DCE Enhanced Distributed File System for AIX

POWER access to data

Contents

• Highlights
• Feature/Benefit
• AIX DFS at a glance

Highlights

The AIX DFS:

• Ensures reliable concurrent access to data
• Provides a single view of the data from everywhere in the enterprise with the DCE global name services
• Provides scalable performance in both local and remote network environments
• Reduces network traffic and file server loading through client data caching

The AIX EDFS:

• Includes a log-based file system called the DCE Local File System (LFS)
• Accomplishes administrative operations, such as backup, relocation and replication, without disrupting users
• Provides superior access security and protection over traditional file sharing products

Business problem: access to data

Businesses have a need to share all kinds of data, including bulletin board notices, operations manuals, and even computer programs. Their goal is to store and manage the data centrally while making it easily and reliably available to users on the network.

The AIX EDFS allows data sharing with the reliability and manageability characteristics required by most corporations today. Because DFS is an application built on top of the DCE technology infrastructure, it inherits all of the underlying benefits -- security, scalability, availability, interoperability and the ability to operate over wide-area networks (WANs).

As corporations begin to "up-size" from today's departmental local area networks (LANs), they are looking for centralized administration and enterprise directory services. EDFS is designed to meet these needs.

A global view architected for performance

Users access and interact with DFS files in the same way they would their local files. (POSIX single-site file semantics, including byte-range locking, are preserved across the network.) All DFS files are part of a single global namespace. Users can access data anywhere in the network without knowing its physical location; they only have to know its name!

The data can actually reside in the DFS physical file system, LFS, or in a client's native file system, such as the AIX Journalled File System (JFS). The DFS server takes data stored by the physical file system and makes it available to clients through its file exporter. For example, Ms. Jones can export her private AIX JFS file called &period.&period.&period./ibm/fs/user/jones/notes and Mr. Brown, in a remote city, can access it with the same name. Network File System (NFS) clients can access unprotected DFS data or secured DFS data if they use the NFS/DFS Authenticating Gateway. AFS clients can access DFS data through a vendor gateway, such as Lan Server Novel^(r) and Apple^(r) file systems, which are possible in the future.

Each DFS client in the network accesses files through its cache manager. For example, when you first open a spreadsheet, it is cached into local memory or disk where it is available for subsequent use. What are the benefits?

• The user has very good response time
• The server machine has less work
• Network traffic is kept to a minimum

DFS maintains cache coherency among clients, ensuring data integrity. All of this is part of the basic DFS services in the AIX DCE Base S ervices product.

Why AIX DCE Enhanced Distributed File System?

Smart data organization and tools Administrative tasks are greatly simplified through the EDFS data organization and tools. The concept of data being contained in "filesets" provides a convenient way to group administrative tasks, such as data backup, relocation and replication. The EDFS filesets are location- independent, so they can be transparently replicated or moved to another aggregate for load balancing.

Centralized security control

EDFS uses DCE's Kerberos(tm) style of security to ensure that users are who they say they are. EDFS access control lists allow or deny users access to data and programs with a high degree of granularity. This is important for intercompany as well as intracompany collaboration and sharing of information.

AIX DCE EDFS at work

EDFS is very effective in making large amounts of data available to many users in an enterprise environment.

Here are some examples where you can effectively put the advanced features of EDFS to work for you as a repository for:

• Common documents
• Program binary code
• Intercompany bulletins
• Installation images
• Centralized GIS or CAD drawings

Feature/Benefit

Heterogeneous transparent file sharing

• DFS client/server architecture allows users to access files on remote DFS servers as if they were local

Uniform global namespace

• Clients can access data from anywhere in the network without knowing the location

Caching

• DFS caching of the data at the client machine allows more clients per server through reduced network and server loads

Security

• The DCE security server is used for authentication of DFS users
• EDFS provides fine-grained controlled access to files and directories

Data consistency

• DFS uses a standard protocol to ensure data coherency

Centralized administration

• Allows administrator to manage the distributed file system from any client workstation in the cell
• Provides facilities to automate time-consuming tasks

Data replication

• Provides high availability of user data through distributing and maintaining read-only copies on multiple machines around the network
• Improves performance because client requests can be distributed to the closest or least-busy server in the network

Enhanced Distributed File System

• Improves administration through fileset manipulations such as online relocation, replication and backup of data
• Provides a log-based physical file system that delivers fast restart and recovery after system startup or restart

NFS/DFS Authenticating Gateway

• Allows any NFS client to access protected DFS data with the intended level of security protection for user access

AIX DFS at a glance

Hardware requirements

All RS/6000 models configured with a minimum of one supported display with keyboard and mouse, or on supported ASCII terminal

Memory requirements*

Recommended minimum for all DCE programs is 32MB; DCE Base Feature for clients can run at 16MB but 32MB is recommended

Fixed-disk requirements** (approximate)

AIX DCE Base Services (client): 23MB + 10MB DFS Client Cache
AIX DCE Cell Directory Server: 25MB
AIX Security Server: 26MB
AIX DCE Enhanced Distributed File System: 27MB
AIX InfoExplorer(tm) publications: 25MB

Operating system

AIX Version 3.2.4 or greater

Packaging and installation

AIX DCE can be preinstalled on system fixed disk storage or shipped on magnetic tape

* These requirements do not take other application demands into consideration.
** Consult your IBM marketing representative for more current information, including paging space requirements.

You can also call 1 800 IBM-4FAX (1 800 426-4329), and more information will be faxed immediately to your location.

If you have access to the Internet, you can find additional information on IBM's Worldwide Web server at http://www.ibm.com

^(r)

AIX, IBM, and RISC System/6000 are registered trademarks of International Business Machines Corporation.

^(r)

UNIX is a registered trademark in the United States and other countries, licensed exclusively through X/Open Company, Limited.

(tm)

RS/6000 is a trademark of International Business Machines Corporation.

All other products are trademarks or registered trademarks of their respective companies.

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