1. NAS Application Environment
Introduction
This lesson will introduce the applications most commonly found in NAS environments. The lesson will cover uses of Microsoft Exchange, office productivity applications, and collaborative software development. It will also cover CAD-CAM applications, home directories, backup and recovery, streaming media, filers, and databases.
Importance
Understanding the NAS application environments is important to the Cisco Systems Engineer (SE) working in the storage field in order to understand the relationship between NAS and other storage technologies such as Storage Attached Network (SAN) and Direct Attach Storage (DAS).
© 2003 Cisco Systems, Inc. All rights reserved. 1

2. Lesson Objective
Upon completion of this lesson, you will explain the applications most commonly found in NAS environments.
Performance Objective
Upon completion of this lesson, you will explain the applications most commonly found in NAS environments.
Enabling Objectives
List the application categories which use NAS most extensively
Describe two ways that Microsoft Exchange can use NAS
Describe the various office productivity applications that are used in a NAS environment
Describe collaborative software development in a NAS environment
Describe how CAD-CAM applications are used in a NAS environment and list major CAD-CAM application vendors
Explain the function of home directories in a NAS environment
Explain a generic example of a backup and recovery application in a NAS environment.
Explain the use of streaming media on both the server and client side
Explain the use of NAS filers in the delivery of web content
Discuss the use of databases in a NAS environment including problems and solutions.

3. Lesson Outline NAS applications Microsoft Exchange and NAS
Office productivity applications
Collaborative software development
CAD-CAM applications
Home directory servers
Backup and recovery applications
Streaming media servers
Web content delivery
NAS for databases?
Summary
Prerequisites
Curriculum Unit 1, all Module 1 lessons, Module 2 lesson "File Sharing for NAS and SAN", and the Module 3 lesson, "The Building Blocks of NAS."

4. NAS Applications Email servers Office productivity
Collaborative software development
CAD-CAM applications
Home directory servers
Backup and recovery applications
Streaming media servers
Web content servers
NAS Applications
Objective
List the application categories which use NAS most extensively.
Introduction
This section introduces the learner to the application types that are most suitable for use in a NAS environment.
Facts
In theory, almost any application can be deployed in a NAS environment. However, due to the file oriented nature of NAS data access, certain types of applications are better suited for NAS solutions. In practice, the following application categories are among those that use NAS most extensively:
servers
Office productivity
Collaborative software development
CAD-CAM applications
Home directory services
Backup and recovery applications
Streaming media servers
Web content servers
Practice
List the application types that tend to use NAS most extensively.

5. Microsoft Exchange and NAS
The Exchange clients receive and send mail via their respective Exchange servers
The NAS filer contains the Exchange databases for each of the Exchange servers
Microsoft Exchange and NAS
Objective
Describe two ways that Microsoft Exchange can use NAS.
Introduction
This section provides an overview of the two ways that Microsoft Exchange can use NAS:
To store the Exchange Database files on a NAS device rather than the local Exchange Server
To use the NAS device (and the Exchange Merge) to store transaction based backup data
Facts
The slide illustrates the concept of storing the database files associated with a Microsoft Exchange solution on a NAS device rather than the Exchange servers themselves. In this illustration the database files for multiple Exchange servers are stored on the NAS device. Note that the Exchange servers are not sharing a single database. Each of the Exchange servers still maintains its own database files.
The placement of the database files onto the NAS is possible because the Exchange server does not directly communicate with, or control, the file system or the disks that it uses. Instead, an application such as Exchange Server relies on the Windows operating system’s I/O Manager to interface with the file system and drives.
Continued…

6. Microsoft Exchange and NAS (cont.)1. 2.
Exchange
Server
NAS Filer
Exchange
Server
NAS Filer
User's mailbox
is corrupted!
ExMerge creates .pst files
Microsoft Exchange and NAS (cont’d)
Facts
One of the challenges faced with Microsoft Exchange is the recovery of lost data. Microsoft’s ExMerge utility can be used to export user mailboxes from the Exchange server to a NAS device. This can be done on a transaction by transaction basis. The diagram illustrates this process.
A separate .pst file is created on the NAS device for each mailbox managed by the Exchange Server. The advantage to doing this is apparent on the recovery side.
An Exchange user loses their mailbox
The .pst files that were created originally using the ExMerge utility are imported by the Exchange server.
The user's mailbox is restored. Restoring the mailbox information from the .pst files is faster than restoring the data from a backup of the database and appropriate transaction logs. 3.
Exchange
Server
NAS Filer 4.
Exchange
Server
NAS Filer
User's mailbox
is restored!
ExMerge imports .pst files
Microsoft Exchange Data Recovery

7. Office Productivity Applications
Small business and departmental file servers
MS Office applications
Centralized file storage, backup and recovery
Inexpensive “appliances”
Office Productivity Applications
Objective
Describe the various office productivity applications that are used in a NAS environment.
Introduction
This section introduces the learner to some of the the office productivity applications that are used in a NAS environment.
Facts
Low cost, entry level NAS “appliance” type devices are inexpensive—starting at $1000 or less—compared to enterprise level SAN products. Such inexpensive products are ideal for small businesses and departmental file servers. The NAS device provides centralized file storage and backup for applications and data for office productivity applications such as MS Office—Access, Word, Excel, and PowerPoint.
Practice
List the various types of office productivity applications used in a NAS environment.

