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How to convert OGG Vorbis .ogg to MP3 on GNU / Linux and FreeBSD

Friday, July 27th, 2012

I’ve used K3B just recently to RIP an Audio CD with music to MP3. K3b has done a great job ripping the tracks, the only problem was By default k3b RIPs songs in OGG Vorbis (.ogg) and not mp3. I personally prefer OGG Vorbis as it is a free freedom respecting audio format, however the problem was the .ogg-s cannot be read on many of the audio players and it could be a problem reading the RIPped oggs on Windows. I’ve done the RIP not for myself but for a Belarusian gfriend of mine and she is completely computer illiterate and if I pass her the songs in .OGG, there is no chance she succed in listening the oggs. I’ve seen later k3b has an option to choose to convert directly to MP3 Using linux mp3 lame library this however is time consuming and I have to wait another 10 minutes or so for the songs to be ripped to shorten the time I decided to directly convert the existing .ogg files to .mp3 on my (Debian Linux). There are probably many ways to convert .ogg to mp3 on linux and likely many GUI frontends (like SoundConverter) to use in graphic env.

SoundConverter Debian GNU Linux graphic GUI environment program for convertion of ogg to mp3 and mp3 to ogg, convert multiple sound formats on GNU / Linux.

I however am a console freak so I preferred doing it from terminal. I’ve done quick research on the net and figured out the good old ffmpeg is capable of converting .oggs to .mp3s. To convert all mp3s just ripped in the separate directory I had to run ffmpeg in a tiny bash loop.

A short bash shell script 1 liner combined with ffmpeg does it, e.g.;

for f in *.ogg; do ffmpeg -i "$f" "`basename "$f" .ogg`.mp3"; done.....

The loop example is in bash so in order to make the code work on FreeBSD it is necessery it is run in a bash shell and not in BSDs so common csh or tcsh.

Well, that’s all oggs are in mp3; Hip-hip Hooray 😉

Tags: audio cd, Auto, basename, bash shell script, BSDs, chance, code, consuming, csh, debian linux, Draft, ffmpeg, format, freak, freebsd, freedom, frontends, GNU, gnu linux, job, k3b, Linux, necessery, Ogg, ogg files, oggs, option, RIPs, script, Shell, soundconverter, terminal, time, time consuming, vorbis ogg, work
Posted in Everyday Life, FreeBSD, Linux and FreeBSD Desktop, Linux Audio & Video | No Comments »

How to disable PC Speaker on FreeBSD / Mute PC-Speaker on BSD kernels

Wednesday, May 16th, 2012

old school personal computer pc speaker / freebsd disable Pc-Speaker picture

After finding out How PC Speaker is muted on Linux , I've decided to also disable the annoying beeps on BSD. This is in tandem with the minimalistic philosophy I try to apply to every server I manage.

Also on BSD Desktop machines it is quite annoying especially if csh (C Shell) is used, everytime you press TAB you get the beep sound. On BSD beep sound produced on tab completion is louder than in Linux and that makes it even more annoying …

Disabling pc-speaker beeps on BSDs is done via a sysctl kernel variable:

freebsd# sysctl hw.syscons.bell=0 hw.syscons.bell: 0 -> 0

To further permanently disable on system boot add hw.syscons.bell=0 to /etc/sysctl.conf, e.g.:

freebsd# echo 'hw.syscons.bell=0' >> /etc/sysctl.conf

Well that's it no more mind drilling beeps :)

Tags: annoying beeps, Auto, beep, beep sound, bell, boot, BSD, BSDs, c shell, completion, conf, csh, Desktop, desktop machines, Disabling, Draft, drilling, everytime, freebsd, hw, kernel, kernels, Linux, mind, Mute, nbsp, pc speaker, philosophy, server, Sound, sysctl, system, system boot, tab, tab completion, tandem
Posted in FreeBSD, System Administration | No Comments »

Tools for finding files containing a string (recursively) in Graphical Enviroments (GNOME, KDE and XFCE) on GNU linux and FreeBSD

Monday, April 9th, 2012

1. Finding files containing a specific string with GNOME GUI tool gnome-search-tool

Default installation of GNOME version 2.x and 3.x is equipped with a tool called gnome-search-tool. The tool is used by default in the GNOME's file explorer program Nautilus. The quickest way to look for a certain text string across all the files located in a directory and show them is with nautilus's – find manager.

Below is a screenshot showing the gnome-search-tool embedded in nautilus

Nautilus find uses gnome-search-tool program for its file search. Below is a screenshot showing the gnome-search-tool embedded in nautilus:

The gnome-search-tool can be also invoked through Gnome Run Application with ALT+F2 or directly run from terminal e.g.:

hipo@noah:~$ gnome-search-tool

As you can see in below screenshot, gnome-search-tool has many available filter file search criterias.

You see I wanted to look for my project passwords so typed in pass in Contains the text: field and pressed enter to simply look for this text in all my files in the look in folder RichtooRich

Actually gnome-search-tool offers plenty of more options than one might look for. With it one can easily make a combination of complex search critea (filters) and hence a very versatile Desktop file saerch tool. From testing it I can say it for sure more powerful program than MS Windows default file searching program called Find It – this is the program with the ( "dumb dog holing a magnifier" 🙂

One can use the Add or Remove to Add single or various combination of filter criterias. For the sake of testing it, I've added a number of file search filters as you see in the shot below:

The search critias are not matched and therefore 0 files were found.
In case if you wonder how gnome-search-tool works? It is actually a GUI wrapper to Linux's Linux find command .

