Posts Tagged ‘zxvvf’

Fix vnstat error “eth0: Not enough data available yet.” on Debian GNU / Linux

Monday, November 21st, 2011

Vnstat GNU Linux console terminal traffic statistics logo

After installing vnstat to keep an eye on server IN and OUT traffic on a Debian Squeeze server. I used the usual:

debian:~# vnstat -u -i eth0

In order to generate the initial database for the ethernet interface used by vnstat to generate its statistics.

However even though /var/lib/vnstat/eth0 got generated with above command statistics were not further generated and trying to check them with command:

debian:~# vnstat --days

Returned the error message:

eth0: Not enough data available yet.

To solve the eth0: Not enough data available yet. message I tried completely removing vnstat package by purging the package e.g.:

debian:~# apt-get --yes remove vnstat
...
debian:~# dpkg --purge vnstat
...

Even though dpkg –purge was invoked /var/lib/vnstat/ refused to be removed since it contained vnstat’s db file eth0

Therefore I deleted by hand before installing again vnstat:

debian:~# rm -rf /var/lib/vnstat/

Tried installing once again vnstat “from scratch”:

debian:~# apt-get install vnstat
...

After that I tried regenerating the vnstat db file eth0 once again with vnstat -u -i eth0 , hoping this should fix the error but it was no go and after that the error:

debian:~# vnstat --hours
eth0: Not enough data available yet.

persisted.

I checked in Debian bugs mailing lists and I found, some people complaining about the same issue with some suggsetions on how the error can be work arouned, anyways none of the suggestions worked for me.

Being irritated I further removed / purged once again vnstat and decided to give it a try by installing vnstat from source
As of time of writting this article, the latest stable vnstat version is 1.11 .
Therefore to install vnstat from source I issued:

debian:~# cd /usr/local/src
debian:/usr/local/src# wget http://humdi.net/vnstat/vnstat-1.11.tar.gz
...
debian:/usr/local/src# tar -zxvvf vnstat-1.11.tar.gz
debian:/usr/local/src# cd vnstat-1.11
debian:/usr/local/src/vnstat-1.11# make & make all & make install
debian:/usr/local/src/vnstat-1.11# cp examples/vnstat.cron /etc/cron.d/vnstat
debian:/usr/local/src/vnstat-1.11# vnstat -u -i eth0
Error: Unable to read database "/var/lib/vnstat/eth0".
Info: -> A new database has been created.

As a last step I put on root crontab to execute:

debian:~# crontab -u root -e

*/5 * * * * /usr/bin/vnstat -u >/dev/null 2>&1

This line updated vnstat db eth0 database, every 5 minutes. After the manual source install vnstat works, just fine 😉

How to install and configure djbdns from source as a Cachening Localhost Proxy resolver to increase resolving efficiency on Debian 6 Squeeze

Monday, August 1st, 2011

djbdns-logo-install-configure-djbdns-from-source-on-gnu-linux-to-accelerate-server-dns-resolving
It seems DjbDNS on Debian Squeeze has been not included as a Debian package. There is still possibility to install djbdns from an older deb package or install it from source. I however decided to install it from source as finding the old Debian package for Lenny and Etch takes time, plus I'm running an amd64 version of Debian and this might even more complicate the situation.
Installing it from source is not really a Debian way but at least it works.

In this article I assume that daemontools and ucspi-tcp are preliminary installed, if not one needs to install them with:

debian:~# apt-get install ucspi-tcp daemontools daemontools-run
...

The above two ones are required as DJBDNS is originally made to run through djb's daemontools.

Here is the exact step I took to have it installed as local caching DNS server on a Debian Squeeze server:

1. Download and untar DjbDNS

debian:~# wget -q http://cr.yp.to/djbdns/djbdns-1.05.tar.gz debian:~# tar -zxvvf djbdns-1.05.tar.gz
...

2. Add DjbDNS users to /etc/passwd

Creating the below two users is not arbitrary but it's recommendable.

echo 'dnscache:*:54321:54321:dnscache:/dev/null:/dev/null' >> /etc/passwd
echo 'dnslog:*:54322:54322:dnslog:/dev/null:/dev/null' >> /etc/passwd

3. Compile DJBDNS nameserver

First it's necessery to use the below echo command to work around a common Linux bug:

debian:~# cd djbdns-1.05
debian:/root/djbdns-1.05# echo gcc -O2 -include /usr/include/errno.h > conf-cc

Next let's make it:

debian:/root/djbdns-1.05# make

4. Install the compiled djbdns binaries

debian:/root/djbdns-1.05# make setup check
# here comes some long install related output

If no errors are produced by make setup check this means that the djbdns should have installed itself fine.