8. Collaborative Software Development
Source code management
Access control & filtering
Coordination & tracking
ClearCase, RCS, CVS, SCCS, …
Collaborative Software Development
Objective
Describe collaborative software development in a NAS environment.
Introduction
This section introduces the learner to NAS use by software development teams.
Facts
NAS is used extensively by software development teams for source code management (SCM). SCM applications provide:
Access control (who can check out a file?)
Filtering (which version of the files can they see?)
Coordination (what if 2 people want to edit the same file?)
Tracking (who has checked out what?)
NAS systems for these environments must be extremely reliable and perform well as additional storage is added to them. Scalability may become an issue when these systems reach their maximum capacity.
Examples of SCM applications include:
Rational Software’s ClearCase (used extensively at Cisco)
Revision Control System (RCS)
Concurrent Versions System (CVS)
Source Code Control System (SCCS)
Practice
What are the features that SCM apps provide?
File
Large NAS System

9. CAD-CAM Applications Engineering design and rapid prototyping
3D modeling and image editing
Engineering analysis
AutoDesk, SofTech, Dassault, PTC, … 1 2 3
CAD-CAM Applications
Objective
Describe how CAD-CAM applications are used in a NAS environment and list major CAD-CAM application vendors.
Introduction
This section introduces the learner to the use of CAD-CAM applications in a NAS environment, as well major CAD-CAM vendors.
Facts
Similar to software development, Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM), efforts typically involve teams of engineers working on various aspects of a larger project. In these environments, several applications, or application modules, use the same data files sequentially or in multiple processes.
For instance, the first workstation in the diagram might create the initial design for a part of the overall project, the second workstation might perform a series of tests on the design and the third workstation might integrate this design into part of a larger design or module. These types of processes are common in the electronics, chip design, defense and biotech industries.
Continued…
Initial Design
System Test
Integration
File
Large NAS System

10. Home Directory Servers
Medium and large size corporations, schools and universities
Home directory is auto-mounted when user logs in
Home Directory Servers
Objective
Explain the function of home directories in a NAS environment.
Introduction
This section introduces the learner to the role of home directories using NAS.
Facts
When a Cisco engineer logs in to their UNIX server, their home directory is auto mounted, making it appear as if it is locally attached to their server. This auto mount capability allows the engineer to log into any Cisco server, from anywhere in the world, and still have access to the files in his or her home directory. The same is true at most large corporations and universities; the user’s home directory is not local to the terminal, PC or server they are using. In many cases, the actual home directories reside on a NAS subsystem.
Practice
What does a home directory server provide for users?
NAS Subsystem

11. Backup and Recovery Applications
NAS Servers
Application Servers
SCSI Backup
Devices
Backup and Recovery Applications
Objective
Explain a generic example of a backup and recovery application in a NAS environment.
Introduction
This section introduces the learner to a generic example of backup and recovery in NAS environment.
Facts
Backup and recovery applications are critical in a NAS environment. The numerous strategies for implementing backup and recovery are beyond the scope of this lesson. However the diagram above illustrates a common LAN based backup scenario commonly used in NAS environments. Backup devices are centralized and accessed via the LAN. This configuration provides better utilization of backup devices, and since fewer higher quality devices are used, the backups tend to be more reliable and provide greater automation capabilities. Disadvantages include: an increase in network traffic as backup information is sent across the LAN and: the backup/restore process may interfere with user access. Network backup involves the use of many entities, including a backup server, a data source (the client), a storage device (usually tape) and a network (usually TCP/IP).
Continued…
Backup
Server
LAN

