Database and storage management: new storage-management products reduce administration and accelerate transactions. (Storage Networking).

The successful operation of an enterprise database depends on more than just the robustness of the software and the intuition and skill of database administrators (DBAs). Table structures, software design, processor speed and reliability play a large role in delivering continuous, high-speed database behavior, but the underlying storage performance, storage bandwidth and storage management practices have equal importance. Functional managers depend on DBAs to keep their systems running, but often underestimate the amount of time spent on storage-related activities to support the database.

Many DBAs spend much of their day configuring, allocating, requesting, monitoring, tuning, moving and updating storage to support their base disk requirements. It's a tedious collaborative effort involving several members of the IT staff. Given the choice, most line-of-business managers would rather have their DBAs concentrate on data quality, analysis and other service-level considerations instead of around-the-clock disk management.

Physical disk limitations and operating system shortcomings are to blame. Whether it's a simple JBOD directly attached to a server, or a storage area network using the latest intelligent storage subsystems, balancing 110 bandwidth, reliability and response times requires undue attention. The wrong decisions could not only jeopardize the performance and productivity of the databases, but also the availability of the data. To date, hardware constraints have put the DBA in a precarious position, with few tools to succeed.

Fortunately, a recent emergence of management products with automated features, like DataCore's SANsymphony, are helping to alleviate the storage burden, enabling application owners and DBAs to concentrate on the "business end" of their information. The most comprehensive of the new storage management offerings come as independent network nodes (not embedded in storage hardware or loaded on application servers), with a range of consolidated features that span multiple servers and storage devices.

There are five significant attributes of storage from the database perspective; the latest software addresses all of these needs:

* Performance

* Availability

* Scalability

* Disaster Recovery

* Upgrades

Boosting Database Performance

Productivity and profitability depend on performance, so the pressure is on to deliver the best at the lowest cost. Achieving high transaction rates is made difficult by the current disparity between server and storage performance. Server processors, memory and bandwidth are getting faster and cheaper. Disks are getting bigger and cheaper--but as a result of the capacity crammed on each spindle, they are effectively getting slower. The number of I/Os per gigabytes of disk space has steadily dropped over the past six years.

So what happens? One of the workarounds commonly practiced (and advocated by database vendors) is to distribute data tables and reference files across many smaller, dedicated disks. Such "striping" increases 110 parallelism and shortens access times. With it comes drastically underutilized capacity; spindles often going more than 70% unoccupied. The other problem is that no matter whether the storage is direct-attached or networked, the administrators must manage direct relationships between each table and a specific physical disk, greatly increasing the management complexity.

One successful approach to improving performance is the use of storage network management devices that add a layer of cache in front of storage. One major storage and systems supplier tested methods of improving performance in various database environments. They used DataCore's storage network management software that provided performance-boosting cache as well as storage virtualization and automation. In their preliminary tests, they achieved 85% improvement in data access performance from just a single instance of the software. Even database updates benefited by 15%.

Community Health Network of Indiana is demonstrating similar database performance gains in a production environment, with similar hardware and the same storage management software. In its case, with multiple nodes providing additional cache, it is actually experiencing a 300% improvement in database operations. Rick Copple, CTO at Community, said, "The improvement in performance is so dramatic that our doctors noticed it immediately."

Keep Databases Churning

The value of non-stop access to data cannot be underestimated. Here are some common industry statistics that reinforce how costly downtime can be:

DBAs and storage administrators work hard to minimize the impact of unexpected failures, using clustered servers, redundant paths through redundant switches to RAID arrays on the backend. However, some sources of downtime are overlooked, such as planned downtime for storage maintenance and capacity re-allocation. In a study of ecommerce websites, Aberdeen Group estimated that about 30% of all user-perceived Web server outages are caused by planned storage reconfiguration.

Currently, RAID storage is a widely used means of protecting data at the storage level. With the data redundantly distributed across multiple disks, the enterprise is protected against the malfunction of one of the drives. If the array fails, however, there's potential for big trouble.

Rather than relying on a single RAID device for backend database protection, a better choice is to distribute the redundant copies of data across completely separate disk arrays, on separate power sources, perhaps even separate floors or buildings. Storage hardware with this capability tends to be cost-prohibitive to many who need it.

That was the case with Mark Moroses, senior director of technical services at Maimonides Medical Center in N.Y., one of the country's largest teaching hospitals. "We looked at the typical assortment of high-end arrays from major vendors. But we couldn't find the right combination of features and price that met our needs and budget."

There are also server-installed software and hardware products that can mirror every database update across two different storage devices. However, maintaining components on each server adds to the workload and uses server resources to create the redundant copies.

As a result, organizations like Maimonides are selecting network-level management products that offload mirroring from servers, while maintaining the ability to replicate valuable data across disparate, lower-cost hardware. In fact, Maimonides was recently given a prestigious industry award for "industry-best storage reliability." According to Moroses, "the feature set was right, including support for a wide range of disk devices. This enabled us to buy some quality mid-range disk without sacrificing remote mirroring, high availability options, etc."

