greygraph on CentOS

April 1st, 2012 ntavares Posted in centos, en_US, fedora, monitorização, performance | No Comments »

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Today I gave a look at greygraph, a mailgraph-based tool for displaying sqlgrey graphs.

Here are the adaptations to run it in CentOS. Have a look at the README inside the distribution, anyway, After unpacking the distribution tarball:

  1. mkdir -p /var/cache/greygraph
  2. chgrp apache /var/cache/greygraph/
  3. chmod g+w /var/cache/greygraph/

Review etc/default/greygraph and copy it to /etc/sysconfig/greygraph:

  1. mv etc/default/greygraph  /etc/sysconfig/greygraph

Place files and directories directories:

  1. mkdir -p /usr/share/greygraph
  2. mv usr/lib/cgi-bin/greygraph.cgi  /usr/share/greygraph/
  3. mv var/www/css/greygraph.css /usr/share/greygraph/
  4. mv usr/sbin/greygraph /usr/sbin
  5. mkdir -p /var/lib/greygraph

As for the SysV script, I've adapted mailgrah's. Download the script greygraph (remove .txt extension).

In the meantime, I'll try to add the generated RRDs to cacti [1, 2], let me know if you managed to do so.

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Watch out for kernel >= 3.0 power saving regressions…

November 30th, 2011 ntavares Posted in en_US, fedora, linux driver, performance, ubuntu | No Comments »

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I was reading Phoronix comprehensive tests about recent power saving regressions - specifically important for laptops -, and would like to point out this to everyone, since, according to the article, it is not receiving much attention from kernel maintainers. As you know, I recently installed a Sony Vaio and an HP G62. Just to give an idea of what I'm talking about, have a look at their chart:

Phoronix Tests on power saving regressions

Also worth mentioning are the Intel graphics tuning options. I'm currently running these on both computers (as both have an i915 card), and yet didn't find any problem...?

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Sony Vaio Z21X9E/B (CEP) and Fedora 15 (x86_64)

November 26th, 2011 ntavares Posted in dri, en_US, fedora, hardware, linux driver | No Comments »

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Well, I'm one of the recent owners of a Sony Vaio VPC Z21X9E - who the heck is giving these brand model names at Sony?? - so, as everyone does when they get a new computer, I went to install my operating system - Linux. And, despite having said that it would probably not be Fedora again, well..... it was. And, yes, I was still using a 2-year-old distribution...


It worths mentioning that this laptop does not have a CD-ROM drive, so you either plug in an external one, use an USB pen or just kickstart it.

You might want to pass the following options on installation if you're getting a blank screen:


If you want to preserve the Windows installation you will probably have to resize the "big" partition manually: I couldn't get anaconda, nor Ubuntu installer, nor SuSE's, so in the end, I gave up and went using the resizentfs tools.

Also, if you plan to wipe off the Windows partitions completely, you might want to try to tune the disk first by aligning the SSD. I didn't: I was hungry for having it installed, and I already spent much time trying to install Linux without blowing Windows (it may become handy to debug some USB... :-)



Ethernet (Wired)

Although the Ethernet NIC was correctly detected, the base kernel driver r8169 had some stability problems. My first yum update brought kernel with the problem fixed. But it worths mentioning that first I had installed the Realtek's official driver (donwload link) and it performed pretty well.

If you're dealing with recent kernels, you may have noticed about Consistent Network Device Naming. Well, in short, I don't like it :) So I told udev to get my 'eth0' back - can you imagine? It was called p3p1! :)

cat > /etc/udev/rules.d/80-compatibility-net.rules << EOF
# PCI device 0x10ec:0x8168 (r8169)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="54:42:49:97:75:22", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

This is a two line file (first line is a comment), but Wordpress breaks it.


Although the wireless card (Intel Corporation Centrino Advanced-N 6230) was detected, the driver iwlagn needs firmware (you'll notice that on 'dmesg'):

yum install iwl6000g2b-firmware.noarch

Broadband internal modem (Gobi 3000)

I'm still wandering around on a good approach to this one. Many many info scattered around the web, with different results, with different models. For now, let me just reference to the Gobi drivers project page. I'll get back on this as soon as I have something similar to an understandable approach.

