Compaq Rolls Out First Taste of ENSA

In a short time frame of only a few weeks, Compaq Computer Corp. presented an overall roadmap for storage and released a storage and clustering solution for Windows NT-only environments that offers a glimpse of some of the upcoming technologies.

In a short time frame of only a few weeks, Compaq Computer Corp. presented an overall roadmap for storage and released a storage and clustering solution for Windows NT-only environments that offers a glimpse of some of the upcoming technologies.

Late last year, Compaq unveiled its Enterprise Network Storage Architecture (ENSA). The architecture aims for standards-based distributed pools of highly available storage that can be centrally managed and can cross platforms. "We want to create storage as a utility, so it’s almost [like] when you plug an appliance into a wall [and tap] electricity. Our goal is [to create] systems you can plug into the network and receive storage, irrespective" of the hardware and software in use, said Mark Sorenson, director of enterprise operations software at Compaq’s NT program office.

Compaq’s architecture has major resonance for the Windows NT world because of the company’s, and its Tandem and Digital acquisitions’, close ties to Microsoft, says Dan Kusnetzky, director of operating environments research at International Data Corp. (IDC, www.idc.com). "They have the ability to influence and work with Microsoft at a level that other vendors can’t. It’s not a pre-eminent position, but it means that Compaq is going to be a force to be reckoned with in this market."

A few weeks later, Compaq announced Compaq Storage and Cluster Software Extensions for Windows NT (CSCSE). Sorenson calls CSCSE a proof point for several technologies -- virtual disk management, snapshots, network disks and clustering features -- expected to play an important role in Compaq’s overall storage strategy. "CSCSE is really a brick in the wall of our ENSA products. It allows customers to begin to experience these features with current equipment." In the near term, the features in CSCSE are designed to help customers bring growing, dispersed NT data back under IT’s control, Sorenson says.

Virtual disk management is for centralizing storage in a geographically dispersed organization. The system administrator puts physical disks and hardware RAID arrays in one place and uses the software to create a pool of storage that combines all available capacity. Then the administrator partitions the pool into virtual disks and makes them accessible from a locally attached server or serves them over a network. Advantages of the technique include central management of storage that hosts the most important applications and the ability of IT to match disk size to application requirements. Administrators can also add disks to the pool while the system stays online.

Compaq’s snapshots are virtual copies of the data that look exactly like the original virtual disk and appear to the system as another disk. The administrator can serve out the snapshot to a dedicated backup server, eliminating the need to take the system offline for backup. Compaq made the snapshots writable, making it possible to duplicate production data for training, Y2K or application testing, data mining and Web servers.

Network disks build on Compaq’s virtual disks. Once a virtual disk is created, the administrator can make it accessible locally or by application servers out on the network. The application server recognizes the disk as local, allowing the installation of Windows NT applications directly on the served disk. In a clustered environment, the served resources can failover to another node.

Clustering features include distributed Microsoft Cluster Service (MSCS) cluster configurations and an availability manager. CSCSE turns the network into a storage interconnect for an MSCS cluster, allowing administrators to separate storage and cluster nodes by up to 100 miles. Compaq’s Availability Manager complements the standard Windows NT Performance Monitor. A graphical display shows the entire network from a single node and highlights any performance problems.

Kusnetzky says Compaq’s clustering extensions target availability of applications and data but leave something to be desired in making NT look like a single entity on the network. "It doesn’t resolve some of the problems that NT’s shared-nothing approach to clustering imposes," he says. Nonetheless, he finds promise in the technologies Compaq unveiled in the extensions. "When I look at the technological approach that Compaq is taking, this is one of the most advanced approaches."