DCE Enhanced Distributed File System for AIX

POWER access to data


The Enhanced Distributed File System (EDFS) for AIX(r) Version 1.3 provides enterprise file sharing combined with the power of the RISC System/6000(r) (RS/6000(tm)) family of workstations and servers. EDFS builds upon the base function of the Distributed File Services (DFS) product, part of the Distributed Computing Environment (DCE) technology from the Open Software Foundation(r), providing increased availability, manageability, and performance.




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?

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?

Higher levels of availability and performance The enhanced features of EDFS add additional levels of scalability and manageability to base DFS. EDFS also ensures higher availability through features such as the Local File System (LFS), which is a robust, log-based physical file system, and data replication across EDFS servers, which distributes server loads.

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:


Heterogeneous transparent file sharing

Uniform global namespace



Data consistency

Centralized administration

Data replication

Enhanced Distributed File System

NFS/DFS Authenticating Gateway

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.

For more information on the Enhanced Distributed File System, or the RS/6000 and AIX family, call your IBM marketing representative, IBM Business Partner, or IBM Direct: 1 800 IBM-CALL (1 800 426-2255). In Canada call 1 800 363-RISC (1 800 363-7472).

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

AIX, IBM, and RISC System/6000 are registered trademarks of International Business Machines Corporation.
UNIX is a registered trademark in the United States and other countries, licensed exclusively through X/Open Company, Limited.
RS/6000 is a trademark of International Business Machines Corporation.
All other products are trademarks or registered trademarks of their respective companies.

(c)International Business Machines Corporation 1994
IBM Corporation
Department 507
1133 Westchester Avenue
White Plains, NY 10604

Produced in the United States of America
All Rights Reserved

References in this publication to IBM products or services do not imply that IBM intends to make them available outside the United States.

IBM will continue to enhance products and services as new technologies emerge. Therefore, IBM reserves the right to alter specifications and other product information without prior notice. Please contact your local IBM marketing representative or an authorized dealer for information on specific standard configurations and options.

This equipment is subject to FCC rules. It will comply with the appropriate FCC rules before final delivery to the buyer.


[ RS/6000 home page | IBM home page | Order | Search | Contact IBM | Help | Copyright ]
Last modified: Tue Oct 25 15:36:14 CDT 1994