I wasn't complete sure if it uses find for the file search, so to check I run a one search and in in console ran:

hipo@noah:~$ ps axuwf|grep -i find
hipo 18213 2.0 0.0 25568 1276 ? S 23:55 0:00 find /home/hipo/Richtoorich ( -iname * -o -iname .* ) ! -type p -exec grep -i -I -c test {} ; -mtime -1 ( -size 102400 -o -size +102400 ) -user root ! -iname *bad\-name\-to\-omit* -print

You can see the filters set in gnome-search-tool are passed as command arguments to find.

2. Finding files containing a string recursively in KDE with kfind

For KDE users there is a handy little tool called Kfind. Kfind is less "search customizable" if it is compared to gnome-search-tool but it has advantage that its search options are way more "user friendly" / human readable 🙂

To use the tool to look in all files for explicit string fill in Look in: or browse to set the main directory where it will look for the string.

Then in the second Contents (tab) fill in the Containing Text: with the string to be looked for:

Finally in the Names/Location tab, there are two other helpful search options – Show Hidden Files and Case Sensitive Search

I'll be curious to hear if someone knows some other nice software easy and comprehensive to use for Linux / BSD. If you know a better file searcher for Linux than this kfind or gnome-search-tool please drop a comment.

Tags: default installation, explorer program, f2, file search, freebsd, gnome version, gnu linux, gui tool, hipo, kde, Linux, ms windows, nautilus, noah, recursively, screenshot, search criterias, search filters, search tool, text string, tool program, XFCE
Posted in FreeBSD, Linux and FreeBSD Desktop | No Comments »

How to delete million of files on busy Linux servers (Work out Argument list too long)

Tuesday, March 20th, 2012

How to Delete million or many thousands of files in the same directory on GNU / Linux and FreeBSD

If you try to delete more than 131072 of files on Linux with rm -f *, where the files are all stored in the same directory, you will get an error:

/bin/rm: Argument list too long.

I've earlier blogged on deleting multiple files on Linux and FreeBSD and this is not my first time facing this error.
Anyways, as time passed, I've found few other new ways to delete large multitudes of files from a server.

In this article, I will explain shortly few approaches to delete few million of obsolete files to clean some space on your server.
Here are 3 methods to use to clean your tons of junk files.

1. Using Linux find command to wipe out millions of files

a.) Finding and deleting files using find's -exec switch:

# find . -type f -exec rm -fv {} \;

This method works fine but it has 1 downside, file deletion is too slow as for each found file external rm command is invoked.

For half a million of files or more, using this method will take "long". However from a server hard disk stressing point of view it is not so bad as, the files deletion is not putting too much strain on the server hard disk.
b.) Finding and deleting big number of files with find's -delete argument:

Luckily, there is a better way to delete the files, by using find's command embedded -delete argument:

# find . -type f -print -delete

c.) Deleting and printing out deleted files with find's -print arg

If you would like to output on your terminal, what files find is deleting in "real time" add -print:

# find . -type f -print -delete

To prevent your server hard disk from being stressed and hence save your self from server normal operation "outages", it is good to combine find command with ionice, e.g.:

# ionice -c 3 find . -type f -print -delete

Just note, that ionice cannot guarantee find's opeartions will not affect severely hard disk i/o requests. On heavily busy servers with high amounts of disk i/o writes still applying the ionice will not prevent the server from being hanged! Be sure to always keep an eye on the server, while deleting the files nomatter with or without ionice. if throughout find execution, the server gets lagged in serving its ordinary client requests or whatever, stop the execution of the cmd immediately by killing it from another ssh session or tty (if physically on the server).

2. Using a simple bash loop with rm command to delete "tons" of files

An alternative way is to use a bash loop, to print each of the files in the directory and issue /bin/rm on each of the loop elements (files) like so:

for i in *; do rm -f $i; done

If you'd like to print what you will be deleting add an echo to the loop:

# for i in $(echo *); do \ echo "Deleting : $i"; rm -f $i; \

The bash loop, worked like a charm in my case so I really warmly recommend this method, whenever you need to delete more than 500 000+ files in a directory.

3. Deleting multiple files with perl

Deleting multiple files with perl is not a bad idea at all.
Here is a perl one liner, to delete all files contained within a directory:

# perl -e 'for(<*>){((stat)[9]<(unlink))}'

If you prefer to use more human readable perl script to delete a multitide of files use delete_multple_files_in_dir_perl.pl

Using perl interpreter to delete thousand of files is quick, really, really quick.
I did not benchmark it on the server, how quick exactly is it, but I guess the delete rate should be similar to find command. Its possible even in some cases the perl loop is quicker …

4. Using PHP script to delete a multiple files

Using a short php script to delete files file by file in a loop similar to above bash script is another option.
To do deletion with PHP, use this little PHP script:

<?php $dir = "/path/to/dir/with/files"; $dh = opendir( $dir); $i = 0; while (($file = readdir($dh)) !== false) { $file = "$dir/$file"; if (is_file( $file)) { unlink( $file); if (!(++$i % 1000)) { echo "$i files removed\n"; } } } ?>

As you see the script reads the $dir defined directory and loops through it, opening file by file and doing a delete for each of its loop elements.
You should already know PHP is slow, so this method is only useful if you have to delete many thousands of files on a shared hosting server with no (ssh) shell access.

