"To moderate appetites": Several ways to improve the energy efficiency of data centers
To ensure the efficient operation of data centers today consumes a lot of electricity. In 2013, only US data centers consumed about 91 billion kilowatt-hours of energy, which equals the annual output of 34 large coal-fired power plants.
Electricity remains one of the main items of expenditure of companies-owners of data centers, because they are trying to improve the efficiency of the computing infrastructure. For this purpose, various technical solutions are used, some of which we will talk about today.
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/ photo Torkild Retvedt CC
When it comes to improving energy efficiency, virtualization has several indisputable advantages. First, the consolidation of existing services on a smaller number of hardware servers allows you to save on hardware "iron", which means lower costs for cooling, electricity and space. Secondly, virtualization allows you to optimize the use of hardware resources and flexibly redistribute virtual power right in the process.
NRDC and Anthesis have conducted a joint study and found that by replacing the 3,100 servers with 150 virtual hosts, it is possible to reduce energy costs by $ 2.1 million per year. The organization, which was the object of interest, saved on maintenance and purchase of equipment, reduced the staff of system administrators, received a guarantee of data recovery in case of any problems, and got rid of the need to build another data center.
According to the Gartner study , in 2016 the level of virtualization of many companies will exceed 75%, and the market itself will be estimated at $ 5.6 billion. However, there are certain factors that hinder the widespread spread of virtualization. One of the main reasons remains the complexity of the “restructuring” of data centers for a new work model, since the costs of this often exceed the potential benefits.
Such systems can improve the energy efficiency of a cooling system or reduce the energy consumption of IT equipment, which ultimately leads to cost minimization. In this case, special software is used , which monitors the activity of servers, power consumption and cost, automatically redistributing the load and even turning off equipment.
One of the types of software for energy management is the data center infrastructure management systems (DCIM), which are used to monitor, analyze and predict the energy efficiency indicators of various equipment. Most DCIM tools do not apply to direct monitoring of the energy consumption of IT and other equipment, but many systems have PUE calculators (Power usage performance). According to Intel and Dell DCIM, these solutions are used by 53% of IT managers.
Today, much of the hardware is already focused on economical energy consumption, but during the purchase of "iron" often more attention is paid to the original price or performance, rather than the total cost of ownership, which is why energy-efficient equipment goes unnoticed . In addition to reducing electricity bills, such equipment also reduces the amount of CO2 emissions into the atmosphere.
There are less obvious approaches to improving the energy efficiency of data centers, for example, reducing the amount of stored data. Compression of rarely used data can save up to 30% of energy, even taking into account the fact that resources are also spent on compression and unpacking. Data deduplication can show an even more attractive result - 40–50%. It should be noted that the use of low-power storage for “cold” data also helps reduce power consumption.
One of the problems leading to the inefficient use of electricity in data centers is idle equipment. Experts believe that some companies cannot realistically assess the required amount of resources, while others buy server capacity with the expectation of the future. As a result, almost 30% of servers are out of work, while consuming energy for $ 30 billion per year.
In this case, according to the study, IT managers can not identify from 15 to 30% of the installed servers, but do not write off the equipment, for fear of possible consequences. Only 14% of respondents kept records of unused servers and knew their approximate number.
One solution to this problem is to use public clouds with the pay-as-you-go payment model, when the company only pays for the actual capacity used. According to this scheme, many companies are already working, and the owner of the Aligned Energy data center in Plano, Texas, claims that it allows customers to save from 30 to 50% per year.
The energy efficiency of the data center is affected by the microclimate of the room where the equipment is located. For efficient operation of cooling systems, it is necessary to minimize the loss of cold, isolating the data center's premises from environmental influences and preventing heat transfer through the walls, ceiling and floor. A great way is a vapor barrier, which also regulates the level of humidity in the room.
Too high humidity can lead to various errors in equipment operation, increased wear and corrosion, and too low - to the occurrence of electrostatic discharges. ASHRAE determines the optimal level of relative humidity for the data center in the range from 40 to 55%.
Efficient air distribution can also save 20–25% of electricity consumed. This will help the proper placement of equipment racks: the division of data center machine rooms into “cold” and “hot” corridors. At the same time, it is necessary to ensure isolation of the corridors: install perforated plates in the required places and use blank panels between the rows of servers to prevent air flow mixing.
It is also worth considering not only the location of the equipment, but also the location of the climate system. When dividing a hall into “cold” and “hot” corridors, air conditioners should be installed perpendicular to hot air streams in order to prevent the latter from entering the corridor with cold air.
