Bala-Krishna » CentOS

Web Hosting With CloudFS Cloud Hosting Technology

Bala Krishna — Sat, 05 Jul 2008 12:16:42 +0000

Cloud Hosting Technology is advanced new technology adapted by few web hosting providers. The technology works over the fleet of computers called hosting cloud that built to meet certain goals set by the hosting provider.? In the cloud hosting, deployed application automatically inherit clustered processing, load-balancing, and redundant storage depend on the application requirement you are going to deploy. for example, if you are going to load .Net based application then the application will be set to processed on windows cluster. The process is completely automatic without user intervention. In the same way, Linux based application will be processed on Linux cluster.

This technology has several new features that certainly make the process of web development easier and faster:

Cloud Hosting manged over set of computer clubbed together to meet certain requirement. So there is No Server, OS or device virtually to setup or manage. User simply need to load your application and rest of the things handled automatically.
This technology is extremely flexible because provider are open to load lot of technology that beneficial for users to use. You can switch to different framework easily if you want to move from old technology framework you use.
Upgrades are very easy to achieve in Cloud Hosting Environment. The technology upgrade that is obsolesce allow user to adapt new technology quickly.

Fedora 9 Released

Bala Krishna — Wed, 14 May 2008 12:21:16 +0000

Finally Fedora 9 has been released. Fedora is a community supported operating system sponsored by Red Hat. It is maintained by fedora community members accross the world. Beside RHEL, Fedora is free, open to use and modify it to best suit your need. You are always open to distribute it.

New Features

GNOME 2.22 used in this release that includes webcam photo and video creation utility called Cheese.
Improved network filesystem support.
New improved international clock applet.
Google Calendar support and custom email labels in Evolution.
New Remote Desktop Viewer and improved accessibility features.
KDE 4.0.3 and Xfce 4.4.2 is included in this release.
NetworkManager 0.7 provides improved mobile broadband support, including GSM and CDMA devices, and now supports multiple devices and ad-hoc networking for sharing connections.
It is now enabled by default on installations from DVD, CD, the network, and Live images.
Supports partition resizing for ext2/3, NTFS filesystems.L
Live USB images support available.
FreeIPA makes managing auditing, identity and policy processes easier by providing web-based and command line provisioning, and administration tools to ease system administration. FreeIPA combines the power of the Fedora Directory Server with FreeRADIUS, MIT Kerberos, NTP and DNS to provide an easy, out of the box solution.
Next generation Ext4 support for better performance, higher storage capacity and several other new features.
Fedora 9 uses Upstart, an event-based replacement for the /sbin/init daemon.
Firefox 3 support for native look and feel and desktop integration.
By default now support and installed free and open source Java environment OpenJDK 6
OpenOffice.org 2.4 included with many new features.
Fedora 9 includes Perl 5.10.0 features a smaller memory footprint and other improvements.
Fedora 9 features a 2.6.25 based kernel.
Automatic report kernel crashes to http://www.kerneloops.org

Download

i386 – Install DVD
x86_64 – Install DVD
ppc – Install DVD
i386 – Install CDs
x86_64 – Install CDs
ppc – Install CDs

Check out more download option here

Uber Uploader ClipShare Rayzz Ostube Failed to Find File Length Error

Bala Krishna — Mon, 04 Feb 2008 11:54:52 +0000

You may receive “Failed To Find Flength File” error during file upload using uber uploader. The main cause of this problem is due to apache mod_security enabled on your host. Apache mod_security may prevent writing flength file duing file upload. This will cause uploder to determine file length for percentage calculation and uploader produce file length error.

Solution: This problem can be easily solve by turn off mod_security through .htaccess . We need to turn off mod_security for uploader directory. To solve this problem, create .htaccess file with the following line and upload file to the directory where uploader files reside.

