CREATING A: Quality-of-Storage-Service Model - Industry Trend or Event

Computer Technology Review, April, 2001 by Robin Purohit

Building an efficient QoSS model that allows data-center managers to deliver on these varying levels of commitment in a complex, heterogeneous storage environment while reducing the total cost of storage requires a change in the approach to managing storage. These changes require careful re-evaluation of how data center staffs are organized, processes used to provision and maintain storage, and exploration of new technology. A recommendation of the major elements of this transition is below:

1. Install small-scale Storage Area Networks (SANs), a new technology to improve connectivity between multiple servers and storage devices, for targeted applications to identify key ROI metrics on those basic installations and help in planning the transition to larger-scale SAN implementations.

2. Reduce risk by defining and implementing best practices for rolling out and managing more scalable enterprise-class SANs, which permit efficiencies because of economies of scale by being able to share the storage infrastructure flexibly across many Storage Accounts.

3. Put Storage Account security methodologies in place to provide assurances that an organization's data cannot be maliciously or accidentally accessed by another set of users.

4. Create a new highly specialized role of Storage Administrator within the data-center team with up-to-date skills in storage technology and clearly defined accountability to meet the defined levels of QoSS, as well as cost and security expectations.

5. Select a standard set of centralized storage management and data availability solutions that enable the implementation of QoSS metrics using the defined best practices in the heterogeneous enterprise class SAN.

6. Assess and deploy emerging Storage Virtualization architectures, which can dramatically simplify the management processes for large amounts of storage by providing logical abstraction of the physical infrastructure and reduce the need to manage the storage or server platforms on a vendor-specific basis.

7. Implement charge-back tools and processes, which allow Storage Administrators to generate reports on costs and delivered service metrics associated with QoSS levels for each Storage Account to ensure accountability and accurate billing.

A QoSS model can provide significant efficiencies in addressing the escalating costs of storage and optimize the impact of highly skilled IT staff. By combining new process, tools, and technology, deploying a QoSS affects the bottom line by:

* Escalating the visibility of the generally hidden storage administrative costs by using a billing or charge-back model for each storage account based on levels of service

* Reducing delays for strategic IT projects due to storage-skills shortages by relying on a specialized storage administrator team with up-to-date storage expertise

* Removing inefficiencies by leveraging the "economies of scale" of centralized procurement and sharing of consolidated server and storage resources

* Enabling flexibility to optimize the storage costs and characteristics to the needs of a specific application or organization, which may change over time, by empowering the storage administrators to configure various levels of service without a high degree of manual reconfiguration.

* Facilitating implementation of high levels of storage service -- e.g., very fast-application time-to recovery or enabling data availability to survive even the catastrophic geographic failures that might otherwise be impossible because of costs or complexity.

Time to Recovery

Time-to-Recovery refers to the rate at which applications can be back online with full access to their data in the event of a network, hardware, or soft application failure. Time-to-Recovery metrics can range from hours, for applications or services such as intranet Web servers not critical to business operation, to seconds for e-commerce or business-to-business applications that directly affect a company's revenue stream. To make the management of application recovery time for many Storage Accounts efficient, the Storage Administrator needs to avoid a high degree of manual and platform-specific operations, such as physical storage or server reconfiguration. Elements of recovery time that must be managed include server and OS recovery, reconnecting the application to its storage, restarting the application, and reconnecting the application to the network.

To measure Time-to-in hours or days, traditional backup and restore strategies can be used in which a copy of the applications data is stored on tape and is restored to the server when a failure occurs. This leaves the task of servering an application restart to other processes or tools. More advanced backup and restore strategies use "tape virtualization" with automated tape libraries or other forms of storage virtualization to implement continuous incremental backups and point-intime data snapshots on tape to minimize the labor and amount of data required to restore the application's data to online disk.