The Big Backup Squeeze

A survey says backup duties are a time sink, yet fast access to stored data is crucial. Is disk-to-disk the answer?

Fed up with slow tape backup systems and under pressure by regulators and auditors to keep data online and readily available, large and midsize businesses are making disk-to-disk backup technology a top priority in their data centers this year.

More than 75% of 150 large companies surveyed by TheInfoPro Inc., a New York-based independent research firm, said disk-to-disk backup technology is being used in their data centers, compared with 67% that were implementing it a year ago.

Still, in this latest survey, conducted in May, only about one-third of the respondents said they use virtual tape libraries, a form of disk-to-disk backup that uses disk arrays to mimic tape for server backup jobs.

File It Right

One in four IT managers surveyed said they believe poor archiving practices are a key reason for unchecked data growth. The average company has 250TB of active storage space dedicated to archive-related content. Moreover, the survey found that archive capacity among companies is expected to grow by 52% by years end.

Sean OMahoney is manager of client/server computing at Norton Healthcare Inc., the largest health care system in Kentucky, with more than 2,000 physicians. He rolled out three disk-to-disk backup systems over the past year to help the Louisville-based organization deal with a 50% year-over-year archival data growth rate that pushed the backup window to 20 hours per day.

Since connecting its Picture Archiving and Communications System to an EMC Clariion Disk Library 710 array and Clariion Disk Library 4100 array, Norton has cut its backup window by more than half to eight hours per day. OMahoney says he also plugged the companys financial systems into an EMC Centera disk array, which is a WORM permanent archive system.

In all, Norton Healthcare has 200TB of capacity dedicated to disk-to-disk backup, the vast majority of which is used for storing radiological images such as X-rays, which do not lend themselves easily to compression.

Besides shrinking its backup window with disk-to-disk technology, the organization also improved data restore times by as much as 75%. It used to take four days to retrieve data from tape because Nortons AIT-2 tape drives have a maximum throughput of 6MB/sec., compared with the Clariion disk arrays 60MB/sec. rate. The speed of the media is vital, OMahoney says.

Squeezed by Time and Budgets

TheInfoPros latest survey revealed that IT managers consider backup activities among the most time-consuming. It also found that staffing remains flat and budgetary pressure to cut costs is at an all-time high.

A study by Gartner Inc. earlier this year predicted that by 2010, disk not tape will be the primary medium for data recovery. It also predicted that by 2011, the ability to take continuous snapshots of data will be an embedded function in backup and data replication software and will no longer be a separate feature. Currently, only 17% of companies have deployed continuous data protection, according to TheInfoPros survey.

The need for high- performance online recovery of data, combined with the availability of low-cost disk arrays, has influenced enterprises and small and midsize businesses to adopt a disk-based approach for backup and recovery, wrote Dave Russell, author of Gartners disk-based storage report.

Tony Asaro, an analyst at Enterprise Strategy Group Inc. in Milford, Mass., says the driving force behind the disk-to-disk backup boom is a combination of massive data growth, which is expanding backup windows, and legal and auditing requirements that force firms to keep records online and accessible for longer periods.

Everyone we know is doing some sort of disk-to-disk backup, Asaro says.

Most companies, however, are still relying heavily on tape backup for archive, keeping data on disk for 120 days or less, Asaro says.

OMahoney says he typically keeps data on his disk-to-disk backup systems for about three weeks. His companys auditors, however, recommend that he keep that data on disk for at least five weeks, something OMahoney is now planning to do.

Also, after seeing some proofs of concept that apply to his companys infrastructure, OMahoney says his disk-to-disk systems will benefit somewhat from emerging de-duplication technology, which he hopes to roll out over the next year. De-duplication ensures that only a single instance of structured or unstructured data is copied during backup. In many cases, the vendors claim, de-duplication can reduce capacity needs by as much as 80% on more costly disk-based subsystems.

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Copyright © 2007 IDG Communications, Inc.

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