WO2012113808A1

WO2012113808A1 - A data centre rack comprising a plurality of servers with a control board

Info

Publication number: WO2012113808A1
Application number: PCT/EP2012/052963
Authority: WO
Inventors: Wilbert Ingels; Kristof Mark Guy De Spiegeleer
Original assignee: Dacentec Be Bvba
Priority date: 2011-02-22
Filing date: 2012-02-21
Publication date: 2012-08-30

Abstract

According to the invention there is provided a data centre rack (1) comprising a plurality of servers (20). Each of said plurality of servers (20) further comprising as server component a server control board (28) configured to execute server level measurement of server level parameters, said server control boards (28) being connected to a suitable control bus.

Description

A DATA CENTRE RACK COMPRISING A PLURALITY OF SERVERS WITH A

CONTROL BOARD

Field of the Invention

[01] The present invention generally relates to data centre equipment. Such data centres comprise a plurality of computing and/or storage equipment, usually in the form of a plurality of rack mounted servers. So called cloud data centres deliver large scale, raw capacity, i.e. storage and computing capacity to its customers. The present invention relates particularly to such a data centre rack and a data centre comprising such data centre racks that are particularly useful for such cloud data centres. Background of the Invention

[02] US714241 1 discloses a data centre rack for holding a large number of servers, with a reduced need for installing cables for providing power to the servers and makes use of a power bar. However the system disclosed requires a complex card cage as an intermediary for distributing the power and data connections in the rack. This system is almost completely enclosed and is not optimized for cooling the server components by means of an optimized air flow.

[03] Furthermore the monitoring and controlling the power usage of the servers is limited and is not easily scaled or automated to the level that is required for data centre racks for use in large scale data centres.

[04] The objective of this patent application is to teach building a data centre rack that can be provided with a rack level power distribution with an improved efficiency, cooled with an air flow as optimally as possible and that can be made more dense than traditional data centre racks and does not require a complex construction and has a simplified system for enabling more efficient measurement, monitoring and control of parameters such as for example power consumption of the individual servers. Summary of the Invention

[05] According to the invention there is provided a data centre rack, comprising:

· A rectangular box shaped frame comprising a top panel, a bottom panel and two side panels;

• A plurality of corresponding rail mechanisms arranged on both side panels;

• A rack level power supply providing electrical power to a plurality of power distribution means; and

· A plurality servers adapted to slide between both side panels into said corresponding rail mechanisms, said servers comprising as server components:

o At least one server level power supply connected to receive power from said plurality of power distribution means; and

o At least one server motherboard, powered by said server level power supply comprising at least one CPU

CHARACTERIZED IN THAT

• Said plurality of servers each comprise a case-less, metal server plate, adapted to slide into said corresponding rail mechanisms and whereon said server components are installed or mounted; and

• Said server level power supply of each of said plurality of servers being electrically connected in a releasable manner to said plurality of power distribution means by means of a power connector.

• each of said plurality of servers further comprising as server component a server control board configured to execute server level measurements of server level parameters, said server control boards being connected to a suitable control bus.

[06] This allows monitoring the server and controlling the server in a scalable and simple way even if the operating system of the server is not running or the server power supply is powered down. [07] According to an embodiment of the invention said server level parameters, as measured by suitable sensors which are provided as server components, comprise one or more of the following:

• server level power usage;

· server priority ranking;

• vibrations;

• temperature;

• humidity;

• water leak;

· motion;

• light intensity;

• smoke detection;

• server component status;

• sound detection;

· airflow.

[08] Preferably said control board is connected to said server motherboard by means of a suitable communication interface; and

said control board is configured to exchange said server level parameters with said server motherboard through said communication interface.

[09] In this way the server level parameters can be accessed by applications running on the motherboard and can in this way even be forwarded to suitable remote management systems by means of the network interfaces available.

[10] According to an embodiment of the invention said communication interface comprises one or more of the following:

• An IPMI interface; and/or

• An interface to the serial console of the motherboard.