Touchpad / Clickpad

You will quickly notice that the touchpad (actually, a Clickpad, I learned) will misbehave, leading to cursor jumps when you try to click, ignoring drag&drop, etc. It seems the synaptics driver is pending some clickpad awareness changes - for a long time now, I must say - and that's why you will find the problem solved in (and by) many (other) distributions. Not in Fedora, though, at least in this case. In Bugzilla #590835, comment35, thanks to Alexander Gryanko, you will find a source RPM for a workaround. After recompiling and installing over your current xorg-x11-drv-synaptics driver, the clickpad won't perform as well as in Windows, yet, but it will fix the annoying pointer-jump and will allow you to drag&drop and select text, which was impossible.

I've also read about using "i8042.nomux=1" as kernel arguments, or Sony Jogdial overlapping the default touchpad (noticeable on the logs) but didn't go that way. I'd like to hear from your experience about this, though.

Also, installing gpointing-device-settings might become handy later on...

yum install gpointing-device-settings

Keyboard Fn keys

They all seem to perform well, except for brightness control. I've seen many people complaining about this. Loading the sony_laptop module seems to do the trick.

modprobe sony_laptop


While you had to run the installation without modesetting, after the forementioned update (to kernel, the system now runs with modesetting, thus giving you the graphical boot.

Other hardware

  • Webcam - out of the box;
  • Audio - out of the box;


Frequently used applications

I found a lot of good suggestions here, although I always go installing the software along the way, as I need it. So this section is mainly targetting some special care needed for specific apps.


I like to (I actually have to) use both a legacy most stable version (1.6x) and a most updated stable version (1.7.x) due to professional reasons, so I like to have alternatives properly setup so I can switch between them easily. This is something that the Java RPM distribution should be doing automatically (for some years now), but they still don't:

alternatives --install /usr/bin/javaws javaws /usr/java/default/bin/javaws 10
alternatives --install /usr/bin/java java /usr/java/default/bin/java 10
alternatives --config java
rm /usr/java/default
ln -s /usr/java/jdk1.6.0_29 /usr/java/default

Tweaking the environment

Fallback mode (ignore gnome-shell)

I hated gnome-shell. I understand the distribution maintainers want to push new stuff into the audience, but I still feel most of the changes happened on Gnome 3 are pretty unfair for a desktop user. My computers are not a tablet, I can't point with the finger, so this gnome-shell thing (Unity in Ubuntu, and alike) is just garbage for me. I don't like them because they make me loose more time to find my things - which I had somehow inconsciently automated. So, obviously, I'm running in the "fallback mode", which you can set using the gnome-control-center, on a unobvious "System Info" icon.

Delete key behaviour

After that, I spent some time trying to get back to the old behaviour, like using the DELETE key for what it used to do: delete stuff. Through the following command, you'll be able to mouseover menu options and set the accelerator (shortcut) by pressing DELETE twice on the option "Move to Trash". Learn more here.

gsettings set org.gnome.desktop.interface can-change-accels true

Desktop area management and icons

I believe this has been forgotten about the fallback mode: we used to have icons and be able to create folders and other nautilus operations, so I want that.... again. You can use dconf-editor to edit the configuration visually or using gsettings, again:

yum install dconf-editor
gsettings set org.gnome.desktop.background show-desktop-icons true

Adding menu entries

Maybe it's just a fallback miss, but it won't originally let you modify the Applications menu. For that, you'll have to install alacarte and run it from console (or ALT+F2):

yum install alacarte

The entries created with alacarte (0.13.2-3) will miss the category no matter if you specify it on item creation. To place the icons where they're due, you'll have to edit the shortcuts, which are placed at ~/.local/share/applications. Just add an entry Categories=Development (example) and wait a couple of seconds so the panel freshens up. If you're wondering about which categories to place, grep through /usr/share/applications/*.desktop for examples.


