Windows Home Server

Windows Home Server, code-named Quattro, is a home server operating system from Microsoft. Announced on 7 January 2007, at the Consumer Electronics Show by Bill Gates, Windows Home Server is intended to be a solution for homes with multiple connected PCs to offer file sharing, automated backups, and remote access. It is based on Windows Server 2003 Service Pack 2.

Windows Home Server was released to manufacturing on 16 July 2007 and officially released on 7 November 2007. Power Pack 1 for Windows Home Server was released on 20 July 2008.

Features

 * Centralized Backup - Allows backup up to 10 PCs, using Single Instance Store technology to avoid multiple copies of the same file, even if that file exists on multiple PCs.
 * Health Monitoring - Can centrally track the health of all PCs on the network, including antivirus and firewall status.
 * File Sharing - Offers network shares for computers to store the files remotely, acting as a network-attached storage device. Separate categories are provided for common file types like Documents, Music, Pictures and Videos. The files are indexed for fast searching.
 * Printer Sharing - Allows a centralized print server to handle print jobs for all users.
 * Shadow Copy - Takes advantage of Volume Shadow Copy Services to take point in time snapshots that allow older versions of files to be recovered.
 * Headless Operation - No monitor or keyboard is required to manage the device. Remote administration is performed by using the Windows Home Server Console client software provided in the bundle. Also supports Remote Desktop connections to the server while connected to the same LAN.
 * Remote Access Gateway - Allows remote access to any connected PC on the network over the Internet.
 * Media Streaming - Can stream media to a Xbox 360 or other devices supporting Windows Media Connect.
 * Data redundancy - Guards against a single drive failure by duplicating data across multiple drives.
 * Expandable Storage - Provides a unified single and easily expandable storage space, removing the need for drive letters.
 * Extensibility through Add-Ins - Add-Ins allow third-party developers to extend the features and functionality of the server. Add-Ins can be developed using the Windows Home Server SDK, to provide additional services to the client computers or work with the data already on the server. Add-Ins can also be ASP.NET applications, hosted in IIS 6 running on WHS.
 * Server Backup - Backs up files which are stored within shared folders on the server to an external hard drive.

Technology
Windows Home Server is built on the same codebase as Windows Server 2003 SP2. It includes almost all technologies found in Windows Server 2003 SP2 but has been limited in some areas to remove unneeded complexity or limit its uses. It also includes some new capabilities not found in Windows Server 2003 SP2:

Home Server Console
While the underlying operating system is built on Windows Server 2003 SP2, the configuration interface is designed to be user friendly enough that it can be set up without prior knowledge of server administration. The configuration interface, called the Home Server Console, is delivered as an RDP application to remote PCs - while the application runs on the server itself, the UI is rendered on the remote system. The Home Server Console client application can be accessed from any Windows PC. The server itself requires no video card or peripherals; it is designed to require only an Ethernet card and at least one Windows XP or Windows Vista computer.

Drive Extender
Windows Home Server Drive Extender is a file-based replication system that provides three key capabilities:
 * Multi-disk redundancy so that if any given disk fails, data is not lost
 * Arbitrary storage expansion by supporting any type of hard disk drive (Serial ATA, USB, FireWire etc.) in any mixture and capacity
 * A single foldehttps://en.wikipedia.org/wiki/Hard_disk_drive#EXTERNALr namespace (no drive letters)

Users (specifically those who configure a family's home server) deal with storage at two levels: Shared Folders and Disks. The only concepts relevant regarding disks is whether they have been "added" to the home server's storage pool or not and whether the disk appears healthy to the system or not. This is in contrast with Windows' Logical Disk Manager which requires a greater degree of technical understanding in order to correctly configure a RAID array.

Shared Folders have a name, a description, permissions, and a flag indicating whether duplication (redundancy) is on or off for that folder.

If duplication is on for a Shared Folder (which is the default on multi-disk Home Server systems and not applicable to single disk systems) then the files in that Shared Folder are duplicated and the effective storage capacity is halved. However, in situations where a user may not want data duplicated (e.g. TV shows that have been archived to a Windows Home Server from a system running Windows Media Center), Drive Extender provides the capability to not duplicate such files if the server is short on capacity or manually mark a complete content store as not for duplication.