An equally important aspect of effective temperature management in the data center is the location of wires that can impede the movement of air flow, reducing static pressure and reducing the cooling efficiency of IT equipment. To correct the situation will allow the movement of cable trays from under the raised floor closer to the ceiling.
A great alternative to special climate control systems is natural cooling, which can be used during cold seasons. Today, technology makes it possible to switch to the use of an economizer when the weather permits. According to a study by Battelle Laboratories, natural cooling reduces energy costs for data centers by 13%.
There are two types of economizers: those that use only dry air, and those that use additional irrigation with insufficient air cooling. Some systems can combine different types of economizers to form multi-level cooling systems.
But air cooling systems are often ineffective due to the mixing of airflows or the inability to use the excess heat that has been removed. In addition, the installation of such systems often entail additional costs for air filters and ongoing monitoring.
Many experts believe that liquid cooling copes better with its task. A representative of the Danish vendor Asetek, specializing in the creation of liquid cooling servers, John Hamill, is confident that the liquid is about 4 thousand times more efficient in terms of storage and heat transfer than air. And during the experiment conducted by the Lawrence Berkeley National Laboratory in collaboration with the American Power Conversion Corporation and the Silicon Valley Leadership Group, it was proved that due to the use of liquid cooling and water supply from the cooling tower, in some cases, power savings reached 50%.
Today, there are three areas, the development of which will help make the work of data centers more efficient: the use of multi-core processors, embedded cooling systems and cooling at the chip level.
Computer manufacturers are confident that multi-core processors, completing more tasks in a short period, will reduce server power consumption by 40%. An example of the effectiveness of an integrated cooling system is the CoolFrame solution from Egenera and Emerson Network Power. It takes the hot air coming out of the servers, cools it and “throws” it into the room, thereby reducing the load on the main system by 23%.
As regards the cooling technology of the microcircuits, it allows the heat to be removed directly from the server’s hot spots, such as central processing units, graphic processing units and memory modules, to the surrounding air of the rack or outside the machine room.
Increasing energy efficiency today has become a real trend, which is not surprising, given the consumption of data centers: 25–40% of all operating expenses are accounted for by paying electricity bills. But the main problem is that every kilowatt-hour consumed by IT equipment is converted into heat, which is then removed with the help of cooling equipment that requires a lot of energy. Therefore, in the coming years, reducing the energy consumption of data centers will not cease to be relevant - there will be new ways to improve the energy efficiency of the data center.
Other materials from our blog on Habré:
Electricity remains one of the main items of expenditure of companies-owners of data centers, because they are trying to improve the efficiency of the computing infrastructure. For this purpose, various technical solutions are used, some of which we will talk about today.
')
/ photo Torkild Retvedt CC
Virtualization
When it comes to improving energy efficiency, virtualization has several indisputable advantages. First, the consolidation of existing services on a smaller number of hardware servers allows you to save on hardware "iron", which means lower costs for cooling, electricity and space. Secondly, virtualization allows you to optimize the use of hardware resources and flexibly redistribute virtual power right in the process.
NRDC and Anthesis have conducted a joint study and found that by replacing the 3,100 servers with 150 virtual hosts, it is possible to reduce energy costs by $ 2.1 million per year. The organization, which was the object of interest, saved on maintenance and purchase of equipment, reduced the staff of system administrators, received a guarantee of data recovery in case of any problems, and got rid of the need to build another data center.
According to the Gartner study , in 2016 the level of virtualization of many companies will exceed 75%, and the market itself will be estimated at $ 5.6 billion. However, there are certain factors that hinder the widespread spread of virtualization. One of the main reasons remains the complexity of the “restructuring” of data centers for a new work model, since the costs of this often exceed the potential benefits.
Energy Management Systems
Such systems can improve the energy efficiency of a cooling system or reduce the energy consumption of IT equipment, which ultimately leads to cost minimization. In this case, special software is used , which monitors the activity of servers, power consumption and cost, automatically redistributing the load and even turning off equipment.
One of the types of software for energy management is the data center infrastructure management systems (DCIM), which are used to monitor, analyze and predict the energy efficiency indicators of various equipment. Most DCIM tools do not apply to direct monitoring of the energy consumption of IT and other equipment, but many systems have PUE calculators (Power usage performance). According to Intel and Dell DCIM, these solutions are used by 53% of IT managers.
Today, much of the hardware is already focused on economical energy consumption, but during the purchase of "iron" often more attention is paid to the original price or performance, rather than the total cost of ownership, which is why energy-efficient equipment goes unnoticed . In addition to reducing electricity bills, such equipment also reduces the amount of CO2 emissions into the atmosphere.
