A survey from the Uptime Institute found that while data centers are getting better at managing power than ever before, the rate of failures has also increased \u2014\u00a0and there is a causal relationship.\nThe Global Data Center Survey report from Uptime Institute gathered responses from nearly 900 data center operators and IT practitioners, both from major data center providers and from private, company-owned data centers.\nIt found that the power usage effectiveness (PUE) of data centers has hit an all-time low of 1.58. By way of contrast, the average PUE in 2007 was 2.5, then dropped to 1.98 in 2011, and to 1.65 in the 2013 survey.\n\nPUE is a measure of the power needed to operate and cool a data center. A PUE of 2 means for every watt of power to run the data center, another watt is needed to cool it. A PUE of 1.5 means for every watt into the IT systems, a half of a watt is needed for cooling. So, lowering PUE is something of an obsession among data center operators.\nHowever, Uptime also found a negative trend: The number of infrastructure outages and \u201csevere service degradation\u201d incidents increased to 31 percent of those surveyed, that\u2019s up 6 percentage points over last year\u2019s 25 percent. Over the past three years, nearly half had experienced an outage at their own site or a service provider\u2019s site.\nThis begs the question: Is one causing the other? Is the obsession with lower PUE somehow causing more and bigger outages? Rhonda Ascierto, vice president of research with the Uptime Institute, says no.\n\u201cWe can\u2019t determine that,\u201d she told me. \u201cSome in the media have made that connection, but correlation is not causation. It\u2019s certainly possible they are linked and some findings around efficiency are related, but we did not link those together.\u201d\nMost downtime incidents lasted one to four hours. Uptime asked people who suffered an outage what they estimated the cost to be, but 43 percent didn\u2019t calculate the cost of an outage. That\u2019s because far too many factors in determining the cause were outside that person\u2019s specialty. Half of those who did make an estimate put the cost were less than $100,000, but 3 percent said costs were over $10 million.\nWhat causes data center outages?\nThe leading causes of data center outages are power outages (33 percent), network failures (30 percent), IT staff or software errors (28 percent), on-premises non-power failure (12 percent), and third-party service provider outages (31 percent).\nTo err is human, and this survey showed it. Nearly 80 percent said their most recent outage could have been prevented. And that human error extends to management decisions, Ascierto said.\n\u201cOftentimes, people talk about human error being the cause of outages, but it can include management errors, like poorly maintained or derated equipment that may not match runtime requirements,\u201d she said. \u201cThe human error comes down to management responsibility.\u201d\nShe added that another cause of failures is there is a trend toward data center consolidation, with firms moving workloads from secondary data centers to primary ones. This takes time, and since the secondary is being decommissioned, the owner doesn\u2019t invest in it. So wear and neglect creeps into a doomed data center, making it more likely to fail.\nAnother cause for problems is the cascading effect of one data center taking down others. That could be either two private data centers or a hybrid situation where an on-premises center is connected to a third-party provider such as Amazon or Microsoft. If one goes down, it has a greater chance of taking down the other(s).\nUptime found 24 percent of those surveyed said they were impacted by outages across multiple data centers. \u201cFive years ago it would be a much lower number,\u201d said Ascierto, who added she expects an increase in outages caused by cascading failures between multiple sites, since more and more companies are adopting multiple cloud services strategies, as well as the growing interdependency of multiple IT services.\n\u201cThere is this belief that having a hybrid architecture makes you more resilient, but visibility and accountability is more difficult and the rate of outage is high,\u201d she said.