dfs-n overview and scalability

Storage Developer Conference 2009

© 2009 Microsoft Corporation. All rights reserved.

DFS-N Overview and Scalability

Saad AnsariTest Lead, Microsoft Corporation

Marcello HasegawaSoftware Engineer, Microsoft Corporation

Jose BarretoProgram Manager, Microsoft Corporation



Legal disclaimers

This presentation is for informational purposes only

Microsoft makes no warranties, express or implied,

in this presentation

Your actual performance will vary depending on

your specific environment and configuration

(including server hardware, network, storage,

namespace design and other factors)

2



Agenda

Overview of DFS Namespaces

Hardware/Topology

Customer Scenarios

Scenario Description and Results

Client Access (Referral)

Namespace Management – Add (Add Links)

Namespace Management – View (GetInfo)

Backup or Migrate Namespaces (Export)

Restore Namespace (Import)

Server Maintenance (Startup)

Summary

Resources / Q&A



DFS-N Basics

DFS-N is part of the SMB/CIFS protocol

Provides a service which lets clients access a file space on local and geographically distributed file servers

through a single, consistent, locally available folder structure

without user knowledge of the remote servers

with availability against namespace and storage failure

while being directed to optimal targets

Value Proposition: enables deployment of large numbers of servers while providing availability and the benefits of a single namespace



Issues / Benefits of DFS-N

Issues

Many file servers and shares confuse users and admins

Users access is slow when opening files over the WAN

File server maintenance causes service disruption

Consolidating file servers is complex

Benefits

Simplified data access – users see a simpler structure

WAN-aware – users accesses nearest copy of file

Increased availability – multiple targets for each share

Easier administration – including server consolidation



Why Use DFS-N?

Unified Namespaces

Single “drive to map” - reduce complexity for users

Easier management by administrators

High Availability

Multiple Targets

Zero-downtime maintenance

Add/Move servers with no user impact

Site Awareness

Access to nearest replica of the data

Load distribution



Reduce Complexity

M:

\\S1\Docs

N:

\\S2\Sales

O:

\\S3\Market

S1

S2

S3

S1

S2

S3

M:

\\NS\data\Docs

\\NS\data\Sales

\\NS\data\Market

Without DFS With DFS



Physical vs. Logical View

Physical Locations of Folders

S1

Software

Office

Visio

S2

Applications

Project

OneNote

Namespace: \\NS\data\apps

Structure That Users See

Apps

Office

Visio

Project

OneNote

Root

Folders



Server Maintenance

\\S1\AllDocs

\\S2\Docs2

DFS

\\S1\AllDocs

\\S2\Docs2

DFS

Users opens file

1

DFS has only\\S1\AllDocs as a target

2

Admin installs new server \\S23

User opens file6

Admin adds \\S2\Docs2 as a target

4

Server S1 is taken off-line5

Namespace: \\NS\data\docs

\\S1\AllDocs

Namespace: \\NS\data\docs

\\S1\AllDocs

\\S2\Docs2



Efficient Network Utilization

DFS

DFS Client

DFS Client

Chicago

Boston

\\S3\AllProp

\\S4\proposals

DFS-R

Namespace:

\\NS\data\props

\\S3\AllProp

\\S4\proposals



Main DFS-N Features

Multiple namespaces per namespaces server

Mix standalone and domain mode namespaces

Users transparently access nearest target, by site

Insite mode to access only targets in same site

Access-based enumeration

Script-based management via DFSUTIL.EXE

Diagnostics via DFSDIAG.EXE



New in DFS-N for WS2008

Windows 2008 Mode Domain Namespaces:

Eliminates 5,000 link target limit for domain namespaces

Supports over 50,000 link target (deployed internally at Microsoft)

Requires Windows 2003 Forest Functional Level

Requires Windows 2008 Namespace Servers

Access Based Enumeration (ABE) support

Users only see namespace folders they have access to

For both standalone and 2008 mode domain namespaces

Configured using DFSUTIL.EXE command-line tool

Improved diagnostics

In-box tools improved – DFSUTIL.EXE, DFSDIAG.EXE

System Center Operations Manager (SCOM) 2007 pack

Performance Improvements

Significant performance improvement over the 2003 version



New in DFS-N for WS2008 R2

Performance and Scalability Improvements

Tested with larger number of link targets per namespace

Performance improvements over 2008 (large namespace startup and sync)

Added DFS-N Performance Counters

Allows administrator to closely monitor DFS-N performance

Improved DFSDIAG

Command line help improved with detailed messages and examples

MMC Support for Access Based Enumeration (ABE)

Previous release supported this only via DFSUTIL.EXE command line

MMC Support for Enabling/Disabling of Namespace Root Referrals

Administrators can temporarily disable a namespace server

Useful for maintenance of DFS-N namespace servers

Previous release required removing/re-adding server or using command line



Types of DFS Namespaces

Type 2000 mode

domain (V1)

2008 mode

domain (V2)