Data compression
There are less obvious approaches to improving the energy efficiency of data centers, for example, reducing the amount of stored data. Compression of rarely used data can save up to 30% of energy, even taking into account the fact that resources are also spent on compression and unpacking. Data deduplication can show an even more attractive result - 40–50%. It should be noted that the use of low-power storage for “cold” data also helps reduce power consumption.
Disable "zombie servers"
One of the problems leading to the inefficient use of electricity in data centers is idle equipment. Experts believe that some companies cannot realistically assess the required amount of resources, while others buy server capacity with the expectation of the future. As a result, almost 30% of servers are out of work, while consuming energy for $ 30 billion per year.
In this case, according to the study, IT managers can not identify from 15 to 30% of the installed servers, but do not write off the equipment, for fear of possible consequences. Only 14% of respondents kept records of unused servers and knew their approximate number.
One solution to this problem is to use public clouds with the pay-as-you-go payment model, when the company only pays for the actual capacity used. According to this scheme, many companies are already working, and the owner of the Aligned Energy data center in Plano, Texas, claims that it allows customers to save from 30 to 50% per year.
Data center microclimate control
The energy efficiency of the data center is affected by the microclimate of the room where the equipment is located. For efficient operation of cooling systems, it is necessary to minimize the loss of cold, isolating the data center's premises from environmental influences and preventing heat transfer through the walls, ceiling and floor. A great way is a vapor barrier, which also regulates the level of humidity in the room.
Too high humidity can lead to various errors in equipment operation, increased wear and corrosion, and too low - to the occurrence of electrostatic discharges. ASHRAE determines the optimal level of relative humidity for the data center in the range from 40 to 55%.
Efficient air distribution can also save 20–25% of electricity consumed. This will help the proper placement of equipment racks: the division of data center machine rooms into “cold” and “hot” corridors. At the same time, it is necessary to ensure isolation of the corridors: install perforated plates in the required places and use blank panels between the rows of servers to prevent air flow mixing.
It is also worth considering not only the location of the equipment, but also the location of the climate system. When dividing a hall into “cold” and “hot” corridors, air conditioners should be installed perpendicular to hot air streams in order to prevent the latter from entering the corridor with cold air.
An equally important aspect of effective temperature management in the data center is the location of wires that can impede the movement of air flow, reducing static pressure and reducing the cooling efficiency of IT equipment. To correct the situation will allow the movement of cable trays from under the raised floor closer to the ceiling.
Natural and liquid cooling
A great alternative to special climate control systems is natural cooling, which can be used during cold seasons. Today, technology makes it possible to switch to the use of an economizer when the weather permits. According to a study by Battelle Laboratories, natural cooling reduces energy costs for data centers by 13%.
There are two types of economizers: those that use only dry air, and those that use additional irrigation with insufficient air cooling. Some systems can combine different types of economizers to form multi-level cooling systems.
But air cooling systems are often ineffective due to the mixing of airflows or the inability to use the excess heat that has been removed. In addition, the installation of such systems often entail additional costs for air filters and ongoing monitoring.
Many experts believe that liquid cooling copes better with its task. A representative of the Danish vendor Asetek, specializing in the creation of liquid cooling servers, John Hamill, is confident that the liquid is about 4 thousand times more efficient in terms of storage and heat transfer than air. And during the experiment conducted by the Lawrence Berkeley National Laboratory in collaboration with the American Power Conversion Corporation and the Silicon Valley Leadership Group, it was proved that due to the use of liquid cooling and water supply from the cooling tower, in some cases, power savings reached 50%.
Other technologies
Today, there are three areas, the development of which will help make the work of data centers more efficient: the use of multi-core processors, embedded cooling systems and cooling at the chip level.
Computer manufacturers are confident that multi-core processors, completing more tasks in a short period, will reduce server power consumption by 40%. An example of the effectiveness of an integrated cooling system is the CoolFrame solution from Egenera and Emerson Network Power. It takes the hot air coming out of the servers, cools it and “throws” it into the room, thereby reducing the load on the main system by 23%.
As regards the cooling technology of the microcircuits, it allows the heat to be removed directly from the server’s hot spots, such as central processing units, graphic processing units and memory modules, to the surrounding air of the rack or outside the machine room.
Increasing energy efficiency today has become a real trend, which is not surprising, given the consumption of data centers: 25–40% of all operating expenses are accounted for by paying electricity bills. But the main problem is that every kilowatt-hour consumed by IT equipment is converted into heat, which is then removed with the help of cooling equipment that requires a lot of energy. Therefore, in the coming years, reducing the energy consumption of data centers will not cease to be relevant - there will be new ways to improve the energy efficiency of the data center.
Other materials from our blog on Habré:
Source: https://habr.com/ru/post/310630/
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