This php script is taken from Steve Kamerman's blog . I would like also to express my big gratitude to Steve for writting such a wonderful post. His post actually become inspiration for this article to become reality.

You can also download the php delete million of files script sample here

To use it rename delete_millioon_of_files_in_a_dir.php.txt to delete_millioon_of_files_in_a_dir.php and run it through a browser .

Note that you might need to run it multiple times, cause many shared hosting servers are configured to exit a php script which keeps running for too long.
Alternatively the script can be run through shell with PHP cli:

php -l delete_millioon_of_files_in_a_dir.php.txt.

5. So What is the "best" way to delete million of files on Linux?

In order to find out which method is quicker in terms of execution time I did a home brew benchmarking on my thinkpad notebook.

a) Creating 509072 of sample files.

Again, I used bash loop to create many thousands of files in order to benchmark.
I didn't wanted to put this load on a productive server and hence I used my own notebook to conduct the benchmarks. As my notebook is not a server the benchmarks might be partially incorrect, however I believe still .they're pretty good indicator on which deletion method would be better.

hipo@noah:~$ mkdir /tmp/test hipo@noah:~$ cd /tmp/test; hiponoah:/tmp/test$ for i in $(seq 1 509072); do echo aaaa >> $i.txt; done

I had to wait few minutes until I have at hand 509072 of files created. Each of the files as you can read is containing the sample "aaaa" string.

b) Calculating the number of files in the directory

Once the command was completed to make sure all the 509072 were existing, I used a find + wc cmd to calculate the directory contained number of files:

hipo@noah:/tmp/test$ find . -maxdepth 1 -type f |wc -l 509072
real 0m1.886s user 0m0.440s sys 0m1.332s

Its intesrsting, using an ls command to calculate the files is less efficient than using find:

hipo@noah:/tmp/test$ time ls -1 |wc -l 509072
real 0m3.355s user 0m2.696s sys 0m0.528s

c) benchmarking the different file deleting methods with time

– Testing delete speed of find

hipo@noah:/tmp/test$ time find . -maxdepth 1 -type f -delete real 15m40.853s user 0m0.908s sys 0m22.357s

You see, using find to delete the files is not either too slow nor light quick.

– How fast is perl loop in multitude file deletion ?

hipo@noah:/tmp/test$ time perl -e 'for(<*>){((stat)[9]<(unlink))}'real 6m24.669suser 0m2.980ssys 0m22.673s

Deleting my sample 509072 took 6 mins and 24 secs. This is about 3 times faster than find! GO-GO perl 🙂
As you can see from the results, perl is a great and time saving, way to delete 500 000 files.

– The approximate speed deletion rate of of for + rm bash loop

hipo@noah:/tmp/test$ time for i in *; do rm -f $i; done
real 206m15.081s user 2m38.954s sys 195m38.182s

You see the execution took 195m en 38 secs = 3 HOURS and 43 MINUTES!!!! This is extremely slow ! But works like a charm as the running of deletion didn't impacted my normal laptop browsing. While the script was running I was mostly browsing through few not so heavy (non flash) websites and doing some other stuff in gnome-terminal) 🙂

As you can imagine running a bash loop is a bit CPU intensive, but puts less stress on the hard disk read/write operations. Therefore its clear using it is always a good practice when deletion of many files on a dedi servers is required.

b) my production server file deleting experience

On a production server I only tested two of all the listed methods to delete my files. The production server, where I tested is running Debian GNU / Linux Squeeze 6.0.3. There I had a task to delete few million of files.
The tested methods tried on the server were:

– The find . type -f -delete method.

– for i in *; do rm -f $i; done

The results from using find -delete method was quite sad, as the server almost hanged under the heavy hard disk load the command produced.

With the for script all went smoothly. The files were deleted for a long long time (like few hours), but while it was running, the server continued with no interruptions..

While the bash loop was running, the server load avarage kept at steady 4
Taking my experience in mind, If you're running a production, server and you're still wondering which delete method to use to wipe some multitude of files, I would recommend you go the bash for loop + /bin/rm way. Yes, it is extremely slow, expect it run for some half an hour or so but puts not too much extra load on the server..

Using the PHP script will probably be slow and inefficient, if compared to both find and the a bash loop.. I didn't give it a try yet, but suppose it will be either equal in time or at least few times slower than bash.

If you have tried the php script and you have some observations, please drop some comment to tell me how it performs.

To sum it up;

Even though there are "hacks" to clean up some messy parsing directory full of few million of junk files, having such a directory should never exist on the first place.

Frankly, keeping millions of files within the same directory is very stupid idea.
Doing so will have a severe negative impact on a directory listing performance of your filesystem in the long term.

If you know better (more efficient) ways to delete a multitude of files in a dir please share in comments.

