Managing Storage over the Web

Managing Storage over the Web

Web-based storage management offers a wealth of potential benefits, including platform flexibility, reduced costs, and decreased network bandwidth consumption.

David Habermehl

Digital Equipment Corp.

Inexorable industry trends are conspiring to turn the task of managing network storage resources into a nightmarish proposition. As companies grow, networks comprise more complicated topologies that have more servers running more applications supporting more users. Network storage resources are becoming more sophisticated, numerous, and varied. And aggregate storage capacity is exploding, with typical increases of 70% to 100% annually.

The critical value of information is driving demand for continuous access to data, 24 hours a day, 365 days a year. As a result, administrators must be able to quickly respond to events and repair problems before access to data is interrupted. Oh, and by the way, the staff trying to accomplish this Herculean feat is usually shrinking! Most organizations we talk to at storage conferences are asking smaller administrative staffs to manage larger, more complex storage environments. Even worse, they want to ensure continuous availability of mission critical data and rapid recovery of data warehouses in decision support systems.

Clearly, the current situation calls for a quantum leap in management tools to enhance the productivity of beleaguered administrators of the enterprise`s storage assets. That advancement may well be the capability to use those tools over your company`s Web. Let`s look at what you need from storage management tools, how the current implementations fall short, and how the Web can bridge the gap.

What You Need

Within the world of storage, the focus is storage resource management (SRM). Michael Peterson, president of Strategic Research, a storage industry analyst firm in Santa Barbara, CA, defines SRM as "systems management for storage--a class of management tools integrated into a central administrator that discovers, tracks, monitors, optimizes, and manages storage resources throughout a network."

To set the stage for integrating SRM tools and the Web, we`ll briefly discuss the tools` general capabilities: monitoring, configuration, and reporting. In addition, we`ll describe the integration of SRM tools with network management infrastructures like Computer Associates` Unicenter TNG, Hewlett-Packard`s OpenView, and Digital`s ServerWorks. Finally, we`ll consider what may be the biggest contributor to an SRM tool`s acceptance at your site: How well does the tool fit your administrators` preferred style of operation?

Monitoring. The ability to monitor storage resources is critical to delivering 7 x 24 operation. This is how administrators spend most of their time, and it will determine whether they succeed or fail to provide continuous access to data for end-users. Downtime is very expensive, yet as the environment becomes more complex, problems are increasingly likely. Hence, administrators must have sufficient warning of potential problems with storage resources in order to ensure continuous access to data.

For successful monitoring, SRMs should be scalable and intuitive. Regardless of the complexity of the environment, SRM software must quickly push the right information to the right location or person and present it in a way that facilitates quick action and problem resolution. To achieve this, the tools must be built on a distributed and graphically intuitive foundation.

Configuration. Like its monitoring interface, an SRM tool`s configuration interface should be scalable and intuitive. The interface must make it easy to configure storage resources in large, far-flung enterprises managed by multiple administrators, for example, facilitating firmware updates on 2,000 disk drives through 50 controllers on 25 hosts in 5 different locations. While there are many facets to scalability, the SRM software must be distributed. By distributing software, administrators can manage remote resources from anywhere on the network, even from home.

While configuration is obviously a necessary task, it is also an infrequently performed task. For example, administrators do not need to reconfigure the RAID sets of 500 GB disk arrays very often. Since an SRM tool`s configuration interface is rarely used, administrators may be less familiar with it than they are with other parts of the tool, so its interface must be particularly intuitive.

Reporting. Reports are a fact of life for administrators, used either to verify to management that goals have been achieved (uptime, performance, etc.) or to validate requests for additional resources. This task also requires a distributed and graphical underpinning. Reporting requires data collected from remote objects, which is then consolidated and displayed in meaningful formats.

Integration. Proprietary SRM tools are increasingly being integrated with global network management infrastructures like CA Unicenter TNG, HP OpenView, and Digital ServerWorks. At the lowest level, a measure of integration is achieved via SNMP, the industry standard network management protocol. The SRM software maintains a management information base (MIB) and signals events via SNMP that are detected by the network management infrastructure. Typically, when the infrastructure receives an alert for a managed resource, it responds by changing the color of the resource`s icon on its console from green to red.

A more complete integration entails the ability to directly launch a proprietary SRM tool from a network management console, say, by double clicking the icon that has changed color. This mechanism is used by such platforms as CA Unicenter TNG to execute detailed, device-specific functions on, for example, storage devices like RAID sets and tape libraries. For this level of integration to work, the graphical and distributed underpinnings of the SRM tools must integrate with the network management infrastructure.

Flexibility. The issue of operational flexibility boils down to convenience. Can you run the SRM software from any of the operating systems you are using? Can you run it from any location on the network or are you pinned down to a few locations where a GUI front-end has been installed? Is it a "good network citizen" or does it consume excessive bandwidth? Is it easy to upgrade to a new version of the SRM tool? Can your administrators dial in from home to use the tool?

