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Linux after work

After a day of working with Nagios on Linux, I went home an reinstalled my laptop. I installed Linux of course. I installed Ubuntu 9.04 in stead of Debian.

Nagios is one of my favorite applications for Linux. The monitoring options are incredible. I want more people to monitor there environment with nagios.

 

Fedora 11 first impressions

Being impatient, as usual, I couldn't wait for the official release date, heh.

So far I've updated two of my Linux boxes (work and main home PC) using yum.  There were a few hiccups, but nothing I couldn't handle.  Mainly just some depsolving issues that required that I remove packages, and some signing problems that required I do "--nogpgcheck".  I don't recommend doing it this way unless you have a pretty in depth understanding of the packages on your system, what they are for, and yum and RPM in general.  If you care if you hoze your system, or don't feel confident that you can solve whatever problems come up, wait for the DVD release and upgrade that way.

After the updates were all done, /etc/sysconfig/redhat-release shows "Fedora release 11 (Leonidas)", and we're about a week out from the official release, so I figure not much will change before it officially goes to general release.  Here's a gratuitous uname -a as well ;)

"Linux cube64.int.hozed.net 2.6.29.3-140.fc11.x86_64 #1 SMP Tue May 12 10:44:27 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux"

The only disappointment is that the on-board audio on my home system's motherboard still doesn't work properly under PulseAudio.  Not a huge surprise, since it didn't work under 10.  I usually use a USB headset, so it's not a show stopper, but it is a bit annoying.  I really wish that the ALSA driver and Pulse would play nice.  The sound will "work" if I disable glitch free, but it sounds like crap.  I don't hold it against Fedora, because all distros that have switched over to Pulse seem to be having the same problems.  I'm still amazed that the audio subsystem seems to be the most trouble prone part of Linux on the desktop.  I can run DirectX games written for another operating system full screen at 1920x1200, do all sorts of advanced network magic, etc, but can't get sound to work right on a very common audio chipset (Intel HDA).  It just seems so counter-intuitive.  That said, when Pulse/ALSA play nice, it's awesome sauce.  Hopefully by F12 this will all be straightened out, but I'm not holding my breath.  I do think the various distros have jumped the gun a bit on making it THE audio subsystem, but I suppose it wouldn't really get widely tested otherwise. 

On a good note, when using my USB headset, as well as the onboard chipset on my office PC, sound works flawlessly.  Also, Pulse's CPU utilization has dropped to around 1% when playing sounds and under 1% when idle, which is an improvement.  (doesn't hurt that I've got a quad core Phenom II at 3ghz though, heh, so YMMV)

But, anyway, this isn't meant to be an audio rant. ;)

Over all, things look more polished.  I really like the changes to the update app.  The audio preferences overhaul looks nice too, however power users may find it a little overly simplistic.

On a side note, I just upgraded to a 28" widescreen LCD, and everything looks sexier at 1920x1200!

Boot and shutdown times are noticeably faster.  I was actually a little surprised the first time I rebooted.  If it hadn't been for the delay when the Nvidia video driver's init script kicks off, and the time spent acquiring a DHCP lease from my ISP, my boot time from GRUB to GDM would have been under 20 seconds. 

Over all, the system feels snappier, but that may just be my imagination.

Every piece of hardware was recognized perfectly from the first boot, and it "just works" with the exception of the audio stuff mentioned above.  The only third party driver I have installed is the Nvidia driver, but that's for the sake of gaming, not general use.  The video worked fine for normal desktop stuff on the open-source driver.

The virtual machine manager has a nice improvement in that you can assign USB or PCI devices to a virtual guest through the GUI now.  I've been looking forward to that feature.  There looks to be an easy GUI way to migrate hosts as well, though I don't have the setup to test that particular feature.

Over all, I'm very happy with my shiny new Fedora.  I'm looking forward to the MythDora 11 release for my mythbox, and I'll be upgrading my other PC and my laptop, as well as our virtualization server at work to F11 soon as well.

 

NOOB's adventures in Linux From Scratch

 Hello again,

   Today has been a wonderful day. I was looking for a kinda recipe for the command line. No one was able to help me. I would ask around chats and they'd say read the man pages. All fine and good if you know what you're looking at but man pages have always been very cryptic for me. Info pages seem a bit better but I need nuts and bolts and I guess I really couldn't get to the core of what I needed. Then a gentleman who overheard me on IRC complain about a user's guide.. pointed me to  http://rute.2038bug.com/index.html.gz ... At first I was a bit conserned I'd been had as this page was extracting :O But what soon followed was pure pleasure.

   Here , I'd found what I was looking for, ( I think ) I could read it. I didn't need a scientific dictionary , I didn't feel like a total fool . It's wonderfully written. The Author goes on to state that he would like you to have a Redhat "like" or debian "like" distribution installed so if he ask you can have available the program to use.

   then he put me right at ease by saying:

Any system reference will require you to read it at least three times before you get a reasonable picture of what to do. If you need to read it more than three times, then there is probably some other information that you really should be reading first. If you are reading a document only once, then you are being too impatient with yourself.

