While tech companies are trying to outdo each other in data centre design and energy efficiency, small businesses still can find choosing a data centre a tough proposition. Entrusting your company's data and valuable information to someone else needs additional research and a certain confidence level with customer service.

A business may need a data centre to continue its growth, but there are a few things to know before signing a contract. Whether it's about security, emergency plans, or cost, here are few questions to ask.

1. How secure is your physical site?

The answer to this open ended question could be as long as a white paper or a SANS Institute data centre checklist. Physical security is essential for data centres and is the first line of defence. Each data centre should be a standalone building with at least a 20-foot, fenced perimeter and a secure, cool core of servers. It should be located a distance from your office and monitored by cameras and guards who require photograph IDs at two security checkpoints.

All employees should be cross-trained so they can handle a disaster situation immediately if one occurs. The data centre should have an emergency plan in place that requires back-up generators, off-site backups of essential information, and servers at another data centre than can be switched over. To prevent downtime in case of an outage, make sure the data centre receives electricity from at least two separate utility substations.

2. What's your virtual machine to physical host ratio?

One of the ways to keep costs down is a higher virtual machine to physical host ratio. There needs to be a four-to-one ratio to break even on server costs, but most servers can easily handle more than a dozen. Using efficient virtualisation will cut down on expenses on servers, electricity, and space - saving your business money.

3. What are you doing for energy efficiency?

What you want to hear is that the data centre manager is always looking for ways to increase productivity and lower energy costs. You also want to know the data centre will be open to new ideas from you or industry analysts. Both eBay and Facebook saved money at their data centres by working with local utilities and implementing their own ideas to make their cooling systems more efficient. Granted, both eBay and Facebook probably have more clout than a small business, but your data centre should be listening to all of its customers.

Also, data centres should have the latest, energy-efficient versions of your servers, which can cut energy costs by as much as 40 percent.

4. How does your cooling system work?

Data centres should host servers in room with a core temperature of between 68 and 75 degrees Fahrenheit. Cooling is usually about half the cost of operating a data centre. But facilities often kept temperatures too low, thinking it was better to be safe than sorry. Contemporary data centres should have IT integrated with the building's cooling system and use remote control temperature monitoring and sensors to keep temperatures safe and costs down.

5. What is your disaster recovery plan?

Although you probably never want to have it happen, your data centre should have a disaster recovery plan in place to make you and your business feel safe. In 2007, 365 Main's San Francisco data centre suffered a power outage that affected 40 percent of its customers, a veritable who's who of Bay Area technology.

According to the company, 365 Main's 10 back-up diesel generators should have immediately started--the company needed eight to power the centre - but three didn't start because of what was later deemed to be a faulty electronic controller. The data centre was down for approximately 45 minutes, and taught companies to find out how a data centre plans to notify customers in an immediate emergency, keeping them apprised of latest developments and the status of their company data or services.

If you ask most of these questions, there will be few surprises in an emergency or a security breach. Like any business offering services, it's up to the customer to do research and find a reputable company, but entrusting another business with your data and information needs an additional layer of investigation. Don't be afraid to ask the hard questions - and if the data centre representatives sound offended or defensive, you probably need to shop around.