[11] According to an alternative embodiment said data centre rack comprises a first server and a second server connected through a general purpose communication network; and said control board of the first server being connected to the motherboard of said first server through:

• the control bus connecting the control board of the second server to the control board of the first server;

· the communication interface connecting the control board of the second server to the server motherboard of the second server; and

• the general purpose communication network connecting the motherboard of the second server to the motherboard of the first server. [12] This allows the control board of the first server to be connected to the motherboard of the first server by a detour along the communication paths available through the second server.

[13] Preferably said data centre comprises means configured to aggregate said server level measurements of server level parameters to rack level measurements of rack level parameters.

[14] This allows not only to monitor and optimize server level parameters but also rack level parameters or a suitable combination of both.

[15] According to a preferred embodiment of the invention said control board is configured to selectively connect the server level power supply to one of said plurality of power distribution means based on said server level parameters and/or said rack level parameters.

[16] The system is especially useful when implemented to enable redundancy or load balancing for the rack level power supply.

[17] Preferably said control bus is formed by said plurality of power distribution means and that said server control board communicates over said control bus by means of a power line communications protocol enabling said control boards to exchange server level parameters such as the server level power usage and rack level parameters such as the rack level power usage and/or available power capacity of the rack level power supply. [18] In this way no separate control communication hardware links need to be provided. This further simplifies the design of the data centre rack and optimizes air flow along the server components.

[19] According to an embodiment of the invention said rack level parameters and/or server level parameters comprise one or more of the following:

- available capacity;

- uptime;

- quality history; and

- type of server level components or rack level components such as the type of rack level power supply.

[20] This enables to take into account for example the type of a plurality of alternative power feeds for the rack level or server level power supply which could be for example a power feed from a solar panel, a power feed from the grid, a UPS power feed and so on. In case the type is determined to be a UPS for example a parameter such as estimated run time can be provided in order to inform the system of the remaining operational time available before a controlled shut down or a minimal operation plan must be initiated.

[21] Preferably the server control board receives commands for connecting the server level power supply to one of said plurality of power distribution means from a central power control server, said central power control server configured to generate said commands on the basis of one or more Automatic Transfer Functions that are based on said server level parameters and/or said rack level parameters.

[22] This simplifies and automates the control of the power monitoring and control task for an operator of a large scale data centre.

[23] According to still a further embodiment said data centre rack comprises at least one of said servers and said central power control server being connected through a general purpose communication network; and said control board of this server being connected to the motherboard of this server through: • the control bus connecting the control board of this server to the central power control server; and

• the general purpose communication network connecting the central power control server to the motherboard of this server.

[24] This allows the control board of this server to be connected to the motherboard of this server by a detour along the communication paths available through the central power control server. [25] According to a preferred embodiment of the invention said rack level power supply comprises an Alternating Current to Direct Current power converter.

[26] This optimizes energy consumption as the server level power supply can be implemented as a DC/DC converter with a reduced capacity and size, allowing to further increase the number of servers installed in the data centre rack, while optimizing their power consumption and heat generation.

[27] Preferably said control board 28 comprises an Automatic Transfer Switch for selectively connecting the server level power supply to one of said plurality of power distribution means.

[28] In this way the glitches upon switching from one power distribution means to another are avoided. [29] According to an embodiment of the invention said servers further comprise as server component a server power connector for releasable connecting said server level power supply to said power distribution means.

[30] This allows for easy installation and removal of the server into the data centre rack.

[31] According to an embodiment of the invention said power distribution means are formed as a pair of non-isolated power bars extending along a direction parallel to both side panels between said top panel and said bottom panel. [32] Such an embodiment allows for a simple and cheap construction which minimizes the need for cabling and optimizes air flow along the server components.

[33] According to an alternative embodiment of the invention said power distribution means are formed as a power cord comprising a suitable connector for connecting to said server power connector.

