While the new centre would not create any new jobs, it would make existing jobs more secure, he said in an interview.
''We wouldn't be investing in the region if we were not serious about staying here.''
Gen-i, part of Telecom, was committed to ongoing investment in the things that made a difference to its clients, Mr Mills said.
With the opening of the new Christchurch data centre earlier this week, Gen-i now operated a combined network of 15 Gen-i data centres and five Revera Homeland data centres across New Zealand.
It had also invested in additional capacity in Auckland and Wellington.
''This is the largest, most comprehensive network of highly resilient facilities in New Zealand,'' he said.
Gen-i southern regional manager Peter Thomas said he had a strong base of clients who were looking for more support, particularly with ''cloud'' options.
When people talked about the cloud, or the hosting of data off site, they often thought about large overseas companies, like Google.
However, New Zealand companies wanted to buy cloud storage as part of an overall scheme and often preferred a New Zealand company hosting their data.
The move to a local data centre was viewed as a first step in a pathway to cloud hosting.
''They like to walk past where it is stored by us and they want their data to stay in New Zealand.''
The new Dunedin data centre would be located at the hub of the Telecom CBD network.
Both facilities shared the resilient infrastructure required to ensure service continuity to all Telecom services, such as the public telephone network, Mr Thomas said.
Continuity of power supply and back-up generation was a civil priority in the ''substantial and highly secure'' public infrastructure location.
Asked about security of data, Mr Mills said data security was important to everyone. There could be reasons for New Zealanders wanting to have their data stored in another city or overseas.
''With the recent seismic activity in New Zealand, clients have become more interested in the prospect of data recovery. We ... can offer world-class security.
''Decreasing costs of bandwidth, coupled with the realisation from recent natural events of the real need to have robust back-up makes other-city and other-island disaster recovery facilities a real option, if not a necessity.''
Dunedin offered a secure location for businesses further afield to house back-up solutions, Mr Mills said.
