NDMP: Beating the backup blues

When it comes to ensuring interoperability among different servers and backup software, the Network Data Management Protocol (NDMP) Task Force means business.

The task force is working on enhancements to its NDMP specification, which defines backup over the network from a network storage node to a backup media node. This is all controlled by the backup host. Released last fall by codevelopers Network Appliance, Inc. and Peripheral Devices Corp., NDMP Version 1 is endorsed by more than 25 vendors of file servers, backup software and tape libraries.

The enhancements will allow backup data to be directed to any NDMP-compliant network node. This gives the network administrator the ability to locate the backup device on the backup host or on a third node on the network, resulting in a three-way backup architecture.

Backing up on backup

Backup is complex. Network-based backup administration software offers an array of capabilities. These include configuration control, scheduling of various backup levels, tape media management, tape device control, autoloader robotics control, automatic discovery of the storage and backup media environment, and user interface to easily administer and monitor the backup process.

Backup also is heterogeneous. IS departments use many varied platforms and operating systems.

Decisions made at department, workgroup and project levels usually result in many different types of systems over time, but backup is often considered a centralized function that calls for an enterprisewide solution.

File servers must be backed up for disaster recovery and historical file recovery purposes. Administrators want the flexibility to choose the best backup solution to fit their particular requirements.

Administrators would like to be able to mix and match their choice of backup software with the array of file servers they use. However, the proprietary back-up agents often are not ported to all of the file servers that must be backed up.

Administrators also want backup-ready network-attached storage - they don't want to have to install backup agents.

However, the administration and control aspects of backup are usually not the core competency of the storage vendor. Storage vendors have to rely on third-party backup vendors to solve the complex aspects of backup.

Backup products vary, but most vendors' architectures are similar. Backup software on a centralized backup host can, over the network, direct a file server to send its data to a backup device, typically a tape or tape library.

The tape device may be physically attached to the file server host or backup host.

What is NDMP?

The NDMP Task Force launched its initiative in order to create an open standard protocol for network-based backup for network-attached storage. The protocol allows backup and network-attached file server vendors to focus investment on functionality instead of excessive porting.

It also gives users an unprecedented level of choice and interoperability.

NDMP addresses the problem of backing up networks of heterogeneous file servers, such as dedicated file servers, with several backup applications. Previously, backup vendors were required to port to and track many different platforms and operating system releases.

Now NDMP-compliant centralized backup administration applications can use an NDMP universal agent in the network-attached file servers.

The dedicated file server vendors must only be concerned with maintaining compatibility with one well-defined protocol. The backup vendors can place their primary focus on the sophisticated central backup administration software.

In place of the many proprietary and incompatible vendor-specific backup protocols, NDMP is an open protocol providing backup control and data primitives that can be used by all backup software and file servers.

The result provides powerful solutions to the problems of network administrators, file server vendors and backup vendors.

Boberg is senior director of strategic marketing at NetApp, a dedicated network file server com- pany in Santa Clara, Calif. He can be reached by phone at (408) 367-3017 or via the Internet at rich@netapp.com.