EMC on Thursday said it has acquired Berkeley Data Systems, which offers the online backup service Mozy. Financial details were not disclosed.

Berkeley's Mozy is a subscription service used for backing up desktops, laptops, and remote-office servers. The company said it has 300,000 customers, including consumers and small and midsize businesses. The service is available at no charge for storing up to 2 Gbytes of data. Unlimited storage is available for $4.95 a month.

"The acquisition of Mozy is a natural extension of EMC's leadership in the protection and security of personal and business information," Tom Heiser, EMC's senior VP of corporate development and new ventures, said in a statement. "We will continue to invest in Mozy's full portfolio of online backup and recovery services and advance the Mozy brand in the marketplace."

Remote backup services have been gaining ground for individual and small-business users in the last few years, thanks to the proliferation of broadband connectivity and cheap server-side storage. Also, people are a little more comfortable with trusting their data to an online service than they were a few years ago, especially if the data is encrypted on the user's computer and not readable by the provider. Berkeley Data said Mozy's service provides that level of protection.

Mozy's paid service offers unlimited restores. Users can restore files and folders from a browser by right clicking. Consumers can pay monthly or annually; the latter is priced at $54.45. Mozy's rivals include Carbonite, which sells unlimited storage for $49.95 per year.

Mozy also lets users select files and folders to backup. Alternately, users can choose the type of files, such as music tracks or digital photos, for backup. Other features of the service include data-on-DVD ordering, custom scheduling, and automatic Microsoft Outlook backup. Mozy supports Windows and Mac operating systems. The latter version is in beta.

EMC said the transaction wouldn't have a material impact on its revenue or earnings for this year.