Disaster recovery system ensures 100% uptime - Trends

Communications News, Jan, 2002 by Ken Anderberg, Carren Bersch, Sean Kelly, Ray Peckham

When the Los Angeles Department of Water and Power (DWP), the largest municipally owned utility in the nation, decided to replace its existing disaster-recovery (DR) system, it chose a solution that mirrors, electronically, disaster recovery data to a remote site--instead of physically shipping tapes. The implementation also mirrors the growth in the U.S. of enterprise storage systems.

According to Forrester Research, corporate storage capacity is growing at 52% a year; Gartner research analysts predict enterprise storage capacity will double every year in the near term, either within enterprise LANs or through managed storage providers. Networked storage, therefore, will take on a critical role for enterprises needing more storage capacity.

The L.A. DWP is no exception. DWP is responsible for serving 3.8 million people and businesses in a 464-square-mile area. The department's mainframe contains application data necessary for payroll services, accounts payable and customer service. With its new mirroring solution, production processing can be shifted to the data recovery site in less than an hour, ensuring business continuity for the department.

The system uses the UltraNet Storage Director from CNT (www.cnt.com), Minneapolis, and IBM's (www. ibm.com) TotalStorage Peer-to-Peer Virtual Tape Server. For DWP, the system improves data integrity, increases system efficiency and decreases employee time spent on maintaining backup tapes. In the event of a natural disaster, such as an earthquake, the applications can be easily recovered online.

The system includes two mainframe hosts (one for each site), four CNT storage devices, two ESCON directors, two Model B18 IBM tape servers and four AXO Virtual Tape Controller units. The two sites are connected using four DS3 links, while ESCON is used between the storage and tape servers.

Prior to the new disaster-recovery solution, employee and customer data that drove applications was only available through the backup tapes. Whenever DWP needed to restore data to the system mainframe, thousands of backup tapes were shipped from its remote site. When this system was tested, restoration issues developed due to the shipping time required, and because tapes could be lost during shipping. The new solution ensures all data on the mainframe is replicated to the remote site in real time, through a bidirectional mirroring environment.

"This is an ideal disaster-recovery solution," says Dennis Thun, manager of operations for the department. "Previously, it took us many hours of data recovery from tape, prior to even restarting our system, and then two to three days to accomplish the DR testing. With our new system, it takes two hours to bring the system and online applications up, and we have all the tape data accessible immediately."

The department's decision to implement a disaster-recovery solution resulted in numerous business benefits, including less time devoted to maintaining backup tapes and the added assurance that customer data would be accessible and secure, in any situation, at any time.

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