As installation is compileted it's a good idea to report about the newly installed DjbDNS server if running a mail server. This info is used by Dan Bernstein to gather statistical data about the number of installations of djbdns servers throughout the world.

5. Do some general configurations to the newly installed DJBDNS

Now let's copy the list of the IP addresses of the global DNS root servers in /etc/.

debian:/root/djbdns-1.05# cp -rpf dnsroots.global /etc/ debian:/root/djbdns-1.05# ./dnscache-conf dnscache dnslog /etc/dnscache 0.0.0.0

dnscache-conf will generate some default configuration files for djbdns in /etc/dnscache

Next allow the networks which should be able to use the just installed djbdns server as a caching server:

debian:/root/djbdns-1.05# cd /etc/dnscache/root/ip
debian:/etc/dnscache/root# touch 192.168.1
debian:/root/djbdns-1.05# touch 123.123

First command will allow all ips in range 192.168.1.* to be able to access the DNS server and the second command will allow all ips from 123.123.1-255.1-255 to be able to query the server.

Some further fine tunning can be done from the files:

/etc/dnscache/env/CACHESIZE and /etc/dnscache/env/DATALIMIT

As a last step, before it's running, we have to link the /etc/dnscache to daemontools like so:

debian:/root/djbdns-1.05# ln -sf /etc/dnscache /etc/service/dnscache

If the daemontools is not linked to be accessible via /etc/service it's also a good to link it there:

debian:~# ln -sf /etc/service /

Now the DJBDNS should be running fine, to test if it's running without errors through daemontools I used:

debian:~# ps ax|grep -i readproc
5358 pts/18 R+ 0:00 grep -i readproc
11824 ? S 0:00 readproctitle service errors: ...........

If no errors are displayed it's configured and running to also test if it's capable of resolving I used the host command:

debian:~# host pc-freak.net localhost
Using domain server:
Name: localhost
Address: 127.0.0.1#53
Aliases:

pc-freak.net has address 83.228.93.76
pc-freak.net mail is handled by 0 mail.pc-freak.net.

Now the DJBDNS is properly installed and if you test it for a while with time host somehost.com localhost , you will see how quick it is in resolving.

The advantage of running DJBDNS is it does not require almost no maintance, its rock solid and great just like all other Dan Bernstein's written software.
Enjoy 😉

How to fix a broken QMAIL queue with queue-repair and qmhandle

Friday, May 27th, 2011

How qmail works, qmail queue picture :)

The aim of this small post is to give just a brief idea of how I fix my qmail server after breaking it or in case it is broken after mail bomb attacks, etc.

Most common cases when I break my qmail queue myself, are after I’m implementing some new patches and reinstall parts of the qmail server with a patched version of default qmail binaries.
On other occasions, I simply used the qmailctl to start or stop the server as a part of some routine tasks necessery for the administration of the qmail server.

Everybody who has already experience with qmail should have experienced, that qmail is very fragile and could break even with a simple changes, though if it works once it’s rock solid piece of mail servant.

Below I explain few ways I used through my days as a qmail sys admin to deal with broken or messed queues.

1. Fixing a broken qmail queue using automatic tools There are few handy tools which in most cases are able to solve issues with the queue, one very popular one isqueue-repair – check http://pyropus.ca/software/queue-repair/.
Installation of qmail-repair is dead easy, but it needs to be installed from source as no official debian package is available:

linux:/usr/local/src# wget http://pyropus.ca/software/queue-repair/queue-repair-0.9.0.tar.gz
linux:/usr/local/src# tar -xzvvf queue-repair-0.9.0.tar.gzdrwxr-xr-x charlesc/qcc 0 2003-10-22 16:54 queue-repair-0.9.0/
-rw-r--r-- charlesc/qcc 268 2003-10-22 16:54 queue-repair-0.9.0/TODO
-rw-r--r-- charlesc/qcc 1700 2003-10-22 16:54 queue-repair-0.9.0/CHANGELOG
-rw-r--r-- charlesc/qcc 18007 2003-10-22 16:54 queue-repair-0.9.0/COPYING
-rw-r--r-- charlesc/qcc 1098 2003-10-22 16:54 queue-repair-0.9.0/BLURB
-rwxr-xr-x charlesc/qcc 26286 2003-10-22 16:54 queue-repair-0.9.0/queue_repair.py

To check if there are issues fixable within the qmail queue it’s as easy as:

linux:/usr/local/src# cd queue-repair-0.9.0
linux:/usr/local/src/queue-repair-0.9.0# ./queue-repair -t
...
checking files...
checking queue/mess files...
checking split locations...