[34] In this way the invention can be implemented using simple and reliable means. Brief Description of the Drawings

[35] Fig. 1 illustrates a data centre rack according to the invention;

[36] Figures 2 illustrate two alternative embodiments of a server installed in the data centre rack according to Figure 1

[37] Fig. 3 shows the server connector of the server of Fig. 2 in more detail;

[38] Fig. 4 shows the data centre rack of Figure 1 during insertion of a server;

[39] Fig. 5 shows the data centre rack according to Figure 1 without its servers;

[40] Fig. 6 shows an embodiment of the data centre rack according to the invention during insertion of a server;

[41] Fig. 7 shows the embodiment of Fig.6 when the server is inserted into the data centre rack; and

[42] Fig.8 schematically shows the main interactions between the server components of the servers of a data centre rack according to Figure 6.

Detailed Description of Embodiment(s) [43] Figure 1 shows a data centre rack 1 according to the invention. This data centre rack 1 comprises a rectangular box shaped frame that is formed by a top panel 12, a bottom panel 18 and two opposing side panels 14, 16, alternatively referred to as the right side panel 14 and left side panel 16. On both side panels 14, 16 corresponding rail mechanisms 10 are arranged, as more clearly visible in Figure 4. Each rail mechanism 10 on the right side panel 14 corresponds to a rail mechanism 10 on the left side panel 16 arranged at approximately the same height. These rail mechanisms are arranged at regular distances along the side panel in order to comply with the standard dimensions for modular data centre racks, which are often referred to as units of the rack. The rail mechanisms 10 of the data centre rack 1 as shown in Figure 1 are spaced apart with a distance corresponding to a single unit of such data centre rack 1 , which is generally referred to as 1 U. Figure 1 also shows the general directions which will be used when describing the embodiments of the data centre rack 1 according to the invention. Substantially vertical direction V is a direction parallel to the side panels 14, 16, which could be referred to as the height of the data centre rack 1 . Substantially horizontal directions H, D extend parallel to the top panel 12 and bottom panel 18. Direction H in a direction along the edge of the top panel 12 extending from one side panel 14 to the other side panel 16, which could be referred to as the width of the data centre rack. Direction D extends along the top edge of the side panel, which could be referred to as the depth of the data centre rack. Furthermore for the purpose of the description when referring to the front side of the data centre rack 1 this means the side indicated with reference F and when referring to the back side of the data centre rack 1 this means the side indicated with reference B, which are both arbitrary references only for the purpose of enabling a clear description of the embodiments of the invention.

[44] The data centre rack 1 comprises a rack level power supply 30, which is for example implemented as a rack mounted power converter that converts an incoming Alternating Current (AC) source, typically 208 V AC and converts it to a suitable Direct Current (DC) output, for example 48V DC. The rack level power supply 30 could optionally also comprise an Uninterruptible Power Supply (UPS), for example in the form of batteries, which is able to supply the required DC output even at times when the AC source is unavailable. [45] As shown in Figure 1 a plurality servers 20 are arranged in the data centre rack 1 . They are arranged horizontally between both side panels 14, 16. Each of these servers 20 is supported by a corresponding rail mechanisms 10 arranged on both side panels 14, 16. Each server 20 can further be individually inserted in or removed from the data centre rack by sliding it between both side panels 14, 16 on the corresponding rail mechanisms 10. The servers 20 are further dimensioned to take up a single unit of the data centre rack 1 , which is generally referred to as 1 U.

[46] Figure 2 shows an embodiment of the servers 20 in more detail. The servers 20 are formed from a case-less, metal server plate 22 that is designed to interact with the corresponding rail mechanisms for insertion in and removal from the servers 20 in the data centre rack 1 . On this server plate 22 server components are installed or mounted such as a server level power supply 60 and a server motherboard 24 comprising at least one Central Processing Unit (CPU) in the form of a processor that is powered by this server level power supply 60. It is clear that this server typically also comprises other components, such as a bus, a local memory, a communication interface, a storage element interface and a plurality of storage elements 26. The bus may include one or more conductors that permit communication among the components of server. The Processor may include any type of conventional processor or microprocessor that interprets and executes instructions. Local memory may include a random access memory (RAM) or another type of dynamic storage device that stores information and instructions for execution by processor and/or a read only memory (ROM) or another type of static storage device that stores static information and instructions for use by the processor. The communication interface may include any transceiver-like mechanism that enables the server 20 to communicate with other devices and/or systems, for example mechanisms for communicating with other servers 20 or computer systems such as for example two 1 Gb Ethernet interfaces and a serial port configured for providing access to a serial console of the server 20. The storage element interface may comprise a storage interface such as for example a Serial Advanced Technology Attachment (SATA) interface or a Small Computer System Interface (SCSI) for connecting the bus to one or more storage elements 26, such as one or more local disks, for example 2TB SATA-II disk drives, or a solid state drive and control the reading and writing of data to/from these storage elements. [47] Further server components mounted on the server plate 22 as shown in the embodiment of Figure 2 are a server control board 28 and a connector 50 which will be described in more detail below.