Tags: Auto, client, deletec, deleteJust, Deleting, deleting files, Disk, downside, Draft, exec rm, eye, file, file deletion, freebsd, half a million, hard disk, heavy load, hipo, junk files, Linux, linux servers, maxdepth, multiple files, multitudes, multple, nbsp, new ways, noah, nomatter, number, obsolete files, operation, option, point of view, printing, quot, real time, rm command, servers work, Shell, ssh, terminal, test, time, tmp, type, unlink
Posted in Linux, Programming, System Administration | 12 Comments »

How to take area screenshots in GNOME – Take quick area selection screenshots in G* / Linux and BSD

Thursday, March 15th, 2012

Quick Area screenshot in GNOME how to make quick area selection screenshots in Linux and FreeBSD gnome-screenshot shot

Often when, you do something on your PC, you need to make a quick screenshot of a screen area.. Yes GNOME's feature to take complete screenshots of Screen with Print Screen SysRQ and consequential picture edit with GIMP is one way, but this is far away from quick. This method to chop out of a complete display screenshot usually takes from 40 secs to 1 minute to properly cut and save a selection of the whole picture.
Another common use, that I love in GNOME is the ALT + Print Screen SysRQ key combination. alt+ print scr sysrq is handy while taking a single window screenshot is desired. Anyways often you only need to make a screenshot of a tiny area of the screen. Many people might think this is not possible currently in GNOME, but they will be wrong as there are no impossible but hard things to achieve on Linux / FreeBSD 😉

There are at least two ways using a predefined command for taking quick area screen snapshot.

1. Taking quick area screenshot by using ImageMagick's import command

To use import you will need to have installed ImageMagick – swiss army knife of command line image manipulation 😉
For area screenshot with import, press ALT+F2 and type inside Run Application box:

Screenshot GNOME run application GNU / Linux Debian ImageMagick import area screenshot

import -frame screenshot.png

Now make the selection of the exact screen area you would like to screeshot in file screenshot.png
Note that screenshot.png file will be saved by default in your home directory as it is read from $HOME shell variable:

hipo@noah:~$ echo $HOME/home/hipo hipo@noah:~$ ls -al screenshot.png -rw-r--r-- 1 hipo hipo 4950 Mar 14 21:11 screenshot.png

You see my $HOME equals /home/hipo, therefore screenshot.png just grabbed is saved in there.

One downside of taking the screenshot with import is that picture snapshot is not further edittable, if it has to be further processed with GIMP or some other graphic editor program.

In the screenshot, below I show you one screen area of my XMMS taken with import -frame screenshot.png cmd:

XMMS Screen Area Screenshot import screenshot

Trying to open the screenshot.png, file with GIMP displays the following error in GIMP:

PNG image message PNG the file specifies offset that caused the layer to be positioned outiside image GIMP screenshot

Not all area snapshots taken with import -frame, create this issue sometimes screenshots are opening in GIMP but only area of the screenshot.png is visible in gimp.

Thanksfull, there is work around to this issue by converting the import generated PNG format picture to JPEG with ImageMagick's convert and then edit the .JPEG with GIMP etc.:

hipo@noah:~$ convert screenshot.png screenshot.jpg

Hence to permanently work around it, in case you intend to apply (GIMP modifications), once area snapshot is made instruct import to save its output picture in .jpeg, e.g.:

hipo@noah:~$ import -frame screenshot.jpeg

2. Taking quick area screenshot using gnome-screenshot cmd

Once again invoke the GNOME command Launcher by pressing Alt+F2 (holding alt and pressing F2) and type in the launch box:

gnome-screenshot -a

gnome-screenshot Run Application in GNOME 2.30 on Debian GNU / Linux

Below is a small area from my desktop, chopped with gnome-screenshot 🙂

GNOME desktop area chop screenshot with gnome-screenshot on my home Debian Linux

You see on above screenshot a tiny (picture) icon one of the greatest, if not the greatest bulgarian saint – saint John of Rila. St. John's lived as hermit for many years in Rila mountain and by God's grace possessed incorruptable body. His incorruptable body is still kept and can be venerated in Rila Monastery. The monastery is located 160 km from Bulgaria's capital city Sofia

St. Johns first Bulgarian established monastery Rila Monastery is currently the biggest functioing monastery in Bulgaria. The saints monastery is considered one of the most holy places in Bulgaria. If you have a travel or plan a holiday in Bulgaria, I warmly recommend you go there and venerate the saint incorruptable relics.

3. Binding keys to allow quick area screenshot taking with gnome-screenshot in GNOME

This configuration is for GNOME 2.x and is tested to work on my Debian (Squeeze 6.0), GNOME ver. 2.30.2, it should work in earlier Ubuntu versions shipped with GNOME 2.2.xx too. As I've red on the Internet it works well with Ubuntu 10.10Binding a key for screenshot area grab, should be working properly also on any GNOME 2.2.x supporting OS, including the BSD family OSes (FreeBSD, OpenBSD, NetBSD)…

a) setting gnome-screenshot key binding for interactive screenshot area grab

Navigate the mouse cursor to GNOME main menus panel in left top, where you see (Applications, Places, System).
Therein use menus:

System -> Preferences -> Keybord Shortcuts -> Add ->

Alternatively if you prefer you can directly invoke the Keyboard Shortcuts configuration with command:

hipo@noah:~$ gnome-keybinding-properties

Further on, assign a shortcut by filling in something like:

name: grab-screen-area command: gnome-screenshot -i -a

GNOME add keyboard shortcut map key for area interactive screenshot

press Apply and next map a key to the new defined key binding:

GNOME add keyboard shortcut map key

Under the Shortcut column click on Disabled and assign some key combination to invoke the cmd for example Ctrl+F4

The command gnome-screenshot -i makes gnome-screenshot, show interactive make screenshot dialog like the one in below screenshot.