# Turn off mod_security filtering.
SecFilterEngine Off

# The below probably isn�t needed,
# but better safe than sorry.
SecFilterScanPOST Off

How to add php code to word press blog widget

Bala Krishna — Thu, 24 Jan 2008 16:11:20 +0000

Word Press default widget does not allow you to use php code. You can do this by simply editing template files but this is not overall solution. By doing this you are loosing beauty of widget drag and drop functionality. The Samsarin PHP Widget available as plug-in that allow user to create new widget and add php code inline with text.

Installation & Usage

Go to the Samsarin PHP Widget website.
Download and Extract the zip file in wordpress plugins directory.
Enable the Samsarin PHP Widget from Admin Panel.
In your admin console, go to Presentation, and then go to Sidebar Widgets
Create number of PHP Widgets you are required to add.
Drag one of the available Samsarin PHP Widgets to your sidebar.
Click on the widget button add title and php code.
All you have done..

How to extract .gz file content by gunzip utility

Bala Krishna — Sun, 13 Jan 2008 18:43:52 +0000

Like the windows, gz is common compression utility in Linux. This guide is to extract content of the .gz file by gunzip utility. Here is the command to see and extract content of the gz file.

View gz file content

gunzip -c mybackup.gz

Extract file file content in another file. you can use different file extension depend on the content of file.

gunzip -c mybackup.gz > mybackup.sql

Compress the mybackup.sql file as mybackup.gz in the current directory.

gunzip -c mybackup.sql > mybackup.gz

Here is the full details of the gzip command.

Syntax

gzip [ -acdfhlLnNrtvV19 ] [-S suffix] [ name ... ]

gunzip [ -acfhlLnNrtvV ] [-S suffix] [ name ... ]

-a–ascii	Ascii text mode: convert end-of-lines using local conventions. This option is supported only on some non-Unix systems. For MSDOS, CR LF is converted to LF when compressing, and LF is converted to CR LF when decompressing.
-c–stdout–to-stdout	Write output on standard output; keep original files unchanged. If there are several input files, the output consists of a sequence of independently compressed members. To obtain better compression, concatenate all input files before compressing them.
-d–decompress–uncompress	Decompress.
-f–force	Force compression or decompression even if the file has multiple links or the corresponding file already exists, or if the compressed data is read from or written to a terminal. If the input data is not in a format recognized by gzip, and if the option –stdout is also given, copy the input data without change to the standard ouput: let zcat behave as cat. If -f is not given, and when not running in the back ground, gzip prompts to verify whether an existing file should be overwritten.
-h–help	Display a help screen and quit.
-l–list	For each compressed file, list the following fields: compressed size: size of the compressed file uncompressed size: size of the uncompressed file ratio: compression ratio (0.0% if unknown) uncompressed_name: name of the uncompressed file The uncompressed size is given as -1 for files not in gzip format, such as compressed .Z files. To get the uncompressed size for such a file, you can use: zcat file.Z \| wc -c In combination with the –verbose option, the following fields are also displayed: method: compression method crc: the 32-bit CRC of the uncompressed data date & time: time stamp for the uncompressed file The compression methods currently supported are deflate, compress, lzh (SCO compress -H) and pack. The crc is given as ffffffff for a file not in gzip format. With –name, the uncompressed name, date and time are those stored within the compress file if present. With –verbose, the size totals and compression ratio for all files is also displayed, unless some sizes are unknown. With –quiet, the title and totals lines are not displayed.
-L–licence	Display the gzip license and quit.
-n–no-name	When compressing, do not save the original file name and time stamp by default. (The original name is always saved if the name had to be truncated.) When decompressing, do not restore the original file name if present (remove only the gzip suffix from the compressed file name) and do not restore the original time stamp if present (copy it from the compressed file). This option is the default when decompressing.
-N–name	When compressing, always save the original file name and time stamp; this is the default. When decompressing, restore the original file name and time stamp if present. This option is useful on systems which have a limit on file name length or when the time stamp has been lost after a file transfer.
-q-quiet	Suppress all warnings.
-r–recursive	Travel the directory structure recursively. If any of the file names specified on the command line are directories, gzip will descend into the directory and compress all the files it finds there (or decompress them in the case of gunzip ).
-S .suf–suffix .suf	Use suffix .suf instead of .gz. Any suffix can be given, but suffixes other than .z and .gz should be avoided to avoid confusion when files are transferred to other systems. A null suffix forces gunzip to try decompression on all given files regardless of suffix, as in:gunzip -S “” * (. for MSDOS)Previous versions of gzip used the .z suffix. This was changed to avoid a conflict with pack.
-t–test	Test. Check the compressed file integrity.
-v-verbose	Verbose. Display the name and percentage reduction for each file compressed or decompressed.
-V–version	Version. Display the version number and compilation options then quit.
-#–fast–best	Regulate the speed of compression using the specified digit #, where -1 or –fast indicates the fastest compression method (less compression) and -9 or –best indicates the slowest compression method (best compression). The default compression level is -6 (that is, biased towards high compression at expense of speed).