I was reading some of the powertop suggestions and doing some reading in the meanting, so these seemed to be worth considering:

Disable NMI Watchdog (ref):

echo 0 > /proc/sys/kernel/nmi_watchdog

Set wwan0 down if you're not going to use it

ifconfig wwan0 down &

Disable Wake-up On LAN:

ethtool -s eth0 wol d &

Enable laptop mode, I don't know if it's still relevant nowadays (ref):

echo 5 > /proc/sys/vm/laptop_mode

Some interesting stuff I read on LessWatts:
Scheduler tunables for multi-socket systems (ref

echo 1 > /sys/devices/system/cpu/sched_mc_power_savings
echo 1 > /sys/devices/system/cpu/sched_smt_power_savings

Set vm writeback to 10 secs (lose 10 secs on crash):

echo 1500 > /proc/sys/vm/dirty_writeback_centisecs

Disable bluetooth entirey

hciconfig hci0 down

Disable wireless - if you'r not going to use it... maybe this could be integrated with the physical switch of the Vaio...

ifconfig wlan0 down
modprobe -r iwlagn

Enable Audio HD powersave

echo 10 > /sys/module/snd_hda_intel/parameters/power_save &

I will hardly make any kind of power consumption comparison between Windows and Linux - I won't be in Windows that long :-) - but, anyway, it makes sense to not leak power on unused components.

That's all for now.

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Talend in Fedora 15

August 26th, 2011 ntavares Posted in en_US, fedora, talend | 1 Comment »

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Add this to TalendOpenStudio-linux-gtk-x86.ini


You can check that /usr/lib/xulrunner-2 is indeed the correct path by listing files provided by xulrunner package.

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10º Aniversário da Wikipédia Lusófona

May 11th, 2011 ntavares Posted in lazer, pt_PT, web, wikipedia | No Comments »

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Já saíram os resultados do 8º WikiConcurso, realizado a propósito do 10º Aniversário da Wikipédia lusófona!

O Oitavo WikiConcurso foi um concurso organizado pelos Wikipedistas para promover a qualidade dos artigos considerados essenciais na Wikipédia e, pela primeira vez, serão atribuídos prémios reais, palpáveis, pela Wikimedia Portugal e pelo grupo Wikimedia Brasil. A data do Concurso foi alinhada para coincidir também com o décimo aniversário da Wikipédia Portuguesa, tendo sido por isso decidido pela Wikimedia Portugal oferecer aos concorrentes prémios de participação (T-shirts, pins e autocolantes que faziam parte do kit oferecido pela WMF para a comemoração do 10º aniversário da Wikipédia) e 3 flash drives com o software WikiTwooGO para os primeiro classificados.

O objectivo do concurso foi, nesta edição do WikiConcurso, melhorar a qualidade dos artigos considerados essenciais para qualquer enciclopédia, e que são usados como comparação entre as Wikipédias de várias línguas e entre a Wikipédia e várias enciclopédias tradicionais. Além disso, pretendeu ser uma forma de mostrar apreço pelas contribuições dos voluntários promovendo uma competição amigável entre os editores mais produtivos da Wikipédia, festejando os 10 anos da Wikipédia com melhorias ao próprio conteúdo da enciclopédia.

Em termos de iniciativa por parte da Wikimedia Portugal, a iniciativa encontra-se descrita na página de projecto respectiva, e decorreu sobre a orientação do colega Gonçalo Themudo, a quem deixo os parabéns pelo resultado.

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Wiki Loves Monuments… e há imensos!

May 2nd, 2011 ntavares Posted in pt_PT, web, wikipedia | No Comments »

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Em 2011 a edição do Wiki Loves Monuments (WLM) sai da esfera Neerlandesa (ou Holandesa, como diria a maior parte das pessoas). O ano passado, praticamente metade dos monumentos dos Países Baixos tiveram fotografias, e este ano as câmeras estão focadas nos monumentos de grande parte da Europa. O WLM já tem logótipo estabelecido — foi concebido por uma portuguesa (parabéns Lusitana!) — e a organização já decorre há algum tempo. Em Portugal, está a ser organizado pela Wikimedia Portugal (WMP), como é óbvio.