[48] It is clear that the servers 20, also called "plate servers", as shown in the embodiment of Figures 2 do not have any casing and have all server components installed on a metal server plate 22. This allows for a very simple construction, that maximizes the space available in the data centre rack 1 for the server components and optimizes air flow along these components for cooling purposes. This metal server plate 22, can be manufactured from any suitable metal material such as for example iron. The embodiment of the server 20 shown in Figure 2 comprises as server components, next to the motherboard 24 and server level power supply 60, a plurality of storage elements 26, for example in the form of hard discs. Such a server 20 can be referred to as a so called "storage plate". According to an alternative embodiment of the server, also referred to as a "CPU plate", the server has mainly as server components a more limited amount of storage elements 26 in the form of a hard disk and a solid state drive and has for example an Infiniband communication link available. Preferably the networking connections are all foreseen at the front side of the plates servers 20 and according to one embodiment all plate servers 20 have available Gigabit Ethernet connections and CPU plate servers 20 have additionally available 40 Gbit/s Infiniband connections.

[49] The power bar connector 50 of Figure 2, is shown in Figure 3 in more detail and comprises a mechanism that contacts with the power bars 42, 44 and 46, 48 when sliding the server 20 into the data centre rack 1 . The server 20 is fixed to the frame or the rails 10 of the data centre rack by means of a suitable releasable connection, preferably at the front side of the rack, such as a bolt connection or a suitable releasable click mechanism.

[50] Figure 4 shows one of the servers 20 during insertion into or extraction out of the data centre rack 1 . During such an operation the server 20 slides along the corresponding rail mechanisms 10. The plate servers 20 all have a 1 U size and one data centre rack 1 for instance holds 42 plate servers 20. Installation and replacement can be done easily and fast.

[51] Figure 5 shows the data centre rack 1 of Figure 1 when all servers 20 have been removed in order to more clearly show the arrangement of the rail mechanisms 10 and the bottom panel 18.

[52] As shown in more detail in Figures 6 and 7 the data centre rack 1 comprises two pairs of non-isolated bars 42, 44, 46, 48 extending along the direction V parallel to both side panels 14, 16 between the top panel 12 and the bottom panel 18. These non-isolated bars are formed of an electrically conductive material, preferably a metal such as copper or iron. Each pair of these power bars 42, 44 and 46, 48 can more generally be referred to as a power distribution means 43 and 45. According to an alternative embodiment, the power distribution means 43, 45 could also be formed as a suitable power cord comprising a suitable connector for connecting to the server power connector 50. The rack level power supply 30 is electrically connected to this pair of power distribution means 43, 45 and feeds each of them with a DC output of for example 48V in order to distribute this output power to the servers 20 mounted in the data centre rack 1 . The pair of power distribution means 43, 45 makes it possible to provide for two separate circuits for providing power to the servers 20 in function of redundancy or in the case the rack level power supply comprises multiple power converters to enable load balancing.. The servers 20 from their side selectively connect, by means of the server control board 28, and additionally preferably in a releasable manner their server level power supply 60 to this pair of power distribution means 43, 45 by means of a server power connector 50. In order to select one of the pair of power distribution means 43, 45 for connecting it to the server level power supply 60 the server control board 28 comprises suitable components such as a relay or a FET or an Automatic Transfer Switch 104 as schematically shown in Figure 8. The server level power supply 60 then converts the intermediate DC voltage from the selected power distribution means 43 or 45 to the final DC voltage needed by the server components, which is usually 12V and/or 5V. This way of distributing the power eliminates allows the server level power supply 60 to operate more efficiently, to be designed more economical and generate less heat as the final power conversion step from the intermediate DC voltage will result in less energy loss then a direct conversion from a higher voltage AC source. Typically energy losses are reduced with at least 30%. The reduced need for installing cables in the data centre rack 1 also allows for a more efficient airflow along the server components and allows to insert and remove the servers 20 from the data centre rack 1 more easily.