Compile and Build FFMPEG on Windows Platform

Bala Krishna — Thu, 03 Jan 2008 06:26:45 +0000

Installing FFMPEG from the source in window platform is easy as you do for other window application. Here is the complete instructios how to build FFMPEG in windows. To install FFMPEG on windows you need to install third party MinGW and MSys library that is compatible with GCC. This library is required to build ffmpeg in windows and support shell to run commands.

Download MinGW and MSys

MinGW: MinGW Direct download link
MSys: MSys Direct download link
SF Link: Sourceforge MinGW MSys Package Download Page
FFMPEG: FFMPEG Download fully patched version

Building FFMPEG

It is time to install ffmpeg. Extract downloaded ffmpeg archive in c: folder. If you have not downloaded yet please download now then run MSys.bat file from C:\msys\1.0\ folder. This location will be depend on you MinGW and MSys installation. In the command prompt run the following commands:

$ cd c:/ffmpeg-0.4.7

$ ./configure –extra-cflags=”-mno-cygwin -mms-bitfields” –extra-ldflags=”-Wl,–add-stdcall-alias” –enable-mingw32 –enable-shared –disable-a52 –disable-pp –disable-ffserver –disable-ffplay
$ make

Clip-Share Upload Video Internal Server Error

Bala Krishna — Fri, 28 Dec 2007 15:54:52 +0000

Clip-Share is mature script to run your own video sharing website like YouTube. This script is available variety of features and options at low cost. Unfortunately, they don’t have good knowledge base to short out technical problems related to script installation. The common problem with Clipshare and other video sharing script is in video upload and? conversion module.? Here is the error i received while i tried to upload video. The script produce error in initialization of progress bar.

Error:? “returned status code 500 Internal Server Error”

Possible Solution:

Check cgi-bin directory and files permission. In the script, upload progress monitored by perl script so that cgi-bin directory and files inside directory should have 755 permission. Make the changes if applicable.
Check temp and video path setting in “cgi-bin/configs/uu_default_config.pm” file. It should point to correct folder.? Both these folder should be writable by webserver.
temp_dir? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? => ‘/home/domain/public_html/tmp/’,
upload_dir? ? ? ? ? ? ? ? ? ? ? ? ? ? => ‘/home/domain/public_html/video/’,
Check flvideo folder permission in your installation directory. It should be writable by webserver.

Setting up website in WHM server

Bala Krishna — Fri, 21 Dec 2007 05:30:38 +0000

WHM? is a Web Host Manager tool that allows server administrators to quickly and easily add new web hosting accounts on a WHM enabled Web server.? Here is steps to create new hosting account without hassle.