Setembro é o mês em que estará tudo a postos; podem ver o planeamento no Commons. Claro que podem já a começar a tirar fotos mas, para essas fotografias poderem concorrer, só poderão ser carregadas no Commons em Setembro. Se nunca utilizou o Commons, agora é uma boa altura para aprender. Se tem fotografias que nunca carregou para lado nenhum, Setembro será uma boa altura para submetê-las.... no Commons :-) Para esse efeito, será disponibilizado um formulário simplificado, para que seja ainda mais simples carregar múltiplas fotografias.

Os monumentos a fotografar não estarão apenas em países com Capítulos (associações equivalentes à WMP de outros países); por exemplo, se viajar para a Bélgica, que também participa, porque não levar uma câmera, e concorrer para os dois países. Para Portugal, a lista já está disponível e a ser compilada com toda a informação disponibilizada pelo IGESPAR e SIPA/IHRU.

Em Portugal, espera-se uma cerimónia de entrega de prémios, e uma nova oportunidade de conhecer e reencontrar Wikipedistas lusos.

Aqui fica um vídeo de apresentação para esta iniciativa:

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KnowledgeTree Workflow Import/Export Tool

April 30th, 2011 ntavares Posted in en_US, knowledgetree, projects | No Comments »

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This is an important feature that’s missing in KnowledgeTree, and must certainly agree with me if you work with different knowledgetree installations. This is particularly useful if you have different systems, like one for prototyping and validation and the live one. This plugin will allow you to export your Workflows in a number of formats. So far, these are supported: Graphviz data, Graphfiz image, JSON and Simple XML. As soon as there is particular interest in BPMN, I’m willing to support it as well, but it hasn’t been needed, yet.

Here are some screenshots. These are the new Administration pages available (same section from KTEmailPush Plugin):
New Administration pages

... from where you can Export...
Workflow Export Page

...and Import. This page highlights a collision detection situation, where the user is presented with the imported workflow process, and which how the plugin should handle the collision: merge, create another workflow (renamed) and do nothing.
Workflow Import Page

Special care will be taken in the future, as it's yet very simple, focusing only States and Transitions. This is a list of issues I will address:

  • Assigned and related permissions
  • Assigned and related users,groups and roles
  • Workflow Effects

It’s ready for 3.7.x and it will soon be available for download. Visit the Projects page for more information or drop me a note for demo/download information.

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KnowledgeTree jump/GotoCustomNumber Plugin

April 30th, 2011 ntavares Posted in dri, en_US, knowledgetree, projects | No Comments »

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If you’re using the Custom Numbering Plugin, which is available in the Professional version of KnowledgeTree, you might find useful to jump directly to the document by looking up the Custom Number of the document, pretty much like you do with the Goto Document ID dashlet, which uses the (internal and unmeaningful) document ID. A practical use of this plugin has been to use it with barcode scanners on physical archives.

It's ready for 3.7.x and it will soon be available for download. Visit the Projects page for more information.

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Mounting disk images with multiple partitions

February 1st, 2011 ntavares Posted in en_US, filesystems, hardware | No Comments »

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This is a common scenario: you made a disk image from a disk which wanted to wipe out, but when you finally arrange some time to do proper backup (you're probably not interested in backing up your /tmp, for instance), you don't even remeber what's on it.

First of all, you'll need to know the disk's partition layout:

  1. [root@machine backup_disks]# parted disco2
  2. GNU Parted 1.8.6
  3. Using /array/backup_disks/disco2
  4. Welcome to GNU Parted! Type 'help' to view a list of commands.
  5. (parted) unit                                                             
  6. Unit?  [compact]? B                                                       
  7. (parted) print                                                           
  8. Model:  (file)
  9. Disk /array/backup_disks/disco2: 80060424192B
  10. Sector size (logical/physical): 512B/512B
  11. Partition Table: msdos
  13. Number  Start       End           Size          Type     File system  Flags
  14.  1      32256B      106928639B    106896384B    primary  ext3         boot
  15.  2      106928640B  80056650239B  79949721600B  primary               lvm 
  17. (parted) quit

I prefer 'parted' as it handles partition tables on files better than fdisk, but I suppose you could use 'fdisk -l' as well (ignoring the warnings and errors).

The easiest way (although not the quickest) is to simple 'dd' from it, using seek/skip counters, according to the partition table.