Additional information can be found on the Windows Home Server Technical Brief for Drive Extender

Computer Backup and Restore
Windows Home Server Computer Backup automatically backs up all of the computers in a home to the server using an image-based system that ensures point-in-time-based restoration of either entire PCs or specific files and folders.. Bare metal, full computer, restores are initiated through a restore bootable CD, file based restores are initiated through the WHS client software which allows the users to open a backup and "drag and drop" files from it. This technology uses Volume Shadow Services (VSS) technology on the client computer to take an image based backup of a running computer. Because the backup operates on data at the cluster level, single instancing can be performed to minimize the amount of data that travels over the network and that will ultimately be stored on the home server. This single instancing gives the server the ability to store only one instance of data, no matter if the data originated from another computer, another file, or even data within the same file.

Computer backup images are not duplicated on the server, so if a server hard drive fails, backups could be lost, however, of course, the original source machine should be available. The "Server Backup" feature added in Power Pack 1 does not include duplication of backup images.

Remote access
The system also offers an SSL secured web browser based interface over the Internet to the shared file stores. The release version offers access to the web interface via a free Windows Live-provided URL, which uses Dynamic DNS. The web interface also allows the uploading to and downloading of files from the content stores. However, there is a limit of 2 GB for a single batch of upload.

The system also acts as an RDP gateway, allowing remote control over the internet of supported internal machines on the home network. Currently supported systems are those which would normally support Remote Desktop: Windows XP Professional, Tablet and Media Center editions and Windows Vista Business, Enterprise and, Ultimate editions. The web interface also supports embedding the Remote Desktop ActiveX control, to provide remote access to home computers from within the web interface directly. Remote sessions can also connect to the Home Server console to configure the server over the internet.

Compatibility
Windows Home Server features integration with Windows XP and Windows Vista through a software installation. Files stored on Windows Home Server can also be available through a Windows share, opening compatibility to a wide variety of operating systems.

64-bit Windows client support was introduced in Power Pack 1. Though Windows XP Professional x64 isn't officially supported.

Integration of the file sharing service as a location for Mac OS X's Time Machine was apparently being considered, but upon Mac OS X Leopard's release, Apple had removed the ability to use the SMB file sharing protocol.

Windows Home Server has no Domain Controller capability and cannot join a Windows Server domain.

Minimum system requirements
The following minimum specs are needed: Additionally, the following are required for installation of the operating system only Dedicated devices will have the operating system pre-installed and may be supplied with a server recovery disk which reloads the OS over a network connection. Examples are HP MediaSmart.
 * 1.0 GHz Intel Pentium 3 (or equivalent) processor
 * 512 MB RAM
 * 80 GB internal hard drive as primary drive
 * 100 Mbit/s wired Ethernet
 * Bootable DVD drive or USB stick
 * Display
 * Keyboard and mouse

File corruption
Installations of Windows Home Server RTM suffer from a file corruption flaw whereby files saved directly to or edited on shares on a WHS device may become corrupted. Only the files that have NTFS Alternate Data Streams are susceptible to the flaw. The flaw leads to data corruption only when the server is under heavy load at the time when the file (with ADS) is being saved onto a share.

Backups of client PCs made by Windows Home Server are not susceptible to the flaw.

Even though the issue was first acknowledged in October 2007, Microsoft formally warned users of the seriousness of the flaw on 20 December 2007. Microsoft has issued a list of applications, including Windows Live Photo Gallery, Microsoft OneNote, Microsoft Outlook and SyncToy 2.0, which might trigger the flaw if they are used to edit the files on a WHS share directly.

This issue was fixed by Power Pack 1, released on July 21, 2008.

No native backup
Windows Home Server RTM does not include a mechanism for backing up files stored on the server. However, Power Pack 1 added the ability to back up files stored on the device to an external drive.. Additionally, users can subscribe to 3rd-party online services, for a fee.

Pricing
While some hardware manufacturers have developed dedicated boxes, Microsoft has also released Windows Home Server to enthusiasts via the usual OEM/System Builder route. Pricing has varied amongst resellers, from around US$150 to US$200. But it is now available for under $100.

Complete DIY systems can be built for as little as $379 (hardware + WHS OS)