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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Fedora 9 -> Fedora 10 online upgrade

February 11th, 2009 ntavares Posted in fedora, pt_PT 1 Comment »

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Aproveitando a onda da novidade (pois há pouco tempo instalei o Fedora 9), fiz online upgrade do Fedora e pela primeira vez também fiz upgrade do Fedora, de todo. Foi muito bom verificar o bom estado das coisas no momento, nomeadamente do mecanismo de upgrade da Fedora. Como não podia deixar de ser, estive a ler essa página, e resolvi testar a vertente "you can also TRY another method"/"this is not the recommended way", nomeadamente o PreUpgrade,  e de facto fiquei surpreso ...Muito bom mesmo! Read the rest of this entry »

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JXplorer in Fedora 9

July 7th, 2008 ntavares Posted in en_US, fedora, ldap No Comments »

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I just found this great tool for browsing LDAPs: JXplorer. After installing it, I had to tweak some stuff. It already had a hack, which was not working as expected, so you might have to install it this way:

export linux_LD_ASSUME_KERNEL_hack=1

After have it installed:

vi bin/JXplorer/JXplorer_LDAP_Browser

and chage (simple diff  style):

<     LD_ASSUME_KERNEL=2.2.5
>     #LD_ASSUME_KERNEL=2.2.5
>     LD_ASSUME_KERNEL=2.6.25

That should work.

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Fedora 9 review

July 7th, 2008 ntavares Posted in en_US, fedora 2 Comments »

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First of all, my apologies to the portuguese readers. This post is being written in english in an attempt to gather more audience, since it will contain resolutions to problems I've found. Also, forgive the delay, since it comes quite outdated (I've installed it 3 or 4 weeks ago).

I've recently upgraded my laptop HP/Compaq nx7400 (which was running a super-suprisingly-stable Fedora Core 6) to Fedora 9 due to my fear of getting discontinued¹. Since I used many hints from a post (lost the link), I thought of thanking to the community for it by writing this post.

The overall opinion is that FC9 is a compilation of some interesting new features, either in GNOME, kernel, or general utilities. However, FC9 didn't come out ready for the usual end-user. I maybe thrilling with it, but that's because I can solve things, usually the hard way. The usual end-user doesn't have time, nor patience, nor knowledge to fix this kind of this. As you will notice in this post, simple things still have complicated resolutions and, strangely, some already simple resolutions to simple things did just disappeared. But let's get over it!

While I was expecting having such feeling with everything else but this, my first feeling was a quite surprised "AT LAST"! There is no need to use ndiswrapper anymore to have my wireless  Broadcom Corporation BCM94311MCG (14e4:4311) working. Driver b43 now works out of the box, with the starter kernel; I noticed however that kernel had something broken as it stopped working. I'm now running (ed: and it's working as well.

For getting GoogleEarth to work smoothly, I had to struggle a bit. It was hogging with 3D. Check here for some hints, which worked.

What I think it's worth mentioning is the new kernel option i915.modeset=1. I still didn't have the time to explore it deeply. See here.

For Macromedia Flash to work, you will need to do a "yum install libflashsupport", or you won't get sound in the flash-plugin.

Regarding the office/pim suite, I maintained Thunderbird+Lightning. The problem was that Lightning got visually scrambled if you install it manually and I never understood why. After *hours* after it, I found that the RPM package thunderbird-lightning had to be installed, according to FedoraForum. It was so simple...

A funny utility I started to use some weeks ago is blueproximity. There was not an RPM ready for it, so I've built one (I prefer to always install by RPM, if possible). Check my homepage to get it.

Once in production, I need to install some True Type fonts. Just while I was thinking «uff! That was so much simplified in Fedora Core 6, it was just a matter of drag&drop them to a virtual folder font:///», I realized that gnome-vfs just disappeared and, as such, you just don't have a virtual fonts folder. Yup, it's true, they were not bluffing (when they said it would be discontinued). You won't have ssh:// and ftp:// and whatever:// support in nautilus as you used to. You now have a fuse-based approach, indeed, but I couldn't find any simple way to install new fonts - something that, as I mentioned, was already pretty usable. I managed to install the fonts copying them to ~/.fonts and checking the checkbox in fontmatrix (after installing it). So, this raises the question: if I need fontmatrix to install new fonts, why not make it part of the standard installation?

Another thing: if I'm supposed to use the gnome-keyring (since I have the option to store passwords), why the heck doesn't it install gnome-keyring-manager by default so I can manage my keys? OK, it's just a 'yum install' matter, but it forces the user to know the package name...

Another thing worth mentioning is the cool NetworkManager, which is becoming quite intelligent. It seems to be able to manage wired connections better (along with system-config-network),  as well as detect pluggable serial modems, like the GSM Huawei E220 HSDPA. Perhaps it's due to that better integration with system-config-network, my GSM connection is working via NetworkManager pretty well.

Regarding VMware Server, I fetched VMware 1.0.6-91891. Another cool thing is that I didn't need vmware-any-any anymore. But I did need to "yum install perl-ExtUtils-Embed" to get vmware-cmd to work. I now have a strange problem: whenever I go fullscreen in my Virtual Machines, the keyboard goes nuts - basically, I loose my case shifting powers. Struggling with it had to be postponed, which means I'll eventually fix it, but not for now.

So far, the updates have been released on a too-much-for-me rate, which seems good for the project. Unfortunately, that doesn't mean the packages are coming more stable...

== Notes ==

¹ Actually, this will probably be my last Fedora installation for a while. Not that there are better solutions out there, but because I'd like to have the same long experience with other distributions. And - I have to say it - I really dislike having to distupgrade every 6 months. It's a bit paradoxal, I know.

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