[53] The server power connector, according to the embodiment shown in Figures 6 and 7 can be formed as the power bar connector 50 shown in Figure 3 in more detail and comprises a mechanism that contacts with the pair of power bars 42, 44 or 46, 48 when sliding the server 20 into the data centre rack 1 . The server 20 is fixed to the frame or the rails 10 of the data centre rack 1 by means of a suitable releasable connection, preferably at the front side of the rack, such as a bolt connection or a suitable releasable click mechanism.

[54] As already shown above with respect to Figure 2, 6 and 7, each server 20 comprises a server control board 28. This control board 28 is electrically connected in a releasable manner to a suitable control bus 100 as schematically shown in Figure 8, which connects all control boards 28 of the servers 20 installed in the rack with each other and optionally with a central power management system 102 as for example shown in Figure 8. The control bus 100 enables the server control board 28 to send and receive commands and/or data. Generally the server control boards 28 are configured to receive and send commands and data through the control bus as if it were a serial communication link.

[55] Preferably the server control board 28 is directly connected to the pair of power distribution means 43, 45 through the server power connector 50 and derives its power directly from this intermediate DC voltage and is able to selectively connect the server power supply 60 to one of the power distribution means 43, 45 as described above. In this way the control board 28 will be able to operate even if the server level power supply 60 is shut down or inoperative and be able to perform operations such as powering the server 20 up or down by controlling the server level power supply 60.

[56] According to still further alternative embodiments there could be arranged more than two power distribution means 43, 45, this means for example more than two pairs of power bars, there could for example be provided four, six or more power bars, each powered by for example a separate power converter of the rack level power supply 30 in order to distribute the power capacity or in order to provide redundancy. The server control board 28 is preferably also connected to the server motherboard 24 by means of an IPMI interface (Intelligent Platform Management Interface) for measuring processor temperature, motherboard temperature, hard disk temperatures; and/or an interface to the serial console of the motherboard allowing remote access and management. The setup according to the invention is advantageous with respect to a traditional terminal server setup as no rack level wiring needs to be installed that links directly to the serial console of the server motherboard 24. This simplifies the logical and physical architecture for providing remote management access to a large number of servers 20 and eliminates the need for a KVM system to remotely access the server 20 and/or the respective server control board 28.

[57] The servers 20 could optionally also be provided with one or more of suitable sensors for measuring: server level power usage; server priority ranking; vibrations, temperature, motion, light intensity; smoke detection; server component status; sound detection; or airflow connected in a suitable way to the server control board 28. The server control board is then able to transmit the measurements of these sensors through the control bus 100 or use it in accordance with parameters that were provided through the control bus 100 to control the status of some of the server components, such as for example selectively connecting the server level power supply 60 to one of the power distribution means 43 or 45. In order to receive data and process data sent over the control bus 100 and/or send parameters or commands to the server control boards 28 of the servers 20 the data centre rack 1 could be equipped with a central power control server 102, but alternatively the power control server 102 might equally be implemented as a functionality of one or more of the plate servers 20 installed in the rack. In this way measured server level power usage, temperature, airflow, humidity, ... or parameters such as server level priority ranking can be aggregated from the server level measurements and/or server level parameters to rack level measurements and/or rack level parameters such as rack level power usage or rack level priority ranking and can be made available to an operator for example by means by generating alarms to take actions when needed, such as for example shutting down overheated servers to avoid further overheating inside the rack or adapting the air flow system when possible or needed. It is clear that power usage can be calculated from the measured voltage and current in the power distribution means or when the voltage is at least approximately known can be calculated from the current in the power distribution means alone. An alternative action involves measuring the load state of machines: servers that are idle or that have too much load can have their load migrated to other servers. It is also clear that the servers 20 of the data centre rack 1 could further be suitably connected to a general purpose data communication network 106 as schematically shown in Figure 8.