The tool will walk through the mail sub-directories containing mail queued files in /var/qmail/queue and will list any issues found.
It’s recommended that the qmail server is stopped before any queue modify operations are issued on the server:

linux:/usr/local/src# qmailctl stop
...

Further on in order to solve any found issues with the queue, there is the “-r”/repair option:

linux:/usr/local/src/queue-repair-0.9.0# ./queue-repair -r
...

Another tool which comes handy whether a repair of a messed qmail queue is needed is qmhandlehttp://sourceforge.net/projects/qmhandle/

The use of qmhandle is also pretty easy, all one has to do is to follow the usual classical steps of a download the source & compile:

linux:/usr/local/src# wget http://www.pc-freak.net/files/qmhandle-1.3.2.tar.gz
linux:/usr/local/src# tar -zxvvf qmhandle-1.3.2
...
linux:/usr/local/src# cd qmhandle-1.3.2

Once again it’s necessery that the qmail server is stopped via its init script before qmHandle tool is used, e.g.:

linux:~# qmailctl stop
...

There is a difference between qmail queue repair tool and qmail handle , while qmail queue-repair tool is used to fix improper permissions of queued files with the qmail queue, qmhandle ‘s application is to completely delete the stored mail contents of a broken queue.

Deleting all the qmail queue content is in some cases the only option to fix the queue.
Often such a drastic measure is required after a heavy mail server overload, let’s say a result of spammers or caused by virus infected mail users which send a massive amounts of spam mails.

Thus at many cases when queue-repair was unable to solve a queue mess, I use qmhandble and sacrifice all the queued emails by completely wiping them out like so:

linux:/usr/local/src/qmhandle-1.3.2# ./qmhandle -D
...

Above command would eradicate all queued emails. Hopefully after the qmail server gets launched again with qmailctl start all the mail server operations should be back to normal.

Note that the use of qmhandle’s queue delete capabilities is pretty dangerous, if you forgot to stop the qmail server before issuing the above command!

Note that in order to use both qmHandle and queue-repair tools you will need to install python interpreter as both of the tools are written in python.

To check what is currently in the queue in Qmail, there are also native tools available, as you should probably know if you have dealt with qmail, e.g.:

debian:~# qmail-qstat
debian:~# qmail-qstat
messages in queue: 2
messages in queue but not yet preprocessed: 0

Often when there are problems with Qmail and more specificly with qmail server queue the qmail-qstat command does show messages in queue, however when an attempt to check what kind of messages are in the queue with qmail-qread no messages are shown, for instance below you see an example of that, even though qmail-qstat claims 2 messages are in the queue, qmail-qread is unable to list the messages:

debian:~# qmail-qread
debian:~#

If all is fine with qmail queue above’s qmail-qread command should have returned something similar to:

debian:~# qmail-qread
26 May 2011 07:46:47 GMT #659982 3517 <hipo@pc-freak.net>
remote somemail@gmail.nl
26 May 2011 07:46:47 GMT #659983 3517 <hipo@pc-freak.net>

2. Fixing qmail queue manually This is very dangerous initiative, so before you try anything, make sure that you know what you’re doing, the possibility that you make the situation worst if you attempt to tamper manually the qmail queue is quite high 🙂

However if you’re still convinced to try fixing it manually, take a look at /var/qmail/queue it’s very likely that there are permission issues with some of the queued files, in order to fix the situation it’s necessery that the following directories:

/var/qmail/queue/mess/
/var/qmail/queue/remote/
/var/qmail/queue/bounce
/var/qmail/queue/info

gets explored with midnight commander / mc or some kind of convenient file explorer.

If there are queued files owned by users different from qmailq and user group qmail , for instance if owned by the root user, a simple chown qmailq:qmail to the wrong permissions file, should be able to resolve the issues.

Apart from all I explain above, there are many other ways suggested online on howto clean a qmail queue, one very popular one is using James’s qfixq shell script.

This script as of this very date is not working on Debian based systems, the script is dedicated initially to run on Fedora and Redhat based Linuces

Moreover myy experience with qfixq was never successful.

One very important note which is often a cause of many problems, is always make sure you stop and start the qmail server with an interval of at least of 10 seconds.

I’ve managed many servers which after an immediate (undelayed) qmailctl stop and qmailctl start was unable to run the whole engine of the qmail server (and either email sending or email receiving was not properly working) afterwards.

In that cases many weird behaviours are common, consider this seriously if you deal with the qmail-queue, it might happen that even if you have fixed your qmail queue, after a restart the qmail might breaks up.
I’ve experienced this kind of oddities numerous times, thus when I do changes to qmail I always make sure I restart the server a couple of times (at least 5 times 😉 ) always with a good delay between the HUPs.

