Disk arrays gain in use for secondary storage

Relatively inexpensive secondary disk storage is gaining a significant foothold in corporate data centres, according to a survey of more than 1000 IT managers that's due to be released next month. But the survey also shows that a large majority of data is still backed up and archived the traditional way: on tape.

Peripheral Concepts, which released preliminary results of the survey this week, said about 50 per cent of the respondents with disk storage capacities of more than 500TB indicated that they already use disk-based devices for secondary storage.

That included saving snapshot copies of data and staging information for archiving, the consulting firm said. Another 25 per cent plan to start doing so within two years.

But secondary disk storage typically involved less than one-fifth of a company's total data, president and CEO of Peripheral Concepts, Farid Neema, said.

And only a small percentage of the data that was backed up on disks did not get moved to tape devices for archiving, Neema said.

"Tape remains by far the most popular medium and does not seem to want to go away," he said.

Neema cited another potential roadblock to wider adoption of secondary disk storage: a "significant percentage" of the respondents indicated that reliability issues could prevent them from using low-cost Advanced Technology Attachment (ATA) disk drives.

Over the past 12 months, vendors such as EMC, Network Appliance and Storage Technology have released ATA-based disk arrays for storage of near-line data, snapshot copies and information that will eventually be archived on tape devices.