But what really drives cloud computing is end users’ expectation to have access to everything, all of the time, according to Geva Perry, author of the blog Thinking Out Cloud, at the Cloud Connect conference in Santa Clara, Calif., this week.

Consumerization of IT as well as democratization of IT and the trend of “millennial entitlement,” a younger end-user base that expects everything to just work, to be connected and accessible from anywhere, makes the cloud more relevant than ever, Perry said.

“Cloud is on-demand, it’s there, it has low upfront costs and that makes it easy for folks to adopt it.” Perry said. He claims enterprise IT has warmed to cloud as well, as IT pros find ways to make it work by minimizing friction, creating self-service and building and designing products in a way that encourages use.

After cloud makes its way into the enterprise, how can IT teams keep applications running seamlessly while still protecting consumers and end users? Plan, test and prepare for the worst.

Bill Gillis, director of eHealth Technologies at Beth Israel Deaconess in Boston, relies on virtual patching. “Our website [BIDMC.org] is attacked every 10 seconds, 24 hours a day,” said Gillis. And those attacks are only increasing. The health care provider relies on TrendMicro’s Deep Security app to secure its cloud, which includes a network of 1,500 physicians.

And as Beth Israel Deaconess grows to include more physician networks — and it will, as it expects to increase to 500 practices by the end of this year — Gillis plans to run to a mix of public and private clouds as well as virtual desktops to help control end points. “So we will just basically provide a URL to our physicians and it’s full virtualization.”

Don’t fear a cloud failure, prepare for it
The need for cloud managers to prepare was advice echoed all day at the conference. “Complexity always increases. Latency defects accumulate and will cause crazy failures to happen,” said Jesse Robbins, cofounder of Opscode.

Sure, outages happen. Robbins’ advice? Adopt resilience engineering, a practice often used in industries such as aviation, space transportation, health care and manufacturing, in which IT failures could be catastrophic to human life. The first step to do this is to “automate all the things.”

By allowing the cloud to run as automated as possible, IT staff can quickly see where failures will occur. Involve all departments in testing and load balancing. Gone are the days when IT simply threw things over the wall for testing. The DevOps culture is now, and it has its benefits in cloud.

Only after all teams are on board can cloud admins focus on reliability, specifically mean time to fail (MTTF) and not just mean time to recover. Remember, failures will happen eventually. “Automate all the things, test what you do and press the buttons,” Robbins concluded.

What shape will the cloud take? It’s still too early to say for sure, but my gut tells me the cloud will be inextricably linked with Linux-inspired tools, applications and operational philosophies.

Web 2.0 and the cloud set is dominated by mainstays of the Linux ecosystem: programming languages (Ruby and Python), operating system-provisioning tools (Cobbler and Foreman), configuration management and automation frameworks (Puppet and Chef) and monitoring suites (Nagios and Zabbix). Linux folks, who lament Windows’ cost, security and lack of programmability, also dominate the emerging DevOps movement.

In a roundabout way, a new Linux Foundation survey confirms my suspicions: New instances of Linux — and that has to describe anything remotely cloud-like — are overwhelmingly going toward new applications. In the past two years, the survey found, 71.6% of new Linux deployments went to brand new applications and greenfield deployments, versus 38.5% and 34.5% of new Linux instances that were derived from Windows and Unix migrations, respectively. It’s hard to change horses midstream, but less so when you’re still on the riverbank.

What kinds of new workloads are IT shops deploying on Linux? Big data, for one. Organizations that plan to add servers to support big data workloads will use Linux over Windows by a two-to-one margin (71.8% vs. 35.9%). Given big data’s open source and Linux heritage, that’s not entirely surprising, but it’s still quite telling.

Meanwhile, in the short term, the big names in cloud are hedging their bets.

Amazon, for example, recently extended its Amazon Web Services Free Usage Tier to Windows Server 2003 R2, 2008 and 2008 R2, providing developers up to 750 hours of testing time per month, for up to one year. The service was previously limited to Linux Amazon machine images, and it should be a boon to enterprise developers testing multi-tier apps that run on mixed platforms.

But at the same time, Microsoft itself is set to begin offering Linux instances on Azure, making it possible to move existing Linux apps to Redmond’s Platform as a Service (PaaS), rather than building them from scratch. I would have loved to have been a fly in the wall in that meeting.

Of course, Windows still dominates the data center. In the third quarter of 2011, Windows servers represented 49.7% of all factory revenue, compared to 18.6% for Linux servers, according to the IDC Worldwide Quarterly Server Tracker. But Linux server growth outpaced that of Windows by a healthy margin, 12.3% compared to 5.3% for Windows. Linux won’t overtake Windows anytime soon, but with cloud on the horizon, the wind is at its back.