And as always with qmail prayer is always needed, this server is complex, you never know what will happen next 🙂

How to edit, convert, join, split and re-time movie subtitle files on Linux (Fix Subtitles bad timing) / Install subtitle manipulation console tools for Linux

Tuesday, April 19th, 2011

As a Linux user I sometimes face difficulties with watching subtitled, movies. I mostly use Mplayer, Totem or VLC to watch the common video files.
The most common problems I face with subtitles are caused by bad timing, many times the solution to the bad timing issues is very simpleand comes up to changing the default movie player I use MPlayer to VLC or Totem.

However at many occasions trying to watch the movie with different kind of movie player does not help.
In this dark moments I get seriously irritated I am not a regular Windows user, where such kind of problems are almost none as many of the Windows movie player problems does fix bad timing issues automatically.

Luckily there is a work-around to this subtitles timing issues and other mishaps caused by guys who created a Movie subtitle files with a Windows subtitle editor program, subtitles timing, the Linux work-around takes a few more minutes to install a package called Subtitles

The Subtitles text utility is written in Perl and contains two executables subplay and subs .

Subtitles is the Linux subtitle Swiss Army Knife as it is capable of convert, join, split, and re-time of subtitles files

Installing Subtitles tools on Linux is a trivial job and it comes to download and installation of the 2 perl executables.
Here is how:

1. Download Subtitles.tar.gz toolsI have mirrored Linux Subtitles (Subtitles.tar.gz) here originally the binaries are to be found on URL address: http://karasik.eu.org/software/ , issue the commands:

linux:~# cd /usr/local/src
linux:/usr/local/src# wget http://www.pc-freak.net/files/Subtitles.tar.gz
...
2. Unarchive it

linux:/usr/local/src# tar -zxvvf tar -zxvvf Subtitles.tar.gz...
linux:/usr/local/src# cd Subtitles-1.0

3. Compile and install Subtitles system widePitily the Subtitles tools are not currently available as a packages in the repositories of Debian and Ubuntu Linux and thus easy installation without compilation via apt-get is unfortunately not available.

Here is the commands with which to compile and install Subtitles:

linux:/usr/local/src/Subtitles-1.0# perl Makefile.PL
...
linux:/usr/local/src/Subtitles-1.0# make
...
linux:/usr/local/src/Subtitles-1.0# make test
...

All tests successful.Files=1, Tests=17, 1 wallclock secs ( 0.05 usr 0.00 sys + 0.06 cusr 0.01 csys = 0.12 CPU)Result: PASS

linux:/usr/local/src/Subtitles-1.0# make install

Installing /usr/local/share/perl/5.10.1/Subtitles.pm
Installing /usr/local/man/man1/subplay.1p
Installing /usr/local/man/man1/subs.1p
Installing /usr/local/man/man3/Subtitles.3pm
Installing /usr/local/bin/subplay
Installing /usr/local/bin/subs
Appending installation info to /usr/local/lib/perl/5.10.1/perllocal.pod

Now as we have the subs executable installed, Let’s say your movie subtitles displays 5 seconds earlier before the movie scenes (bad timing), all you need to do to adjust your subtitles to show up in correct movie scenes is issue:

hipo@linux:/home/hipo/Movies$ subs -i -b 5 your_movie_subtitle_file_name.sub

now check out the subtitle files once again with your favourite player and the early subtitles display on your movie should be fixed.
Let’s have another scenario, say that your movie file is encoded to display 24 frames per seconds (fps) but the subtitle file is created to display the subtitles for a 25 fps, to solve this situation issue:

hipo@linux:~# subs -i -a 24/25 your_movie_subtitle_file.sub

Another possible scenario where subs command will be a precious asset is if you for example want to merge two subtitle files into one.Let’s say you have subtitles for a movie which are split over in 2 parts and the corresponding subtitles are in 2 different files, but eventually you find a better quality of the movie (DVD quality) in a single file and therefore you need the movie subtitles to be stored in one single file.
In that case to merge the subtitle files from let’s say the files movie_subtitle_file1.sub and movie_subtitle_file2.sub use the command:

subs -z movie_subtitle_file1.sub movie_subtitle_file2.sub

Some few other helpful things you can do with subs on Linux, are for example: splitting a file after a determined period of time, separating overlapped lines, and joining files into a single subtitle.