Automatically Accommodate Growth

Another headache for database managers and users is the downtime--and related stress--caused by disk space shortages. Administrators must search each server for free disks, incur downtime to remove and then re-install those disks, re-cable and re-configure volumes. This situation is so painful that database owners request an excess of storage to postpone the event, and in turn, the storage buyer incurs added expense. This chain reaction of over-provisioning makes it easy to see why industry analysts estimate that up to 70% of storage capacity is wasted.

Conseco Finance, one of the largest consumer finance companies in the nation, is very familiar with this type of capacity reallocation problem. Under good conditions, moving storage took four hours. In more complex scenarios, up to four days of planning and configuring might be required. An estimated 40% of application owners' time, plus labor from dedicated storage administrators, was spent dealing with these issues.

To help firms like Conseco Finance, storage suppliers and software developers are either delivering or planning automated provisioning functionality. Ideally, the feature provides database applications with just the right amount of storage at exactly the time that it is needed.

Traditionally, volume management tools are employed for the ability to grow volumes. While workable, the routine needs to be manually done on a server-by-server basis. There are options from some storage software vendors that use a software agent on the database server to allow a separate management device to centrally allocate more storage when needed. However, the effectiveness of this feature is limited to the select operating systems supported.

This past year, Conseco Finance deployed a storage networking software solution that "literally takes storage concerns Out of the equation for those edge administrators, centralizes it at a pool level and automates the provisioning of more storage," according to Rod Lucero, chief architect.

The software is capable of making the application believe it has a tremendous two terabytes volume at its disposal, without the immediate need to have all that disk capacity in-house. As the database consumes capacity, the software allocates small portions of physical capacity to meet the demand. Servers never experience downtime as a result of moving or adding storage, and the disk capacity is very efficiently utilized. This type of advanced automation defines the new era of best practices for database and storage administration.

Affordable Disaster Recovery

Enterprises need to protect databases and ensure fast recovery, but at a reasonable cost. As a result, the high annual charges of storing tapes offsite and hot/cold site leasing are strategies that are being scrutinized.

There are a few approaches to maintaining redundant databases remotely. There are server-installed components that replicate database volumes over long distances. These have the benefit of being able to mix and match different makes and models of storage at the primary and contingency sites. There is a notable tax paid in terms of database performance and administration of each and every server with this approach, as application processing competes with data replication overhead.

Storage hardware vendors also offer a remote replication capability as an add-on feature for their higher-end offerings. However, as Scott Hoffman, IT director of Burnett Companies Consolidated in Texas discovered, 'To protect our data by replicating to a remote site [using his current supplier's product] would have required purchasing a second, equally expensive high-end array just for contingency purposes. Plus, we had to add unique protocol translation hardware and special communications infrastructure to connect the two sites." Hoffman concluded, "We simply couldn't afford to go that route."

As a result, many enterprises like Burnett are implementing storage networking software that consolidates replication functions for all servers and storage, allows for total flexibility in types and grades of storage at either end (e.g., high-end storage at the primary and less-costly disk at the contingency site) and uses economical Internet connections to transfer data. With this lower-cost structure, more databases can be fully protected.

Expedient Upgrades

Database owners, managers and users continually cope with the ongoing series of software and hardware upgrades that disrupt business. Administrators must generate a sample database for upgrade testing, recreate the operating environment of the production server, and then apply the upgrades. This procedure, as well as the new environment, is tested thoroughly. After the upgrade is approved, administrators must take the production servers offline during odd hours, reproduce the exact series of steps for each server and hope that the database returns to operation without any unexpected consequences. In large enterprises with many application servers, this is a tedious, labor-intensive and risky process.

When centralizing and deploying 135 financial database servers, the maintenance implications were apparent to Conseco Finance. They simplified the process with extensive use of snapshotting.

First, the IT staff configured a model server. Scripting triggers the snapshot feature to automatically generate 134 more copies of the same basic setup, which are then quickly and non-disruptively allocated. In the case of an upgrade, they simply configure one server to the new specifications, then use the same routine to deploy the upgrade.

"Setting up all these servers with all the right software components would have been a time-consuming and painful process had it not been for [the] snapshot feature... As we maintain and update these systems going forward, the snapshot feature will be an integral part of deployment," according to Lucero.

Get Back to Business

Business-line managers who depend on database operations can improve productivity and reliability by taking advantage of modem storage networking functionality. Some common database practices developed for expediency's sake to compensate for the shortcomings of storage devices can now be improved by more flexible, centralized storage-network-management-software capabilities. In turn, those with financial responsibility for operations benefit from increased efficiencies, utilization and performance. As an added advantage, both DBAs and storage administrators can rid themselves of tedious back-end storage concerns and focus more attention on other critical operations.

Industry        Database Application  Avg. Cost/Hour of Downtime

Transportation  Airline reservations          $   89,500
Retail             Catalog sales              $   90,000
Retail            Home TV shopping            $  113,000
Media               Pay-per-view              $1,150,000
Financial        Credit card sales            $2,600,000
Financial       Brokerage operations          $6,500,000

Calvin Hsu is product marketing manager at DataCore Software (Ft. Lauderdale, Fla.)

www.datacore.com