12. Streaming Media Servers
Real Networks Real Server
Windows Media Services Steaming server
Apple QuickTime Streaming Server
Music and video services (Kazaa, etc.)
Web based news services
Stream Server
Streaming Media Servers
Objective
Explain the use of streaming media on both the server and client side.
Introduction
This section introduces the learner to the use of streaming media servers.
Facts
The demand for Internet media streaming services is growing rapidly and creating a need for streaming technologies that enable rapid content delivery while maximizing quality of service and minimizing costs. NAS vendors are addressing this challenge by deploying high speed filers that work closely with steaming servers to deliver large volumes of data rapidly over IP based networks to large audiences.
The streaming server typically runs software such as MS Windows Streaming Server, Apple QuickTime Streaming Server, or Real Networks Real Server.
On the client side, a streaming media player consists typically of the following components:
A streaming protocol decoder that communicates with the streaming server
A system bitstream decoder/controller (there might possibly be a decryption layer before the bitstream decoder)
Both a video and an audio compression decoder
An audio post processor (that corrects the audio data if audio data has been lost during the transport)
A video post processor
A GUI interface
An overall system controller
LAN/WAN
Clients
NAS Filer

13. Web Application and Content Servers
Web Content Delivery
Web Application and Content Servers
Yahoo, eBay, CNN, …
Web Content Delivery
Objective
Explain the use of NAS filers in the delivery of web content.
Introduction
This section introduces the learner to the use of NAS filers by ISPs and ASPs.
Facts
Large ISPs and ASPs frequently use NAS to share files among application and content servers in server farms. The NAS filers require high performance and the ability to support a large number of clients. Considering the 24x7 nature of web business, these NAS servers typically need a fault tolerant design with redundant servers and filers, RAID redundancy and active failover capabilities.
LAN/WAN
Clients
NAS Filers

14. NAS For Databases? Microsoft says NO!
IP ordering issues could corrupt data
Oracle and Network Appliance say YES!
Private Database to NAS over Gigabit Ethernet
NAS for databases?
Objective
Discuss the use of databases in a NAS environment including problems and solutions.
Introduction
This section introduces the learner to a generic example of backup and recovery in the NAS environment.
Facts
One of perceived weaknesses of NAS has been its lack of applicability for block-based I/O, which is used for most database storage. NAS solutions have not been as widely deployed for high-end enterprise databases.
The issue has been somewhat clouded in the market by Microsoft’s failure to support NAS for its database products. Microsoft has claimed that TCP and stateless protocols such as NFS were unreliable.
Meanwhile Oracle and Network Appliance have worked to prove that NAS can be very effective for database storage. It is important to note that Oracle and NetApp assume that gigabit ethernet and dedicated network segments will be used in order to reduce network latency issues. Typically, databases deployed in NAS environments tend to be found mostly in small and medium size enterprises.
Oracle Server
NAS with Gigabit Ethernet

15. Email Servers—Microsoft Exchange Practice
Practice - Microsoft Exchange and NAS
The diagram illustrates the use of MS Exchange in a NAS environment. Please give a brief explanation of the diagram and comment on the issues behind Microsoft's support position.

16. Backup and Recovery Applications Practice
Practice - Backup and Recovery Applications
Instructions
In the generic example of NAS backup shown above, data passes through the production LAN. Can you see a way to modify the design to implement a LAN-free backup?

17. CAD-CAM Applications Practice1 2 3
File
Large NAS System
Practice - CAD-CAM Applications
Instructions
Based on the diagram, describe the basic process that can be followed using CAD-CAM applications in a NAS environment
List major CAD-CAM vendors.

18. Streaming Media Servers Practice
List the main components of a simple streaming media network network and explain the role of each component.
Practice - Streaming Media Servers

19. NAS For Databases? Practice
Discuss the use of NAS as database storage, including vendors who argue for and against using NAS for databases.
Practice - NAS for databases?

20. Lesson Practice
A student was asked to explain what characteristics of an application make it suitable for NAS.
This is what he wrote:
Applications are suitable for use in a NAS environment when they require high speed access, but do not need to use the same data files sequentially or in multiple processes. In general, applications should access files to be well suited for NAS solutions. Because of NAS's lack of applicability for block-based I/O, it is not recommended for use with databases. Additionally, the high cost of NAS devices limits their use in small businesses.
Please critique this paragraph in light of what we have covered in this lesson.
Practice - NAS Application Environment
Additional Practice Questions
1. What are the primary challenges to deploying Exchange Server on NAS filers?
2. What are the drawbacks to running most database servers on NAS filers?

21. Summary This lesson presented these key points.
There are a wide variety of NAS application environments. These include:
Microsoft Exchange
Office productivity applications
Collaborative software development
CAD-CAM applications
Home directory servers
Backup and recovery applications
Streaming media servers
Web content delivery
Databases
Summary: NAS Application Environment
Review
This lesson introduced the applications most commonly found in NAS environments. The lesson covered uses of Microsoft Exchange, office productivity applications, and collaborative software development. It also covered CAD-CAM applications, home directories, backup and recovery, streaming media, filers, and databases.