Next , I get a really big smile when I read :

The LPI and RHCE are two certifications that introduce you to LINUX. This book covers far more than both these two certifications in most places, but occasionally leaves out minor items as an exercise. It certainly covers in excess of what you need to know to pass both these certifications.

  Wow, not only do I feel like I'm learning alot and even understanding man pages now that before I started this book didn't have a clue , man pages overwhelmed me. I even am beginning to feel comfortable with the command line.

   I might even qualify for some certifications that weren't my primary objective.

   Right now I'm reading mostly man pages as an exercise , mostly from coreutils and reviewing many of the primary commands.

Think it's been 12 days or so since I decided to try and build LFS... right now it's not looking like it's going to be as long a journey as I once thought. 

 

Adventures of a noob: Gentoo (part1) - Know your grub!


Learnt with pain:

One of the most important things if not nearly the most important thing in installation of gentoo by a person not considering himself a guru in linux is configuring the bootloader. The reason is very simple. Migrating from other OS, you most probably would like to keep your stable working operating system for a little bit while messing with gentoo. The installation is sometimes long and quite painful process along which any simplest problem might prevent you from actual using gentoo for everyday operations. Example would be an issue with a graphics driver which would not allow you to properly configure xorg and therefore you would have to use console for a while. I don't know about you, but personally I can't use Links and alike to check my email. My eyeballs turn red, nose starts bleeding and all that bad stuff. And because checking e-mail is something so ridiculously important for a University student nowadays, I would need a working X. The workaround for this particular problem is just using LiveCD which has a guied browser. But the point is understood: you would want to keep another working OS unless you install gentoos everyday like crazy and can do it without a monitor! Hence, you should always have a properly configured boot loader.


Personal Experience:

Here I want to illustrate how bad it is to underestimate the importance of configured bootloader.

It was winter of 2008-2009, the winter break at college so I went home. I was an alltime Ubuntu user at the moment and (as mentioned in earlier posts) decided to try Gentoo. I got to the point (about that in the next post) where I had working gentoo with no Xorg and no network. The xorg part at that point was just the matter of learning how to configure it manually. For network - somebody should have told me about DHCP!!! Anyway, I basically couldn't do anything on it (when I said "working gentoo" I meant the kernel was actually loading :-D). The computer at home had Windows (for mama) and Ubuntu for myself. I erased ubuntu during the process of gentoo installation, but of course the grub was still there! And since it was configured long ago automatically by Ubuntu, ...nothing loaded. The only possibility for me was the LiveCD on which I pretty much lived for quite a bit. The most painful part was when my mom came over once and said "I need to check my email". It was very hard to explain a 40-year old piano teacher why the computer could only produce green text on the black screen and why in the hell that "was ok". I loaded the livecd but it turned out she had all the passwords saved on her windows. For a month I was claimed to have broken the family computer and somehow erasing all of the "collected for long time" by real careful users' passwords. I made her happy when I finally figured out GRUB and could eventually load her windows WITH ALL THE PASSWORDS ALREADY THERE!!! So much joy...


Advice from a noob:

Guys on Gentoo.org give a really nice description of GRUB and guidelines of how to work with it in the handbook. Pay attention to that, go to different sources if it doesn't make sense, look up the grub's config on your distro, but you have to know your grub!

 

My SPLAT

SPLAT

 
Guess what, I have SPLAT in my notebook, easy to install and easy to use. :)

 

Remote port tunnelling with SSH

Hi there, here's a quick blog about SSH port forwarding, let's describe the scenario with an example, of course port forwarding may be applied to everythin, not only to mysql as reported in the sample

 

Assume you've a remote host with MySQL server installed and running, of course for security reasons you've forbidden TCP connections from every machine except localhost, or at least this is how I usually configure my services. Your Python, PHP, Java apps and even CLI apps are happy with it, they can access mysql backend by connecting to localhost on 3306 port.

For security reasons when you're inside the mysql server you can connect to my by using:
myserver:~$ mysql --host=127.0.0.1 --user= --password=
pretty safe and good, I usually configure MySQL in this way:
myserver:~$ cat /etc/mysql/my.cnf|grep "bind-address"
bind-address = 127.0.0.1

so far, everything is perfect now but if you need to manage your remote db with MySQL Administrator or with your preferred tool how can you connect to this machine ? Easy, let's forward remote 3306 port to local 3306 or other port if needed, then you can connect to localhost and use the SSH tunnel in between. from your local machine:
localmachine:~$ ssh -l -L 3306:localhost:3306
So you open an ssh console to your machine from your localhost, with the connection you ask remote to port forward its 3306 port to your local 3306.
Now try to open your remote db from localhost, so if you use mysql command line utility you need to type:
localmachine:~$ mysql --host=127.0.0.1 --user= --password=
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 254
Server version: 5.0.51a-24 (Debian)

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql>

And that's it !