GNOME screenshot interactive screenshot select area grab shot

b) creating gnome-screenshot -a area screenshot key binding for quick area screenshots "on the fly"

The procedure is precisely the same as with adding interactive screenshot; Under Keyboard Shortcuts GNOME config assign new key binding by pressing Add button and adding:

name: grab-screen-area1 command: gnome-screenshot -a

Once again in Shortcut column in line starting with grab-screen-area1 add your desired key switch. I personally like Ctrl+Print Screen SysRQ as it is close to the default GNOME key combination assigned for taking screenshot for a Windows Alt+Print SysRq

It was logical, that this key binding should work and a direct selection mouse cursor to appear once Alt+Print SysRQ is pressed, however for some reason this is not working (hmm, maybe due to bug) ??

Thanksfully it is always possible to substitute the just assigned gnome-screenshot -a key binding with import -frame /home/hipo/Desktop/screenshot.png

If you have followed literally my article so far and you did tried to place a bind for gnome-screenshot -a, modifty grab-screen-area1 to be something like:

name: grab-screen-area1 command: import -frame /home/hipo/Desktop/screenshot.png

Where modify the path /home/hipo/Desktop/screenshot.png, to wherever you prefer the region screep capture to be stored.

c) bind keys for delayed screenshot

This also a handy binding, especially if you every now and then need to make screenshots of screen with a few secs interval.
Add one more keyboard shortcut;

name: grab-screen-area2 command: gnome-screenshot -d 5

Assign a key to make a screenshot of the active display after a delay of 5 seconds. I prefer Ctrl+F5

Onwards every time you would like to make an area screenshot, just use the defined keys:

Ctrl+F4 - will prompt you interactively for the precise type of screenshot you would like to take Ctrl+Print SysRQ - will prompt you for a direct area to select and once selected will immediately screenshot it Ctrl+F5 - would do delayed screenshot of entire screen after a delay of 5 seconds

4. Adding border and drop shadow effects with gnome-screenshot Actually, there is plenty of interesting things to do with Screenshots which I never thought were possible.
While reading gnome-screenshot's man page, I've stumbled to an interesting argument:

-e, --effect=EFFECT, Add an effect to the outside of the screenshot border. EFFECT can be ``shadow'' (adding drop shadow), ``border'' (adding rectangular space around the screenshot) or ``none'' (no effect). Default is ``none''.

This would have been a nice feature but as of time of writting this article, untofrtunately it is not working in GNOME 2.30.2. I'm not sure if this is a local Debian bug, however I suspect on other Linux distributions with different GNOME build configuration, this features might be working well. My guess here is drop shadow effect and border effect are not working because, gnome-screenshot was compiled without (support for ImageMagick?).
Anyways the way the feature is supposed to be work is by invoking commands:
:

hipo@noah:~$ gnome-screenshot --border-effect=shadow hipo@noah:~$ nome-screenshot --border-effect=border

The same basic effects, are also available through GIMP's menus:

Image -> Effects

5. Setting default behaviour of gnome-screenshot in gconf-editor GConf (Gnome config registry db)

Experienced, GNOME users should already know about the existence of gconf-editor and the gnome registry database. For those who have don't, coming from MS-Windows background gconf-editor is GNOME (graphical environment) equivalent to Microsoft Windows registry regedit command

gconf-editor can be used to atune the way the screenshots are taken by default. To do so, launch gconf-editor cmd and follow to sub-structure:

/ -> apps -> gnome-screenshot

gconf-editor GNOME screenshot border effect none default gnome-screenshot gnome behaviour

The settings in above screenshot are configurations which are used by default by gnome-screenshot, right after install.
You can play with the options to change the default way PrintScreen SysRQ key press will take screenshots.
Here is one example for changing the gnome-screenshot default GNOME behaviour:

GConf Editor GNOME screenshot, border effect drop shadow and include border option set on Linux Debian

As you can see in above screenshot, I've changed my default gnome-screenshot snap taking to include a drop shadow effect:
Name | Value border_effect | shadow include_border | (tick on) last_save_directory | file://home/hipo/Desktop

As you see you can also control, where by default gnome-screenshot will save its screenshots, by default, its saved in $HOME/Desktop
. If you prefer some custom directory to only contain Screenshots taken for instance $HOME/Screenshots, create the directory:
hipo@noah:~$ mkdir ~/Screenshots

and then change the value for last_save_directory gconf var:

last_save_directory | file://home/hipo/Screenshots

Once settings are applied screenshots with Print Screen SysRQ key will be made with Shadow Border effect and saved in /home/hipo/Screenshots

Strangely enough, changing gnome-screenshot default screenshotting values to include screenshot effects like drop shadow or screenshot border effect works just fine.
Even though gnome-screenshot –border-effect=shadow and gnome-screenshot –border-effect=border doesn't directly affect the current screenshot to be made, I've later noticed writting this two commands in the gnome-terminal, does change the border settings for gconf-editor screenshot border.

