October 26, 2009

What is Cloud Computing?

Cloud computing is a general term for anything that involves delivering hosted services over the Internet. These services are broadly divided into three categories: Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS).
A cloud service has three distinct characteristics that differentiate it from traditional hosting. It is sold on demand, typically by the minute or the hour; it is elastic -- a user can have as much or as little of a service as they want at any given time; and the service is fully managed by the provider (the consumer needs nothing but a personal computer and Internet access). Significant innovations in virtualization and distributed computing, as well as improved access to high-speed Internet and a weak economy, have accelerated interest in cloud computing.
A cloud can be private or public. A public cloud sells services to anyone on the Internet. (Currently, Amazon Web Services is the largest public cloud provider.) A private cloud is a proprietary network or a data center that supplies hosted services to a limited number of people. When a service provider uses public cloud resources to create their private cloud, the result is called a virtual private cloud. Private or public, the goal of cloud computing is to provide easy, scalable access to computing resources and IT services.
Infrastructure-as-a-Service like Amazon Web Services provides virtual server instances with unique IP addresses and blocks of storage on demand. Customers use the provider's application program interface (API) to start, stop, access and configure their virtual servers and storage. In the enterprise, cloud computing allows a company to pay for only as much capacity as is needed, and bring more online as soon as required. Because this pay-for-what-you-use model resembles the way electricity, fuel and water are consumed, it's sometimes referred to as utility computing.
Platform-as-a-service in the cloud is defined as a set of software and product development tools hosted on the provider's infrastructure. Developers create applications on the provider's platform over the Internet. PaaS providers may use APIs, website portals or gateway software installed on the customer's computer. Force.com, (an outgrowth of Salesforce.com) and GoogleApps are examples of PaaS. Developers need to know that currently, there are not standards for interoperability or data portability in the cloud. Some providers will not allow software created by their customers to be moved off the provider's platform.
In the software-as-a-service cloud model, the vendor supplies the hardware infrastructure, the software product and interacts with the user through a front-end portal. SaaS is a very broad market. Services can be anything from Web-based email to inventory control and database processing. Because the service provider hosts both the application and the data, the end user is free to use the service from anywhere.

October 7, 2009

What are the SCCM 2007 Site System roles?

SCCM 2007 supports the following 14 Site System roles, with those prefixed with being new to SCCM:

Site Server - The server on which you install the SCCM software.
Site Database Server - The server running SQL and hosting the SCCM Site Database (only required for Primary Sites)
Configuration Manager Console - The interface for administering SCCM. Installed by default on Primary Site Servers this role can also be installed on workstations to allow remote administration.
SMS Provider - The intermediate Windows Management Instrumentation (WMI), layer that sits between the Configuration Manager Console and the Site Database (the Configuration Manager Console accesses the Site Database via the SMS Provider). Only required for Primary Sites.
Component Server - All SCCM Site System roles (except for the Distribution Point (DP)), requires SCCM-specific software to be installed in order for the Site System role to function. When such software is installed on a computer that computer becomes a Component Server.
Distribution Point (DP) - Stores SCCM Packages from where Clients can access them to install them. Only required for the Software Distribution, Software Updates, and Advertised Task Sequences functions of SCCM.
[NEW] Fallback Status Point - A "catch all" Site System for Clients that cannot be installed because of various issues such as assignment, or their inability to communicate with their Management Point (MP). Not required by default, but recommended to help with Client installation issues.
Management Point (MP) - SCCM Clients do not communicate directly with the SCCM Site Server and vice versa. Instead all communication is facilitated via the Management Point. A Default Management Point needs to be defined in every Site that has Intranet Clients.
[NEW] Pre-boot Execution Environment (PXE) Service Point - The Site System that responds to any computers requesting deployment of their Operating System (OS), via a PXE request. Only required if Operating System Deployments (OSD), are going to take place using PXE boot requests.
Reporting Point (RP) - Hosts the Report Viewer component that provides the web-based reporting functionality of SCCM. Only required if Reports need to be run on a particular Primary Site.
Server Locator Point (SLP) - Responsible for informing SCCM Clients which MP they should access in order to install the SCCM Client software. Only required in some Client Deployment scenarios.
[NEW] Software Update Point (SUP) - Assigned to the computer running Windows Server Update Services (WSUS). Only required if the Software Updates feature is going to be used.
[NEW] State Migration Point (SMP) - Stores the user's state migration data when a computer's OS is migrated. Only required if the OSD feature is going to be used.
[NEW] System Health Validator Point (SHVP) - This role is assigned to the computer running the Network Policy Service. Only required if the Network Access (NAP) feature is going to be used.