More than half of businesses in a recent survey say they are considering offloading some of their storage needs to cloud providers, despite concerns about security.

Growing data volumes are the key driver for organisations considering cloud storage, followed by limits on current storage capacity, the large footprints of data centres, lengthy data retention requirements and the cost of storage infrastructure, the survey found.

The survey was conducted by backup vendor CommVault and involved its own customers, so results may not be representative of the IT industry as a whole. CommVault surveyed 535 companies, about half of which have more than 1,000 employees, and nearly 60 percent of which manage between 6TB and 75TB of data.

Fifty-two percent of respondents are considering cloud storage services now or in the future, but have not necessarily made the plunge into the cloud yet.

Customers said cloud storage could help with disaster recovery, replace old tape drives, reduce hardware expenses and introduce more flexible pricing models. But even those who are interested in the cloud have concerns. More than 75 percent of the survey sample said they have some concerns about moving data to a storage cloud, with 30 percent saying security is their biggest worry. One out of five customers said reliability is the biggest roadblock.

Recent outages by cloud service providers such as Rackspace and Amazon probably aren't instilling confidence in customers, and the cyberattack on Google has also spurred debate over the safety of cloud computing.

IT pros who attended the Storage Networking World conference last October said they worry about security, legal issues and the portability of data, and that cloud services aren't yet mature enough to handle some types of sensitive information.