remain undefined):

class A;

class A
{
  static B b;
public:
  void doIt();
};

class B
{
public:
  B(A *);
  void doSomething();
};

void A::doIt()
{
  b.doSomething();
}

B::B(A *a)
{
  if(a != NULL)
    a->doit();
}

void B::doSomething()
{

}

There is solution, at least working on gcc 4.4. Let’s define B as a template:

template
class B
{
public:
  B(A *a)
  {
    if(a != NULL)
      a->doit();
  }
  void doSomething() {}
};

class A
{
  static B b;
public:
  void doit()
  {
    b.doSomething();
  }
};

Probably we consider writing each time <![CDATA[B]]> waste of space. We can simply forward-declare class and set the default arguments:

class A;

template
class B
{
public:
  B(A *a)
  {
    if(a != NULL)
      a->doit();
  }
  void doSomething() {}
};

class A
{
  static B b;
public:
  void doit()
  {
    b.doSomething();
  }
};

However I thought I do not need it. Well – what are my needs? 10 GiB for /usr for sure is enough, /var etc. on separate partitions with appropriate size. Rest for /home. As many times before live proved me wrong. Recently I started running of the space on /usr – and have plenty of space on /home – which was not only not-optimal but started stopping my system from working.

Please note that in following text I use the term LVM meaning LVM 2. I also take no responsibility for any action resulted from reading this blog.

System with LVM

It will take a long time to move all of those partitions I thought. However I remaind myself about LVM. Why not try it?

To create a system with LVM you need a few things. Firstly you need a kernel module. If you want your / partition in LVM you need it either compiled-in or put into initrd. As we will not communicate directly with module we need userspace tools. Thirdly we need some disk space.

Let’s assume /dev/sda5 is a partition you have created. pvcreate /dev/sda5 changes it into a Physical Volume. PV is a name of a "partition" on which real data is stored (it need to be stored eventually somewhere). However the advantage of LVM is that PV is only Physical Volume – not the Logical.

Next step is to create a Volume Group. Volume Group, as the name implies, groups the volume – both physical and logical. Running vgcreate vg /dev/sda5 creates VG with name vg and the PV /dev/sda5. If you want you may create VG on more PV simply by supplying more arguments. If you’d like to add /dev/sda6 in the future vgextend vg /dev/sda6 is your friend. It is worth to point out that VG is not limited to one disk only and therefore can work in similar fashion to RAID 0.

The final step is to create a Logical Volume. LV is similar to partition is sense that you create a filesystem on it. However it does not have to be continous or even on a single disk. HoweverLVM takes care low-level details. As the LV have no specific order you can name it (please note that the label of partition is something different) – for example usr. lvcreate -L12G -nusr vg creates 12 GB logical volume named usr using VG vg.

Now you can easily format the hard drive with your favourite FS. For example ext4 – mkfs.ext4 /dev/vg/usr.

Why to do it?

Assume that the 12GB is insufficient for /usr – you need to extend it by 2 GB. Ok – what to do? Simply lvextend -L+2G /dev/vg/usr will resize the volume – you don’t have to unmount the FS. In most GNU/Linux FS, such as reiserfs, jfs, xfs or ext2/3/4, it can be done on-line without unmounting the filesystem. In the LVM HOWTO it is stated that the ext2/3/4 online resizing requires additional patch – however no such information is stated in ext4 wiki.

For more informations please read LVM HOWTO

When I first run Paludis it welcomed me with a bunch of warnings. While QA is perfect for developers it is not perfect for the user. Some of the problems were problems of my configuration and some were gentoo bugs. However some seemd to be overcaution of paludis.

Other problem is that the Paludis checks carefully the dependency tree when I run paludis -i world it reads and checks the whole tree. While I admit that it can help avoid some unwanted situation it causes paludis to run about 3 times slower than emerge.

Usually during the update I want to revise it firstly. Emerge offers nice option --ask which first shows what it is going to install and then asks if I want to install it. However there is no such option in paludis. May be it can be added by hooks.

On the other hand it has advantages as well. It is much stricker then portage so it helps with developing ebuilds. It is, despite the initial long running time, quite fast, especially compared to portage and it can be much easier extended.