Log into WHM account with your username and password.
Click the Create a New Account link from the Account Functions menu.
Enter the domain name into the Domain field, and the username into the UserName field. The UserName field will initially default to a name based on the domain you enter, but you may change it if you wish.
Enter a password into the Password field, and the disk quota into the Quota field. The Quota field, measured in MegaBytes, controls how much hard-disk space the new account is allotted.
Decide whether to allow CGI access, Shell access and FrontPage extensions, then check the respective boxes accordingly.
Decide on limits for the following boxes and enter values for each in the text field for each: Max FTP Accounts, Max Email Accounts, Max Email Lists, Max SQL Databases and Max Sub Domains.
Enter the maximum bandwidth for the account (in MegaBytes) into the Bandwidth Limit field.
Click on “Create” button.

Managing users in Linux

Bala Krishna — Wed, 19 Dec 2007 07:14:39 +0000

Here is the very useful list of commands used to manage users.

su (1) – run a shell with substitute user and group IDs
useradd (8) – Create a new user or update default new user information
userdel (8) – Delete a user account and their files from the system. The command “userdel -r newuser” will remove the user and deletes their home directory.
usermod (8) – Modify a user account.
adduser(8) – Command used to add user accounts.
chage (1) – Used to change the time the user’s password will expire.
chfn(1) – Change a user’s finger information
chsh(1) – Change a user’s shell.
chgrp (1) – Changes the group ownership of files.
chown (1) – Change the owner of file(s ) to another user.
gpasswd (1) – Used to administer the /etc/group file.
groupadd (8) – Create a new group.
grpconv (8) – Creates /etc/gshadow from the file /etc/group which converts to shadow passwords.
grpunconv (8)- Uses the files /etc/passwd and /etc/shadow to create /etc/passwd, then deletes /etc/shadow which converts from shadow passwords.
groupdel (8) – Delete a group
groupmod (8) – Modify a group
groups (1) – print the groups a user is in
grpck (8) – Verify the integrity of group files.
id(1) – Print group or user ID numbers for the specified user.
newgrp(1) – Allows a user to log in to a new group.
newusers (8) – Update and create new users in batch form.
nologin (5) – Prevent non-root users from logging onto the system.
passwd (1) – Used to update a user’s password. The command “passwd username” will set the password for the given user.
pwconv (8) – Used to create the file /etc/shadow from the file /etc/passwd to convert to shadow passwords.
pwunconv (8) – Uses the files /etc/passwd and /etc/shadow to create /etc/passwd, then deletes /etc/shadow to convert from shadow passwords.

Convert video files to FLV using FFMPEG command

Bala Krishna — Tue, 18 Dec 2007 14:10:41 +0000

FFMPEG is a most popular command line tool to convert media files such as audio, video and images from one format to another. We are going to learn ffmpeg command usage to convert other media format to current most popular streaming FLV format. FFMPEG is cross platform tool and does not require any Gui, support several command line options to control your conversion. The other video format can not be played directly in web browser. A right way to publish your videos for viewing in a browser is using FLV wide acceptable format.

How to convert / FFMPEG usage command

Convert other video format to FLV

ffmpeg -i video.avi -ar 22050 -ab 32 -f flv -s 320×240 video.flv

-i input file name
-ar audio sampling rate in Hz
-ab audio bit rate in kbit/s
-f output format
-s output dimension

Convert other video to FLV with metadata

This require flvtool2 tool to be installed on your box.

ffmpeg -i video.avi -ar 22050 -ab 32 -f flv -s 320×240 – | flvtool2 -U stdin video.flv

Convert FLV vidoe to jpg image sequence

This command used to extract frame image sequence.

ffmpeg -i video.flv -an -r 1 -y -s 320×240 video%d.jpg

-i Input file name
-an disable audio
-r fps
-y overwrite file
-s output dimension

Convert particular frame to jpg

Return one particular jpeg image of the frame based on start and end time.

ffmpeg -i video.flv -an -ss 00:00:03 -t 00:00:01 -r 1 -y -s 320×240 video%d.jpg

-ss record start time
-t record end time last for

Return first frame of video as jpeg image.

ffmpeg -i video.flv -vcodec png -vframes 1 -an -f rawvideo -s 320×240 video%d.jpg