If you enjoyed, this article and you intend to become "a professional screnshotter" :), you might also enjoy my two other articles:

Happy screenshotting 😉

Tags: Alt, area, Auto, Binding, body, border, BSD, command, consequential, cursor, Desktop, Display, downside, Draft, drop, exact screen, f2, feature, freebsd, GIMP, Gnome, graphic editor, home shell, image manipulation, import, import command, JPEG, key, line image, Linux, minute, noah, none, png file, Print, quot, Rila, scr, screen, screen snapshot, screenshot, secs, selection, shadow, shell variable, snapshot, something, swiss army knife, sysrq, time, tiny area, two ways, type, Ubuntu, use, way
Posted in Linux, Linux and FreeBSD Desktop, System Administration, Various | No Comments »

FreeBSD Jumbo Frames network configuration short how to

Wednesday, March 14th, 2012

Recently I wrote a post on how to enable Jumbo Frames on GNU / Linux , therefore I thought it will be useful to write how Jumbo Frames network boost can be achieved on FreeBSD too.

I will skip the details of what is Jumbo Frames, as in the previous article I have thoroughfully explained. Just in short to remind you what is Jumbo Frames and why you might need it? – it is a way to increase network MTU transfer frames from the MTU 1500 to MTU of 9000 bytes

It is interesting to mention that according to specifications, the maximum Jumbo Frames MTU possible for assignment are of MTU=16128
Just like on Linux to be able to take advantage of the bigger Jumbo Frames increase in network thoroughput, you need to have a gigabyt NIC card/s on the router / server.

1. Increasing MTU to 9000 to enable Jumbo Frames "manually"

Just like on Linux, the network tool to use is ifconfig. For those who don't know ifconfig on Linux is part of the net-tools package and rewritten from scratch especially for GNU / Linux OS, whether BSD's ifconfig is based on source code taken from 4.2BSD UNIX

As you know, network interface naming on FreeBSD is different, as there is no strict naming like on Linux (eth0, eth1, eth2), rather the interfaces are named after the name of the NIC card vendor for instance (Intel(R) PRO/1000 NIC is em0), RealTek is rl0 etc.

To set Jumbro Frames Maximum Transmission Units of 9000 on FreeBSD host with a Realtek and Intel gigabyt ethernet cards use: freebsd# /sbin/ifconfig em0 192.168.1.2 mtu 9000 freebsd# /sbin/ifconfig rl0 192.168.2.2 mtu 9000

!! Be very cautious here, as if you're connected to the system remotely over ssh you might loose connection to it because of broken routing.

To prevent routing loss problems, if you're executing the above two commands remotely, you better run them in GNU screen session:

freebsd# screen freebsd# /sbin/ifconfig em0 192.168.1.2 mtu 9000; /sbin/ifconfig rl0 192.168.1.2 mtu 9000; \ /etc/rc.d/netif restart; /etc/rc.d/routed restart

2. Check MTU settings are set to 9000

If everything is fine the commands will return empty output, to check further the MTU is properly set to 9000 issue:

freebsd# /sbin/ifconfig -a|grep -i em0em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 9000freebsd# /sbin/ifconfig -a|grep -i rl0 rl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 9000

3. Reset routing for default gateway

If you have some kind of routing assigned for em0 and rl0, network interfaces they will be affected by the MTU change and the routing will be gone. To reset the routing to the previously properly assigned routing, you have to restart the BSD init script taking care for assigning routing on system boot time:

freebsd# /etc/rc.d/routing restart default 192.168.1.1 done add net default: gateway 192.168.1.1 Additional routing options: IP gateway=YES.

4. Change MTU settings for NIC card with route command

There is also a way to assign higher MTU without "breaking" the working routing, e.g. avoiding network downtime with bsd route command:

freebsd# grep -i defaultrouter /etc/rc.conf defaultrouter="192.168.1.1" freebsd# /sbin/route change 192.168.1.1 -mtu 9000 change host 192.168.1.1

5. Finding the new MTU NIC settings on the FreeBSD host

freebsd# /sbin/route -n get 192.168.1.1 route to: 192.168.1.1 destination: 192.168.1.1 interface: em0 flags: <UP,HOST,DONE,LLINFO,WASCLONED> recvpipe sendpipe ssthresh rtt,msec rttvar hopcount mtu expire 0 0 0 0 0 0 9000 1009

6. Set Jumbo Frames to load automatically on system load

To make the increased MTU to 9000 for Jumbo Frames support permanent on a FreeBSD system the /etc/rc.conf file is used:

The variable for em0 and rl0 NICs are ifconfig_em0 and ifconfig_rl0.
The lines to place in /etc/rc.conf should be similar to:

ifconfig_em0="inet 192.168.1.1 netmask 255.255.255.0 media 1000baseTX mediaopt half-duplex mtu 9000" ifconfig_em0="inet 192.168.1.1 netmask 255.255.255.0 media 1000baseTX mediaopt half-duplex mtu 9000"

Change in the above lines the gateway address 192.168.1.1 and the netmask 255.255.255.0 to yours corresponding gw and netmask.
Also in the above example you see the half-duplex ifconfig option is set insetad of full-duplex in order to prevent some duplex mismatches. A full-duplex could be used instead, if you're completely sure on the other side of the host is configured to support full-duplex connections. Otherwise if you try to set full-duplex with other side set to half-duplex or auto-duplex a duplex mismatch will occur. If this happens insetad of taking the advantage of the Increase Jumbo Frames MTU the network connection could become slower than originally with standard ethernet MTU of 1500. One other bad side if you end up with duplex-mismatch could be a high number of loss packets and degraded thoroughout …