What You Get

SRM tools have been implemented in several ways. Each has significant strengths and shortcomings (see table).

GUI SRM management tools are typically either X Windows or Microsoft Windows applications. Both use "agent" programs, which run on the hosts to which the storage resources are attached. The agents act as intermediaries between the storage devices and the management tool. They accept commands from the software and interact accordingly with the storage devices and they pass status and configuration information from the devices back to the management tool (e.g., device ready/not ready, RAID set assignments, and device overheating).

Two significant advantages of the agent architecture are centralized administration of distributed storage resources and a consistent management interface regardless of the host platform. This permits administrators to use the same interface to manage, for example, NT-based storage and UNIX-based storage. However, there is still room for improvement. Some of the shortcomings of today`s GUI management tools include:

Microsoft Windows tools only run on Intel or Alpha systems; X Windows tools only run on UNIX platforms, X terminals, or systems with an X emulator.

Windows tools must be pre-installed on every system that may be used with SRM, which limits the flexibility of operation. This issue can be lessened with X Windows, but even then the software is usually installed on every system used for management.

In addition to limiting the flexibility of operation, the installation issue also makes upgrading management tools painful. For example, if you opt for operational flexibility by installing the tool on many systems in your network, you`ve opted for the pain of having to install the upgrade on each system.

X Windows tools usually require more costly UNIX systems and they consume prodigious amounts of network bandwidth.

Bridging the Gap

New SRM tools must be able to run on various platforms, be easy to install and upgrade, be low cost, and consume little network bandwidth.

Quite possibly, the way to meet these criteria may be to use the Web. Web-based management tools function much like traditional GUI tools, except the interface is presented through a browser. The rest of the architecture is much the same. Host-based agents communicate with a centralized management program that, in turn, presents an interface to the administrator. However, there is one valuable difference: The centralized management program resides on a single Web server on your network instead of on multiple management stations.

The Web-based approach addresses the shortcomings of traditional methods:

Platform flexibility. The Web provides a truly cross-platform console with Java-enabled browsers. Browsers are the ultimate "thin clients." They cover virtually every platform that can be used as a management station. In fact, management tools may be a common application for network computers.

But the most important contribution of the Web-based approach to flexibility is that the management tool can run anywhere on the network, simply by pointing the browser to a "storage resource management" Web page. Doing so automatically downloads the Java-based GUI to the browser, regardless of location or platform.

Ease of installation/upgrade. Unlike traditional approaches that require software to be installed on every system that may be used as a management station, the Web-based approach only requires the tool to be installed on a single system: one of the network`s Web servers. From that point on, the program can be run on any system on your network that has a browser. And when it`s time to install a new revision of the tool, only a single system needs to be upgraded.

Low cost. Web-based management tools run on any platform that supports a browser. That could be a cheap network computer, a relatively modest PC, or any other platform. In fact, instead of acquiring additional dedicated hardware, existing network systems can be used. The installation/upgrade benefits are also major money savers, as is training people on a single interface, even though they may run the tool on a variety of operating systems.

Low network bandwidth. Although the World Wide Web has sarcastically been tagged the World Wide Wait, this is much less of an issue with internal high-speed LANs than it is with WANs. In particular, Web-based tools consume significantly less network bandwidth than X Windows applications because they don`t transmit graphical data over the network like X Windows does. Yes, it does consume bandwidth to download Java code from the Web server to the browser, but this is only done once per management session. After that, network traffic is relatively modest.

Impact on Vendors/Integrators

The Web-based approach also provides benefits and challenges to storage vendors and systems integrators delivering these tools. On the upside, this approach reduces product development and maintenance costs and shortens the time to market.

By piggybacking on the existing Web infrastructure, vendors and systems integrators can focus on true storage resource management issues instead of developing distributed infrastructures. Also, they have an easier time developing for multiple platforms with Java, which reduces costs and shortens development cycles.

Of course, developing Web-based management tools is not completely free of potential drawbacks. For instance, Java is not as cross-platform flexible as it may seem. Storage vendors and systems integrators must be disciplined enough to avoid nonstandard language features and to make sure the software functions similarly on different browsers.

Also, in spite of the hype, Java is still an emerging technology. Java development is challenging. It`s not as well understood as Microsoft Windows programming, and there are fewer experts. And Java development tools aren`t as mature as their Windows counterparts. For example, Java lacks advanced standard interface classes.

However, the trend toward Web-based storage management tools will continue to accelerate. And over time, Java will become the distributed management platform of choice because users will demand the flexibility to run high-quality graphical management tools from any location and any type of system on the network. Since the Web is the ubiquitous distributed environment of the future and Java is the cross- platform development tool of choice, it is natural to apply their benefits to the problem of managing the network`s distributed storage resources.

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There are four approaches to SRM implementation, each with strengths and shortcomings.

David Habermehl is a product planning manager for Digital Equipment Corp.`s storage business unit in Shrewsbury, MA.

This article was originally published on October 01, 1997