Chapter 7 Configuring & Managing Distributed File System

7.1 DFS Overview What is the Distributed File System? How DFS Namespaces and DFS Replication Work DFS Scenarios Types of DFS Namespaces What are Folders and Folder Targets? Namespace Server Requirements

What is the Distributed File System? The Distributed File System incorporates technologies that provide fault-tolerant access to geographically dispersed files DFS technologies include: DFS Namespaces - provide a virtual view of shared folders located on different servers DFS Replication - provides high-availability and fault-tolerance to files and folders Remote Differential Compression - provides a compression technology that is optimized for data transfers over limited-bandwidth networks

How DFS Namespaces and DFS Replication Work User in New York Server in New York 2 1 \\Contoso.com\Marketing DFS Replication \\NYC-SRV-01\ProjectDocs Folder Targets \\LON-SRV-01\ProjectDocs Namespace User in London Server in London User types: \\contoso.com\marketing Client computers contact a namespace server and receive a referral 1 Client computers cache the referral and then contact the first server in the referral 2

DFS Scenarios

Types of DFS Namespaces Characteristics Domain-based Stand-alone Path \\Domainname\Namespace \\Servername\Namespace Location Active Directory & memory cache Server registry & memory cache Size up to 5000 folders with targets in Windows 2000 Server mode up to 50000 folders with targets in Windows Server 2008 mode Up to 50000 folders with targets Availability Namespaces hosted on multiple servers Server cluster DFS Replication Supported

What are Folders and Folder Targets? Folder targets include: Are the primary elements of a namespace Have at least one folder target Shared folders (\\server\share) Folders in a shared folder (\\server\share\folder) A path to another namespace (\\domainname\rootname) Namespace Server Folder Targets Root Folder Folders with Targets \\LDN-SRV-01\Tools London \\NYC-SRV-01\Tools New York \\NYC-SRV-02\Training \\Contoso\Public Software Tools Training Guides

Namespace Server Requirements A namespace server is: A domain controller or member server Windows Server 2003 or Windows Server 2008 Namespace server considerations: Must contain an NTFS volume to host the namespace Must be in the same domain if the namespace is domain-based Cannot be a clustered resources if the namespace is domain-based

7.2 Configuring DFS Namespaces Deploying Namespaces for Publishing Content Security Requirements for Creating and Managing a Namespace Increasing Availability of a Namespace Options for Optimizing a Namespace

Deploying Namespaces for Publishing Content To configure a namespace for publishing content: Create a namespace Create a folder in the namespace Add folder targets Set the ordering method for targets in referrals Optional tasks: Set target priority to override referral ordering Enable client failback Replicate folder targets using DFS-R You may also need to delegate the ability to create & manage namespace

Security Requirements for Creating and Managing a Namespace Task Group Create a domain-based namespace Domain Admins Add a namespace server to a domain-based namespace Manage a domain-based namespace Local Administrators on each namespace server Create a stand-alone namespace Local Administrators group on the namespace server Manage a stand-alone namespace Implement DFS replication

Increasing Availability of a Namespace Domain-based namespace: Specify additional namespace servers Stand-alone namespace: Create a stand-alone namespace as a cluster resource Folders: Specify additional folder targets Replicate folders using DFS Replication

Options for Optimizing a Namespace Methods for optimizing a namespace include: Rename or move a folder Disable referrals to a folder Referral cache duration Namespace polling

7.3 Configuring DFS Replication What is DFS Replication? What are Replication Groups and Replicated Folders? DFS Replication Requirements Scalability Considerations for DFS Replication Process for Deploying a Multipurpose Replication Group Understanding the Initial Replication Process Generating Diagnostic Reports and Propagation Tests

What is DFS Replication (DFS-R)? DFS-R – multimaster replication engine that supports replication scheduling & bandwidth throttling Uses remote differential compression to efficiently update files over a limited-bandwidth network Detects changes on the volume by monitoring the update sequence number (USN) journal Uses a staging folder to stage a file before sending & receiving it Uses a version vector exchange protocol to determine what files need to be synchronized Uses a conflict resolution heuristic of “last writer wins” for files that are in conflict & “earliest creator wins” for name conflicts Is self-healing & can automatically recover from failure

What are Replication Groups and Replicated Folders? A set of servers, known as members, that participate in replicating one or more replicated folders Can be configured for multipurpose or data collection purposes Replicated Folder A folder that is kept synchronized on each member Replication Group Connection Projects\Spec.doc Projects Proposals Member Proposals\Budget.xls Projects Replicated Folders Proposals

DFS Replication Requirements The Active Directory schema must include the DFS replication objects Servers must be Windows Server 2003 R2 or Windows Server 2008, & must have the DFS replication service installed Servers in a replication group must be in the same forest Replicated folders must be stored on NTFS volumes On server clusters, replicated folders must be located in the node’s local storage Antivirus software must be compatible with DFS Replication

Scalability Considerations for DFS Replication Each server can be a member of up to 256 replication groups Each replication group can contain up to 256 replicated folders Each server can have up to 256 connections The number of replication groups multiplied by the number of replicated folders multiplied by the number of simultaneously active connections must be kept to 1024 or fewer A replication group can contain up to 256 members A volume can contain up to 8 million replicated files, & a server can contain up to 2 TB of replicates files The max tested file size is 64 GB

Process for Deploying a Multipurpose Replication Group Select the type of replication group to create Specify the name and domain Add the replication group members Specify a topology Specify the replication group schedule and bandwidth Specify the primary member Specify the folders to replicate and the local path on member servers

Understanding the Initial Replication Process Replication of DFS Replication settings The primary member starts replication Files are moved to DfsrPrivate\PreExisting Files are compared and replicated Primary member designation is removed

Generating Diagnostic Reports and Propagation Tests Use the Diagnostic Report Wizard to: Create a health report Start a propagation test Create a propagation report

End of Chapter 7