7. Setting Jumbo Frames for interfaces assigning dynamic IP via DHCP

If you need to assign an MTU of 9000 for a gigabyt network interfaces, which are receiving its TCP/IP network configuration over DHCP server.
First, tell em0 and rl0 network interfaces to dynamically assign IP addresses via DHCP proto by adding in /etc/rc.conf:

ifconfig_em0="DHCP" ifconfig_rl0="DHCP"

Secondly make two files /etc/start_if.em0 and /etc/start_if.rl0 and include in each file:

ifconfig em0 media 1000baseTX mediaopt full-duplex mtu 9000 ifconfig rl0 media 1000baseTX mediaopt full-duplex mtu 9000

Copy / paste in root console:

echo 'ifconfig em0 media 1000baseTX mediaopt full-duplex mtu 9000' >> /etc/start_if.em0 echo 'ifconfig rl0 media 1000baseTX mediaopt full-duplex mtu 9000' >> /etc/start_if.rl0

Finally, to load the new MTU for both interfaces, reload the IPs with the increased MTUs:

freebsd# /etc/rc.d/routing restart default 192.168.1.1 done add net default: gateway 192.168.1.1

8. Testing if Jumbo Frames is working correctly

To test if an MTU packs are transferred correctly through the network you can use ping or tcpdumpa.) Testing Jumbo Frames enabled packet transfers with tcpdump

freebsd# tcpdump -vvn | grep -i 'length 9000'

You should get output like:

16:40:07.432370 IP (tos 0x0, ttl 50, id 63903, offset 0, flags [DF], proto TCP (6), length 9000) 192.168.1.2.80 > 192.168.1.1.60213: . 85825:87285(1460) ack 668 win 14343 16:40:07.432588 IP (tos 0x0, ttl 50, id 63904, offset 0, flags [DF], proto TCP (6), length 9000) 192.168.1.2.80 > 192.168.1.1.60213: . 87285:88745(1460) ack 668 win 14343 16:40:07.433091 IP (tos 0x0, ttl 50, id 63905, offset 0, flags [DF], proto TCP (6), length 9000) 192.168.1.2.80 > 192.168.1.1.60213: . 23153:24613(1460) ack 668 win 14343 16:40:07.568388 IP (tos 0x0, ttl 50, id 63907, offset 0, flags [DF], proto TCP (6), length 9000) 192.168.1.2.80 > 192.168.1.1.60213: . 88745:90205(1460) ack 668 win 14343 16:40:07.568636 IP (tos 0x0, ttl 50, id 63908, offset 0, flags [DF], proto TCP (6), length 9000) 192.168.1.2.80 > 192.168.1.1.60213: . 90205:91665(1460) ack 668 win 14343 16:40:07.569012 IP (tos 0x0, ttl 50, id 63909, offset 0, flags [DF], proto TCP (6), length 9000) 192.168.1.2.80 > 192.168.1.1.60213: . 91665:93125(1460) ack 668 win 14343 16:40:07.569888 IP (tos 0x0, ttl 50, id 63910, offset 0, flags [DF], proto TCP (6), length 9000) 192.168.1.2.80 > 192.168.1.1.60213: . 93125:94585(1460) ack 668 win 14343

b.) Testing if Jumbo Frames are enabled with ping

– Testing Jumbo Frames with ping command on Linux

linux:~# ping 192.168.1.1 -M do -s 8972 PING 192.168.1.1 (192.168.1.1) 8972(9000) bytes of data. 9000 bytes from 192.168.1.1: icmp_req=1 ttl=52 time=43.7 ms 9000 bytes from 192.168.1.1: icmp_req=2 ttl=52 time=43.3 ms 9000 bytes from 192.168.1.1: icmp_req=3 ttl=52 time=43.5 ms 9000 bytes from 192.168.1.1: icmp_req=4 ttl=52 time=44.6 ms --- 192.168.0.1 ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 3003ms rtt min/avg/max/mdev = 2.397/2.841/4.066/0.708 ms

If you get insetad an an output like:

From 192.168.1.2 icmp_seq=1 Frag needed and DF set (mtu = 1500) From 192.168.1.2 icmp_seq=1 Frag needed and DF set (mtu = 1500) From 192.168.1.2 icmp_seq=1 Frag needed and DF set (mtu = 1500) From 192.168.1.2 icmp_seq=1 Frag needed and DF set (mtu = 1500)

--- 192.168.1.1 ping statistics --- 0 packets transmitted, 0 received, +4 errors

This means a packets with maximum MTU of 1500 could be transmitted and hence something is not okay with the Jumbo Frames config.
Another helpful command in debugging MTU and showing which host in a hop queue support jumbo frames is Linux's traceroute

To debug a path between host and target, you can use:

linux:~# traceroute --mtu www.google.com ...

