What’s the word in open source news this week? Here’s the roundup.
Release Found: Red Hat Enterprise Linux 4 Update 2 and later
In order to setup device-mapper-multipathing an updated system with the package device-mapper-multipath is recommended.
This functionality does not exist in releases of Red Hat Enterprise Linux 4 prior to Update 2.
To set up device-mapper multipathing, edit the /etc/multipath.conf file. Comment out the following lines at the top of the file:
devnode_blacklist {
devnode "*"
}
For example:
# devnode_blacklist {
# devnode "*"
# }
It is recommended that a resizing procedure be tested before performing it on a filesystem that contains critical data. It is also strongly recommended that data backups are created and verified before resizing filesystems. To assist the reader in becoming familiar with the resizing procedure, the rest of this article describes a scenario in which un-partitioned disk space is used to test logical volume and ext3 filesystem resizing.
In this test procedure, first we create a new partition (/dev/hda2) using un-partitioned disk space. A new volume group (TestVG) and logical volume (TestLV) are then created using a physical volume created on the partition. An ext3 filesystem is then created on the logical volume, it is checked, and then mounted. A new physical volume (/dev/hda3) using the rest of the un-partioned disk space is then created and added to the volume group and logical volume. Finally, the filesystem on the logical volume is resized, and the integrity of the filesystem is checked. » Read more
Remember Barton George? If you kept up with our Summit posts, then you’re familiar with Sun’s Linux guy, who was all over Boston blogging, podcasting, and interviewing. He’s back home now, but still putting together podcasts from his trip. Catch the two newest ones: Talking with Zmanda’s CEO, Chander Kant and Chattin’ with The Linux Foundation’s Executive Director, Jim “Led” Zemlin.
Also just in from the Red Hat News blog: One of our legal counsel penned a reader’s guide to the Firestar settlement. Totally worth reading if you’re at all interested in IP, licensing, and–in particular–the defensibility of the GPL.
The Red Hat Enterprise Linux 5 Installation Number is a 16-character hexadecimal text string used during the installation process. The installation number enables a user to install the full set of supported packages included with the subscription. For a limited set of Red Hat Enterprise Linux subscribers, the installation number is also used to activate subscriptions for additional Red Hat products and services. It replaces the Subscription Number from earlier versions of Red Hat Enterprise Linux.
Why use an installation number?
The Red Hat Enterprise Linux 5 installation trees and ISO images, in addition to the core operating system, contain a number of optional components. The Installation Number entered by the user during the installation process guides the Installer to include the correct components that match the user’s Red Hat Enterprise Linux Subscription. With certain types of Subscriptions it is also used to activate the Subscription in Red Hat Network. When registering the system to Red Hat Network (RHN), the Installation number is used to automatically subscribe the system to the right child channels. Finally it can be used by the customer to verify compliance to the subscription and might be requested by Red Hat Support when reporting an incident. » Read more
Jaroslaw is a JBoss QA Engineer based in Poland, and recently published an introduction to Drools that he kindly shared with us. This second piece covers Drools (or JBoss Rules), the open source business rules engine… in this case combining it with Hibernate.
This article is presented here in its entirety (with a trackback). The original can be found on Jaroslaw’s site. This article is also available in German and Polish.
Drools evaluates facts which are present in the working memory. But could it also reason over data stored in a relational database? This feature would extend Drools’ range of applicability and since this is an often asked question in the mailing list, it’s worth to know the answer which sounds: “of course Drools can!”
Hibernate, one of the most favorite ORM tools, allows to handle data stored in a relational database. This article will describe how one can access a Hibernate session from inside the rule engine. I will use PostgreSQL as a data source. Besides that I will create two classes, Game and Player, having a many-to-many relationship. » Read more
One of our long-time writers introduced us to Jaroslaw, a JBoss QA Engineer based in Poland, and mentioned that he’d been working on some documentation we might find interesting. And, boy, do we! This first piece de-mystifies the complex world of rules engines. Whether you call it Drools, or JBoss Rules, or JBoss Drools… you still might want to know what it does and how it functions in your technical environment. (Not to mention that it’s just all kinds of logical and interesting–if you like brainteaser word puzzles or abstract math questions, this qualifies as pleasure reading.)
This article is presented here in its entirety (with a trackback). The original can be found on Jaroslaw’s site. This article is also available in German and Polish.
Either you’re a developer, architect or a business analyst, it’s worth to get familiar at least with the first chapter of this article. It contains an introduction into the world of rule engines, which increase the readability of certain applications and make them easier to manage and to maintain. It applies to apps that take decisions, which depend on events or a state of some objects.
This article contains an introduction to rule engines, a description of an installation of Eclipse IDE and a guide how to configure Eclipse with the Drools Workbench plug-in. » Read more
Before installing an update, make sure all previously released errata relevant to the system have been applied.
To use Red Hat Network (RHN) from Red Hat Enterprise Linux 2.1, 3, or 4, launch the interactive Red Hat Update Agent with the command:
# up2date
To find more information about the command line options available for up2date, use the command:
# man up2date
To use Red Hat Network (RHN) for Red Hat Enterprise Linux 5, launch the graphical Update tool with the command:
# pup
Alternatively, for a command-line interface, use the command:
# yum update
To find more information about the command line options available for yum, use the command:
# man yum