Standalone

Name used on UNC path Domain Name Domain Name Computer Name

Where data is stored? Active Directory Active Directory Registry

Recommended max links 5,000 50,000+ 50,000+

High Availability Multiple Servers Multiple Servers Failover Cluster

Minimum OS version on

namespace servers

Windows Server

2000

Windows Server

2008

Windows Server

2000

Minimum AD function level 2000 Domain FL

2000 Forest FL

2008 Domain FL

2003 Forest FL

AD not required

Access-based enumeration No Yes Yes

Consolidation roots No No Yes



Agenda


Hardware/Topology

Customer Scenarios








Summary

Resources / Q&A



Test Hardware/Topology

HP ProLiant DL360

Xeon 2.33GHz

8 GB RAM

2 X Broadcom BCM5708CNetXtreme II GigE

Smart Array Controller



Test Methodology

Scope

Isolate the problem space within the product

Eliminate noise like network, latency

Measurements

Number of samples based on initial experiments

Trade off on time vs. number of samples

Additional samples preserve observed patterns

Your actual performance will vary depending on your specific

environment, like hardware, network, storage, namespace

design, etc.

17



Agenda


Hardware/Topology

Customer Scenarios








Summary

Resources / Q&A



Tested Customer Scenarios

Client Scenario


Admin Scenario








Agenda


Hardware/Topology

Customer Scenarios








Summary

Resources / Q&A




Root Target Server

User accessing DFS Namespace

Referral Request



Client Access (Referral) *

Root Target Server


Referral Request

Referral Response

* Referral request/response time for a link



Referral Time - V2 Domain



WS2008 R2

WS2008

Referral Time - V2 Domain

~same within

measurement error



Agenda


Hardware/Topology

Customer Scenarios








Summary

Resources / Q&A



Namespace Management – Add (Add Link)

Domain Controller

Root Target

NetDfsAdd()

via UI or DFSUTIL

Admin



Namespace Management – Add (Add Link)*

Domain Controller

Root Target

NetrDfsAdd()Admin

DFS Metadata Operation

* Add Link time



Add Link Time - V2 Domain



Agenda


Hardware/Topology

Customer Scenarios








Summary

Resources / Q&A




Domain Controller

Root Target

Admin

NetDfsGetInfo()

via UI or DFSUTIL



Namespace Management – View (GetInfo)*

Domain Controller

Root Target

NetrDfsGetInfo()Admin


* GetInfo time



NetDfsGetInfo() Time - V2 Domain



NetDfsGetInfo() Time - V2 Domain

WS2008 R2

WS2008

~same within

measurement error



Agenda


Hardware/Topology

Customer Scenarios








Summary

Resources / Q&A




Domain Controller

Root Target

NetDfsEnum()

Operation

Admin



Backup or Migrate Namespaces (Export) *

Domain Controller

Root Target

NetrDfsEnumEx()Admin


* Export time



DFS Export (Enum) – V1 vs. V2

37



DFS Export (Enum) – V2 Domain

38



Agenda


Hardware/Topology

Customer Scenarios








Summary

Resources / Q&A



Restore Namespaces (Import)

Domain Controller

Root Target

Multiple NetDfsAdd()

Admin



Restore Namespaces (Import) *

Domain Controller

Root Target

Multiple

NetrDfsAdd()

Admin

DFS Metadata Operations

* Import time



DFS Import – V1 vs. V2

5,000 links is recommended for v1



DFS Import – V2 Domain

50,000+ recommended for v2



Agenda


Hardware/Topology

Customer Scenarios








Summary

Resources / Q&A



Server Maintenance (Startup)*

Root Target 1 Root Target 2

Admin


* Service Restart Time





Admin


Server Failure or

Maintenance





Admin


Server Failure or

Maintenance

Failover





Admin




Namespace layout

Flat Hierarchical

49



DFS-N Service Startup Time (Flat)




DFS-N Service Startup Time (Hierarchical)

51




Agenda


Hardware/Topology

Customer Scenarios








Summary

Resources / Q&A



Summary

Namespace Links

Recommended

Tested Limits

(WS 2008 R2)

V2 domain-based 50,000+ 1.3 million

V1 domain-based 5,000 20,000

Standalone 50,000+ 500,000

Test V1 to V2

Improvement*

WS 2008 to WS 2008 R2

Improvement

Size 5K 50k 100K 500K

Startup Similar ~100% ~50% ~25%

Import ~300% Similar Similar ~300%

Export ~300% Similar Similar Similar

Referral Similar Similar Similar Similar

GetInfo Similar Similar Similar Similar

* Formula: (V1-V2)/V2*100



Agenda


Hardware/Topology

Customer Scenarios








Summary

Resources / Q&A



Resources / Q & A

Main web sites

http://www.microsoft.com/windowsserver2008/en/us/R2.aspx

http://www.microsoft.com/windowsserver2008/en/us/file-print.aspx

http://www.microsoft.com/dfs

Protocol Documentation

[MS-DFSC] – client access protocol

[MS-DFSNM] – server API and domain store

[MS-FSSO] – file access services system overview

http://www.microsoft.com/protocols

Blogs:

File Cabinet – http://blogs.technet.com/filecab

Jose Barreto – http://blogs.technet.com/josebda











http://blogs.technet.com/filecab

http://blogs.technet.com/filecab

http://blogs.technet.com/josebda



Thanks!

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dfs-n overview and scalability

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