If you want to remove all the comments of gestures, facial expressions loud laughing etc. which displays usually the annoying (‘[Sneezing]’ or ‘[Music playing]) during the movie screen play, issue:

subs -e 's/[s-]*[.*]s*n*//gs' movie_subtitle_file.sub

Also other interesting Linux tool which is useful if you want to make conversions between subtitle in a (.sub) format to (.srt) format is called sub2srt perl script:

sub2srt’s home page is located on the URL address: http://www.robelix.com/sub2srt/, just to ensure it won’t just disappear with time I have created sub2srt mirror here

The most basic usage of sub2srt linux converting tool is by simply passing input sub and output srt file names like so:

linux:~# ./sub2srt 5rFF-pop.sub 5rFF-pop.srt

sub2srt supports changing of fps rate per second during conversion with the -f option as well as creationg of converted files in dos like end of file (CR+LF) with the –dos option.

Hope this article makes sense. If you find it useful, please drop me a thanks comment 😉

VIM Project (VI Improvied IDE Editor extension to facilitate web development with vi enhanced editor

Wednesday, August 25th, 2010

I use VIM as an editor of choice for many years already.
Yet it’s until recently I use it for a PHP ZF (Zend Framework) web development.

Few days ago I’ve blogged How to configure vimrc for a php syntax highlightning (A Nicely pre-configured vimrc to imrpove the daily text editing experience

This enhancements significantly improves the overall PHP code editing with VIM. However I felt something is yet missing because I didn’t have the power and functunality of a complete IDE like for instance The Eclipse IDE

I was pretty sure that VIM has to have a way to be used in a similar fashion to a fully functional IDE and looked around the net to find for any VIM plugins that will add vim an IDE like coding interface.

I then come accross a vim plugin called VIM Prokject : Organize/Navigate projects of files (like IDE/buffer explorer)

The latest VIM Project as of time of writting is 1.4.1 and I’ve mirrored it here

The installation of the VIM Project VIM extension is pretty straight forward to install it and start using it on your PC issue commands:

1. Install the project VIM add-on

debian:~$ wget http://www.pc-freak.net/files/project-1.4.1.tar.gz
debian:~$ mv project-1.4.1.tar.gz ~/.vim/
debian:~$ cd ~/.vim/
debian:~$ tar -zxvvf project-1.4.1.tar.gz

2. Load the plugin

Launch your vim editor and type : Project(without the space between : and P)
You will further see a screen like:

vim project entry screen

3. You will have to press C within the Project window to load a new project

Then you will have to type a directory to use to load a project sources files from:

vim project enter file source directory screen

You will be prompted with to type a project name like in the screenshot below:

vim project load test project

4. Next you will have to type a CD (Current Dir) parameter
To see more about the CD parameter consult vim project documentation by typing in main vim pane :help project

The appearing screen will be something like:

vim project extension cd parameter screen

5. Thereafter you will have to type a file filter

File filter is necessary and will instruct the vim project plugin to load all files with the specified extension within vim project pane window

You will experience a screen like:

alt=”vim project plugin file filter screen” />

Following will be a short interval in which all specified files by the filter type will get loaded in VIM project pane and your Zend Framework, PHP or any other source files will be listed in a directory tree structure like in the picture shown below:

vim project successful loaded project screen

6. Saving loaded project hierarchy state

In order to save a state of a loaded project within the VIM project window pane you will have to type in vim, let’s say:

:saveas .projects/someproject

Later on to load back the saved project state you will have to type in vim :r .projects/someproject

You will now have almost fully functional development IDE on top of your simple vim text editor.

You can navigate within the Project files loaded with the Project extension pane easily and select a file you would like to open up, whenever a source file is opened and you work on it to switch in between the Project file listing pane and the opened source code file you will have to type twice CTRL+w or in vim language C-w

To even further sophisticate your web development in PHP with vim you can add within your ~/.vimrc file the following two lines:

" run file with PHP CLI (CTRL-M)
:autocmd FileType php noremap <C-M> :w!<CR>:!/usr/bin/php %<CR>
" PHP parser check (CTRL-L)
:autocmd FileType php noremap <C-L> :!/usr/bin/php -l %>CR>

In the above vim configuration directovies the character is a comment line and the autocmd is actually vim declarations.
The first :autocmd … declaration will instruct vim to execute your current opened php source file with the php cli interpreter whenever a key press of CTRL+M (C-m) occurs.

The second :autocmd … will add to your vim a shortcut, so whenever a CTRL+L (C-l) key combination is pressed VIM editor will check your current edited source file for syntax errors.
Therefore this will enable you to very easily periodically check if your file syntax is correct.

Well this things were really helpful to me, so I hope they will be profitable for you as well.
Cheers 🙂