The Mark of Zetta

A future version of Zetta Systems' storage-server architecture will expand its capabilities to remote block and file data replication.

By any measure, e-mail is the killer Internet application. But at the same time, many IT managers find it a killer app to back up: Dealing with dynamic data—as well as senior managements increased expectations of continuous availability—is a real headache.

In the past, demands werent quite so high. A server would go down and everyone would fret, for sure. But the IT team would rally together, and with some overnight overtime (and the best of luck), most everything would be restored in a day.

Nowadays, if the Microsoft Exchange server is knocked out of action, the CEO is on the phone in just a couple of minutes, breathing down your neck until everything is running correctly and returned to order. Such dynamic data services are critical even to smaller businesses.

This rising bar provided the backdrop for my recent discussion with Ganapathy "Krish" Krishnan, president and CEO of Zetta Systems of Woodinville, Wash. He offered a few details about Zetta Server Unified, the working title for the companys forthcoming storage appliance architecture that will provide continuous snapshots and replication for this dynamic data.

Due in the fourth quarter, the new appliance will sit between database servers running on the SAN and the servers and clients on an IP network. The system will support heterogeneous environments, Krishnan said, and offer managers a flexible approach to the backup and replication of critical, dynamic data sets and files that are changed less frequently.

"This separates the server and the storage; managers put [Microsoft] Exchange or SQL on their servers and use our box as an information store," Krishnan said. "Our server looks like a hard disk. And its completely transparent to the application—except that the intelligence is built in without a heavy overhead."

The Zetta appliance will support an effectively unlimited number of snapshots (up to 4 billion in number) and produce them very quickly, some within 100 milliseconds, Krishnan said. Customers could set up the server to take a snapshot every 30 seconds or so.

While capable of storing a practically unlimited number of snapshots, the Unified system will also support remote replication of both block and file data. This offers customers a very robust continuity capability: "If something happens, [managers] can move back in time [to an earlier snapshot] and Exchange will simply think that time has changed."

Krishnan said a terabyte database may experience 100MB of changes in a day, and the many megabytes of pointers needed to support that much data can slow performance of snapshots and backup. He pointed to current snapshot limitations in Windows Storage Server 2003s Volume Shadow Copy Services and Virtual Disk Service, which support up to 512 point-in-time snapshots, 64 per volume. While that may satisfy the needs of many applications, its a lot fewer than the billions of snapshots supported by Zettas architecture.

The company said it will target both large and mid-size enterprise companies for the product, moving into the Fortune 1000 space. A package with both hardware and software will be in the $20,000 to $40,000 price range.

The Zetta Server Unified performance will leverage the technology found in the companys current product lines, including a BSD-based operating system, journaled file system, and high- and low-level APIs for replication and snapshots. Yet it runs on off-the-shelf, Intel-based hardware platforms, supporting a wide range of storage.

(For more information, read Have NAS Your Way.")

In some ways, Zetta has taken a page from Microsofts book. Its product lives in a heterogeneous hardware environment. Furthermore, both companies develop an operating system. Zettas technology, however, is focused on storage and data continuity.

"Most network backup systems havent been architected from the ground up for snapshots," Krishnan said. "The secret sauce is how you arrange the data. We had the luxury of starting from scratch."

David Morgenstern is a longtime reporter of the storage industry as well as a veteran of the dotcom boom in the storage-rich fields of professional content creation and digital video.

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