The following is the quickest approach: you can just mount simple partitions, like "boot" in the above example with:

  1. [root@machine backup_disks]# mkdir mymount
  2. [root@machine backup_disks]# mount -o loop,seek=32256,ro disco2 mymount

But, in the case of LVM, you need to scan and join it to the LVM pool you probably already have (refer to the LVM howto, for more information). This is due to LVM not being a filesystem (which could be mounted) but rather a partition type, in this case. So, first of all, you'll want to "export" that partition as a block device, so it can be analyzed by the LVM tools. You can do that with the loopback tools:

  1. [root@machine backup_disks]# losetup -o 106928640 /dev/loop1 disco2

You should be able to access the raw partition at /dev/loop1 and, thus, it's now visible to 'pvscan':

  1. [root@machine backup_disks]# pvscan
  2.   PV /dev/loop1   VG VolGroup00   lvm2 [74,44 GB / 32,00 MB free]
  3.   PV /dev/md0     VG VolGroup00   lvm2 [3,18 TB / 64,00 MB free]

This is also another common situation, due to distribution defaults: you mounted a disk that shares the Volume Group name with the running disks. It's better to rename it ASAP, before confusion happens:

  1. [root@machine backup_disks]# vgdisplay
  2.   --- Volume group ---
  3.   VG Name               VolGroup00
  4.   System ID             
  5.   Format                lvm2
  6.   Metadata Areas        1
  7.   Metadata Sequence No  3
  8.   VG Access             read/write
  9.   VG Status             resizable
  10.   MAX LV                0
  11.   Cur LV                2
  12.   Open LV               1
  13.   Max PV                0
  14.   Cur PV                1
  15.   Act PV                1
  16.   VG Size               74,44 GB
  17.   PE Size               32,00 MB
  18.   Total PE              2382
  19.   Alloc PE / Size       2381 / 74,41 GB
  20.   Free  PE / Size       1 / 32,00 MB
  21.   VG UUID               4BAKDW-94eP-0ZjE-aa7n-Efab-gu0m-5NF0GX
  23.   --- Volume group ---
  24.   VG Name               VolGroup00
  25.   System ID             
  26.   Format                lvm2
  27.   Metadata Areas        1
  28.   Metadata Sequence No  2
  29.   VG Access             read/write
  30.   VG Status             resizable
  31.   MAX LV                0
  32.   Cur LV                1
  33.   Open LV               1
  34.   Max PV                0
  35.   Cur PV                1
  36.   Act PV                1
  37.   VG Size               3,18 TB
  38.   PE Size               64,00 MB
  39.   Total PE              52165
  40.   Alloc PE / Size       52164 / 3,18 TB
  41.   Free  PE / Size       1 / 64,00 MB
  42.   VG UUID               9xAyLn-5jex-Bc00-0zmG-CPA0-x9Sx-3M3eio

Check the ID of the new volume (in this case: 4BAKDW-94eP-0ZjE-aa7n-Efab-gu0m-5NF0GX) and use vgrename to do so:

  1. [root@machine backup_disks]# vgrename 4BAKDW-94eP-0ZjE-aa7n-Efab-gu0m-5NF0GX VolGroup00_oldmachine
  2.   Volume group "VolGroup00" successfully renamed to "VolGroup00_oldmachine"

Check everything went well, again with pvscan:

  1. [root@machine backup_disks]# pvscan
  2.   PV /dev/loop1   VG VolGroup00_oldmachine   lvm2 [74,44 GB / 32,00 MB free]
  3.   PV /dev/md0     VG VolGroup00           lvm2 [3,18 TB / 64,00 MB free]
  4.   Total: 2 [1,26 TB] / in use: 2 [1,26 TB] / in no VG: 0 [0   ]

There you go! Now you should be able to follow standard LVM approaches to mount the volume.

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10º Aniversário Wikipédia

January 11th, 2011 ntavares Posted in lazer, pt_PT, wikipedia | No Comments »

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Caros, mais do que explicar-vos do que se trata, vejam o outdoor que fizémos! Aproveito para deixar o link para o site do evento. Participem e ajudem a divulgar! Basta clicar na imagem, imprimir e afixar algures! :-)


Parabéns Wikipédia!

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