Saturday, January 31, 2009

What is bbPress

What is bbPress?


bbPress is an internet forum package written in the PHP programming language and available under the GNU General Public License. bbPress is both open source and free software.

The project was created by Matt Mullenweg to support users of WordPress. Existing bulletin-board software was overly sophisticated for those requirements, so bbPress was created with the same focus as WordPress: a functional and extensible core, with all other capabilities delivered through plugins.

Release History:
The first official release occurred on Oct 14th, 2006 and it was labeled as version 0.72 "bix", a revision number which was chosen (rather after than arrived at). Supported features included built in support for Akismet, integration with the WordPress user database, and RSS feed support. Early reviews described the release as "minimalist"
The announcement of bbPress 0.73 brought with it improved rewrite rules, a new template, support for languages other than English, and an easy-to-use installer similar to WordPress.
The latest official release 0.80 "Desmond"added more features, such as better timezone configuration and forum deletion.

The development of bbPress is formally managed through an issue tracking system. Informal discussion and support is available on the bbPress development forum


Fast and light
Simple interface
Customizable templates
Highly extensible
Spam protection
RSS Feeds
Easy integration with your blog

Oracle Enterprise Linux

The Oracle Unbreakable Linux support program delivers enterprise-class support for Linux with premier backports, comprehensive management, indemnification, testing and more, all at significantly lower cost.

Both the Oracle Management Pack for Linux and Oracle Clusterware are free for Oracle Unbreakable Linux support customers. Oracle Validated Configurations provide best practices for easier, faster, and lower-cost Linux deployment.

With Oracle VM—a faster, lower cost server virtualization product—customers now have a single point of enterprise-class support for their entire virtualization environments.

Friday, January 9, 2009

Local YUM Repository

Sometimes, especially when you create your own RPMs, it is extremely useful to keep them in a local YUM repository. The advantage of this is that, when you install a package, YUM automatically resolves any dependencies, not only by downloading the necessary packages from the other repositories you might have in you list, but also by using your local repo as a resource for potential dependencies.

So, when installing a package (eg my_package.rpm) with YUM, you are supposed to have already created RPM packages for all of the my_package.rpm’s dependencies and to have updated the repository’s metadata, so that yum is able to resolve all the dependencies. If these dependencies do not exist in any of the repositories in your list, then, in short, you cannot install your package with yum.

How to create a local YUM repo

You will need an utility, named createrepo. Its RPM package exists in Fedora Extras. To install it, just run as root:

# yum install createrepo

Then put your all custom RPM packages into local directory (I am going to copy this RPMS on my apache web directory path). This command copy all RPMS on your CDROM to local system disk

#cp /mnt/cdrom/RedHat/RPMS/*.rpm /var/www/html/local_Redhat_repo

After copying run this command to create metadata for repo, This command will create new with name "repodata" inside /var/www/html/local_Redhat_repo

#createrepo /var/www/html/local_Redhat_repo

Now restart your apache webserver

#service httpd restart

Create new file in /etc/yum.repos.d/local.repo and add this line in that file

name=RedHat-$releasever - Base

Now to test this setup run this command

#yum install list
#yum grouplist
#yum install .rpm

Notes:- I am using HTTP server on my setup but you can use NFS, SMB, FTP or Local directory to access repo

Wednesday, January 7, 2009

EMC Powerpath Software

I am having a lot of servers actually connected to various EMC storages like Symmetrix, Clariion. As with all storage softwares, the biggest challenge is to manage the multi-path devices and to ensure that devices remain on OS even in case of a Service processor failure or an HBA card failure.

As with all other storages like HP, SUN etc. EMC provides a software known as EMC Powerpath. This software allows one to map the OS devices to a pseudo block device without having to worry about the device paths.

For e.g. on a Linux system, HBA card 1 can give a device name as /dev/sda and the same device via HBA card 2 could have /dev/sdf or some other name. This setup can be really confusing if someone decides to use the devices on the basis of there SCSI device IDs. Lets say someone uses /dev/sda and due to power outage or service processor failure on SAN switch, the paths gets reversed. In that case,

/dev/sda will no longer be primary.
/dev/sdf will become primary.

But due to this path change, /etc/vfstab (Solaris) and /etc/fstab (Linux) configs would go foo-bar.

To save us from this hassel, EMC powerpath maps the OS block devices with the pseudo /dev/emcpower[a-z] devices.

This mapping can be checked using the command:-

powermt display dev=all

Powerpath software saves the device mapping info in a file /etc/opt/emcpower/emcpower.conf or /etc/emcp_devicesDB.idx & /etc/emcp_devicesDB.dat depending upon the versison of Powerpath software.

These mapped devices emcpower[a-z] can be partitioned & used for a filesystem (by running mkfs on them) or even as a rawdevice. It really boils down to how you wanna use them.

Always use emcpower pseudo devices in /etc/fstab or /etc/vfstab configurations or in /etc/sysconfig/rawdevices (For raw device mapping).