If you want to test the Jumbo Frames configuration from a Windows host use ms-windows ping command like so:

C:\>ping 192.168.1.2 -f -l 8972 Pinging 192.168.1.2 with 8972 bytes of data: Reply from 192.168.1.2: bytes=8972 time=2ms TTL=255 Reply from 192.168.1.2: bytes=8972 time=2ms TTL=255 Reply from 192.168.1.2: bytes=8972 time=2ms TTL=255 Reply from 192.168.1.2: bytes=8972 time=2ms TTL=255 Ping statistics for 192.168.1.2: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 2ms, Maximum = 2ms, Average = 2ms

Here -l 8972 value is actually equal to 9000. 8972 = 9000 – 20 (20 byte IP header) – 8 (ICMP header)

Tags: article, Auto, baseTX, boost, BSD, card, card vendor, change, code, Configuration, connection, Draft, eth, ethernet cards, Frames, freebsd, gateway, gigabyt, GNU, gnu screen, host, Jumbo, jumbo frames, Linux, linux os, maximum transmission, mediaopt, MTU, Netmask, network, network configuration, network interface, network tool, nic card, package, post, quot, Realtek, router server, scratch, screen, screen session, source code, ssh, tool, transmission units, way
Posted in FreeBSD, System Administration | 1 Comment »

One more day passed

Thursday, November 29th, 2007

One more day passed. I have pains and I scream to God for guidance and help. I’m not sure where am going to as usual. Today we had to have German. I wentto the college only to find out that the German lesson is removed from the schedule. A friend of mine who is in germany Shaltev has sent me a Video of his band.The band is called viamala, here is there website http://viamala.org. I really liked there music btw. Tomorrow I have Dutch. The day was a sort of quite for me thanks and Praise be to the Lord creator. By the way my health is not well. I have pains in different organs sometimes. You know life is hard. I’m loving more and more the FreeBSD :). I watched Ice Age and currently I’m watching Ice Age 2. Great anime (I’m having fun with it. I often think of becoming a monk. Life is such a vanity.END—–

Tags: age, anime, band, becoming a monk, college, creator, end, freebsd, german lesson, germany, god, guidance, having fun, health, Ice, lesson, life, lord creator, mine, monk, music, organs, Praise, sort, tomorrow, vanity, viamala, way
Posted in Everyday Life | No Comments »

The week

Tuesday, January 8th, 2008

After 10 minutes I’ll have Deutcsh lessons anyways I’ve caught some winter virus :)I’m having snots coughing and stuff. In Sunday I was on a Liturgy in the Church as usual.Yesterday was a quiet and peaceful day. Static came home and we installed Windows. NowI have Windows,Linux,FreeBSD on one machine. I’m surprised how well is Windows working.I’m eating a lot of garlic recently to stimulate my immune system. Yesterday I playedsome Warcraft III. Having Windows now gives me the opportunity to play some gameswhich weren’t working in wine. Well that’s most of how my day passed. I went to seemy grandma and she made me tea as always (her tea is awesome!). :)END—–

Tags: end, freebsd, gameswhich, garlic, grandma, home, immune system, Linux, liturgy, machine, NowI, opportunity, peaceful day, playedsome, seemy, Static, system, tea, virus, warcraft iii, weren, Windows, wine, yesterday
Posted in Everyday Life | No Comments »

Still Here

Wednesday, January 17th, 2007

Aloha. Still here. Two days ago I ran Heroes 3 under my FreeBSD box successfully, there was a terrible bug in fullscreen mode which needed fix I’ve used the loki’s site patch to patch the heroes 3 start binary with xdelta. The loki installer was a terrible pain in the ass I used my l337test sk!llZ :} to be able to patch the binary by hand. About the last post yes I was desperate still not good still living. Today I was on exam again a failure probably, nothing new.

As I often used to say in the fast if something starts bad then it overs bad too. See my life show this very well. I’m suffering terrible and still waiting for something to set me free to happen. What would be the turning point? Will there be turning point at all? No idea. If God is such good and powerful as he said in the bible and his promises are true then he will deliver me and set me free on a good ground. Still hoping … Prodigy — Speedway, else the earth is probably his favourite experiment.

Tags: bible, earth, experiment, failure, favourite, freebsd, fullscreen, god, ground, hand, heroes, idea, life, llZ, loki, Mode, pain, pain in the ass, post, Prodigy, promises, show, site, something, speedway, test, turning, turning point, xdelta
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Knowing Not! :]

Monday, January 22nd, 2007

Today I have Marketing exam. Ofcourse as usual when I have exams I haven’t studied enough, and again I’m in the situation realizing I don’t know anything. I depend 100% on God’s grace to take that exam. Why I’m so dumb never study when

I have what I have. I can’t change my self I can’t study something I’m not interested into. Marketing is a subject which is simple but for Jerks IMHO :]. The logic of marketing is too abstract.

And yes what’s happening with me the last days. Well I’m feeling good now Praise the Lord. I’ve no idea what I should do with my life. I have 2 re-exams for now or maybe 3 ( I don’t know the results from the Research & Statistics Exam ).

The last few days I ran FreeDOS and Windows 2000 Pro SP4 under FreeBSD 6.2 with qemu. FreeDOS’s performance is very nice despite the fact it is emulated. The Windows is running a little laggish although I ran it with kqemu ( Experimental Module for qemu which enhances the typical qemu speed ). Yesterday we drink a dark beer with Nomen into the “Happy Person” Pub. My passion for computers is starting to come back again.

Tags: amp, Beer, change, dark beer, experimental module, few days, freebsd, FreeDOS, god, Happy, idea, IMHO, Jerks, laggish, last days, ldquo, life, logic, marketing, Module, nomen, Ofcourse, passion, performance, Praise, Pub, qemu, rsquo, self, statistics, study, windows 2000, yesterday
Posted in Everyday Life | No Comments »

☩ Walking in Light with Christ – Faith, Computing, Diary

Posts Tagged ‘freebsd’

One more day passed

Still Here

Knowing Not! :]

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