Archive for January, 2013

Display package information using rpm - RPM Package Manager

-i, –info
Display package information, including name, version, and description. This uses the –queryformat if one was specified.

-f, –file FILE
Query package owning FILE.

Description :
This package contains a system utility (passwd) which sets or changes passwords, using PAM (Pluggable Authentication Modules) library.

fedora@fedora ~> sudo rpm -qif /bin/passwd
Name : passwd
Version : 0.78.99
Release : 1.fc17
Architecture: i686
Install Date: Wed 23 May 2012 02:11:02 AM IST
Group : System Environment/Base
Size : 380177
License : BSD or GPLv2+
Signature : RSA/SHA256, Sat 28 Jan 2012 08:00:49 AM IST, Key ID 50e94c991aca3465
Source RPM : passwd-0.78.99-1.fc17.src.rpm
Build Date : Fri 27 Jan 2012 07:11:36 PM IST
Build Host :
Relocations : (not relocatable)
Packager : Fedora Project
Vendor : Fedora Project
Summary : An utility for setting or changing passwords using PAM

Red Hat Enterprise Linux 64-Bit Support

Red Hat Enterprise Linux 6 supports 64-bit processors; these processors can theoretically use up to 18 exabytes of memory. As of general availability (GA), Red Hat Enterprise Linux 6 is tested and certified to support up to 8TB of physical memory.

The size of memory supported by Red Hat Enterprise Linux 6 is expected to grow over several minor updates, as Red Hat continues to introduce and improve more features that enable the use of larger memory blocks. Examples of such improvements (as of Red Hat Enterprise Linux 6 GA) are:

Huge pages and transparent huge pages

Non-Uniform Memory Access improvements


What Is Apache Hadoop?

What Is Apache Hadoop?

The Apache™ Hadoop® project develops open-source software for reliable, scalable, distributed computing.

The Apache Hadoop software library is a framework that allows for the distributed processing of large data sets across clusters of computers using simple programming models. It is designed to scale up from single servers to thousands of machines, each offering local computation and storage. Rather than rely on hardware to deliver high-avaiability, the library itself is designed to detect and handle failures at the application layer, so delivering a highly-availabile service on top of a cluster of computers, each of which may be prone to failures.

The project includes these modules:

Hadoop Common: The common utilities that support the other Hadoop modules.
Hadoop Distributed File System (HDFS™): A distributed file system that provides high-throughput access to application data.
Hadoop YARN: A framework for job scheduling and cluster resource management.
Hadoop MapReduce: A YARN-based system for parallel processing of large data sets.

Unicast Addressing
Unicast delivery requires that a message should be addressed to a specific recipient. This is the most common type of messaging, so this addressing capability is present in almost all protocols.

Broadcast Addressing
Broadcasts are normally implemented via a special address that is reserved for that function. Whenever devices see a message sent to that address, they all interpret it as “This message goes to everyone.”

Multicast Addressing
Multicasts are the most complex type of message because they require a means of identifying a set of specific devices that will receive a message. It is often necessary to create several such groups, which may or may not partially overlap in their membership. Some mechanism is needed to manage which devices are in which groups.

Anycast message
A new type of message-addressing method was defined as part of IP version 6 (IPv6): the anycast message. This term identifies a message that should be sent to the closest member of a group of devices.

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