Obviously you can even use your favorite admin tool, not only mysql cli

 

Pretty easy and quick

Hope it helps someone

Ben

 

Remote desktop single command execution

On RDP protocol v5 and above you can open a remote windows session and open a single program only instead having the whole desktop up, it sounds like Metaframe but cheaper, I mostly use it from my Linux workstation for opening win programs on the server (business accounting apps or legacy win apps).
You need to have rdesktop installed in your system, each distro has its own names for this package

quick command from your linux desktop:

~$ rdesktop -u -p -d -g 1280x1024 -T "" -k it -s "notepad.exe" &

We're now opening notepad on remote machine and using it on local Linux desktop, I've just setup my resolution to 1280x1024 but of course you can change it to whatever you want

You'll have notepad opened on your desk ,when you close it rdesktop closes it by itself, this applies to windows servers with RDP 5 (example: win 2003 server or above)

 

Comments welcomed

Ben

 

Dual Boot Mac Mini

I was pleasantly surprised that changing a Mac Mini to dual boot Mac OS X and Linux was relatively painless. I more or less followed the instructions here: http://www.rickycampbell.com/ubuntu-easy-install/

I ran the Boot Camp thing in the Utilities folder and allocated the disk half and half.  (I was kind of annoyed that it assumed I was going to install Windows.)

Then I installed the rEFIt boot manager:  http://refit.sourceforge.net/

Finally, I installed Ubuntu 9.04.  The only problem now is that the display comes up in 800 x 600 when I boot into Linux.

 

 

Just„ÄÄstarted Local Drupal Group

Drupalのユーザーになってしまったのですが、残念なことに日本ではDrupalを使っている人が少ない。

I happen to be a Drupal user. But in Japan Drupal is not popular.

日本では商用ではMoovable Type,オープンソースではXoopsが人気のようですね。

In Japan, Moovable type and Xoops is popular.

でDrupalユーザーをネットで探したら、同じ思いをしている人がいてグループを立ち上げました。

And I was looking for a users on the net and found and decide d to have meet up events.

第一回の集まりでは18人のユーザーが、集まりました。

At the first meeting we have 18 users.

今週末は2回目の集まり。前回は時間が足りなかったので今回はちょっと多めになんと8時間。

This weekend is 2nd time gethering, and 8hours.

„Åß„ÇÇÊ•Ω„Åó„Åø„ÄÇ

 http://groups.drupal.org/node/22239

 

 

NEWB's adventures in Linux From Scratch

  Hello again,

   It seems I have the talent for sticking my foot in my mouth. I've just recently been informed that noob stands for : someone who believes they know it all , but in reality know little to nothing at all.  I stand corrected. (I though I said I was a newbie)

   Now that I've apparently found a book that I can understand,  learning is becoming much easier. I'm starting to organize.  Many of the things will save me time like the bash ctrl key functions so I've made a kind of overlay (remember Word Perfect?) that way I'll learn much faster. Seems that there are list and notes everywhere  in this book. There's a lot to learn and I've got to have somewhere easy to recall the most important things. For me that's a real paper notebook. 

 

FFMPEG Cropping and Re-sizing (order matters)

I discovered something whilst trying to crop and re-size a video with FFMPEG: the order of switches actually matters! I couldn't find any mention of this in the documentation, and nowhere could I find an explanation of why my video was being cropped after it was resized. The video I was re-encoding had some fuzziness at the top, and an ugly black border down the right-hand side. I wanted to remove these, but have a fixed output size.

Here's an example. Our input file, input.avi is a 640x480 video.

We run the following 2 commands:

ffmpeg -i input.avi -s qvga -croptop 8 -cropright 22 output1.avi
ffmpeg -i input.avi -croptop 8 -cropright 22 -s qvga output2.avi

Notice that in the first case, we've set the size first (qvga means 320x240).

In the second case we set the cropping first.

Now let's look at the output with: file *.avi.

input.avi: RIFF (little-endian) data, AVI, 640 x 480, 25.00 fps, video: XviD, audio: MPEG-1 Layer 3 (stereo, 44100 Hz)
output1.avi: RIFF (little-endian) data, AVI, 298 x 232, 25.00 fps, video: FFMpeg MPEG-4, audio: MPEG-1 Layer 1 or 2 (stereo, 44100 Hz)
output2.avi: RIFF (little-endian) data, AVI, 320 x 240, 25.00 fps, video: FFMpeg MPEG-4, audio: MPEG-1 Layer 1 or 2 (stereo, 44100 Hz)

As you can see, the first output file has its dimensions cropped after resizing. The second one before, and its the second one I wanted, cropping the video first, then resizing it.

I have never encountered a command-line app where the order of the switches actually mattered, until now. I don't know how many other ffmpeg switches this also applies to, but I thought I'd share it as I personally couldn't find anything about it elsewhere.

Hope this is helpful!

Thom

 
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