[58] According to an embodiment as schematically shown in Figure 8, the server level parameters and/or rack level parameters are communicated to the server control boards 28 through the control bus 100 in order to automatically connect the respective server level power supplies 60 to one of the power distribution means 43 or 45. In one situation where it is detected that the power capacity of the power convertor connected to the first power distribution means 43 is almost fully loaded and the power convertor of a second power distribution means 45 has still available sufficient capacity, when inserting a new server 20 into the data centre rack 1 , its server control board 28 will automatically connect its server power supply 60 to the second power distribution means 45. In an alternative embodiment, if one of the power convertors supplying the first power distribution means 43 fails, the server control board 28 upon detection of this event or upon receiving a suitable command will switch the server power supply 60 to the second power distribution means 45 if its power capacity still allows it. Based on the server level measurements of server level parameters decisions can be taken to optimize the data centre rack situation at server level and reduce the energy usage adaptively. Furthermore power transfer at the level of the servers is easier and safer to do than power transfers of higher loaded power feeds.

[59] According to a preferred embodiment of the invention the control bus 100 of a data centre rack 1 is formed by the plurality of power distribution means 43, 45. In this case the control board 28 communicates over the control bus 100 by means of a power line communications protocol. This enables the control boards 28 to exchange server level parameters such as the server level power usage and rack level parameters such as the rack level power usage and/or available power capacity of the rack level power supply 30 without requiring additional cables or connectors but those already available for the power distribution means 43, 45 and the associated server power connectors 50. This can be implemented by providing current modulated information on top of the intermediate DC output of the rack level power supply for automated power management. In this way ATS (Automatic Transfer Switch) for power is brought to the level of a data center rack 1 and even to the level of a server 20 within such a data centre rack 1 . Inside the data centre rack 1 , different power distribution means 43, 45 arrive from different power sources, e.g. one or more power converters or Uninterruptible Power Supplies (UPS) from the rack level power supply 60. The server control boards 28 and/or the power control server 102 will use the power distribution means 43, 45 as a bidirectional control bus 100 for communicating information about the power usage in order to for example determine the available capacity of each of the power distribution means 43, 45. Preferably the control boards 28 and/or the power control server 102 is able to store and analyze historical information such as for example rack level parameters and/or server level parameters comprising one or more of the following: available capacity; uptime; quality history; and type of server level components or rack level components such as the type of rack level power supply 30 which could for example be provided with power from solar panels or a power feed derived from the grid.

[60] According to a preferred embodiment of the invention the server control board 28 receives commands for connecting the server level power supply 60 to one of the plurality of power distribution means 43, 45 from a central power control server 102 automatically. In order to provide these automatic commands the power control server 102 generates these commands on the basis of one or more Automatic Transfer Functions that are based on said server level parameters and/or said rack level parameters. Such an Automatic Transfer Function comprises logic expressions comprising parameters that preferably can be set by an operator to automatically calculate from the server level parameters and/or rack level parameters which power distribution means 43, 45 the control board 28 must select. This is especially usefull if the power feeds that feed the power converters or UPS of the rack level power supply 60 are derived from a plurality of different power feeds from one or more utility companies or feeds delivered by generators or feeds from other on-site energy generating technology like solar panels or wind energy, which differ largely in availability and/or quality. Preferably each switch over from one power distribution means to another by the control board 28 is implemented as an ATS (Automatic Transfer Switch) function that handles the switchover between currents seamlessly. In this way all ATS functionality is made available and can be monitored and controlled through the control bus 100 for example by the central power control server 102. In this way the servers 20 will be able to access multiple power feeds available in the data center 1 flexibly and automatically which reduces the possibility of mistakes during power capacity planning and management, as up to date parameters and information are available directly on the power distribution means 43, 45 itself. This technique can also be referred to as "generator virtualization of power feed generation". This is especially useful in large scale data centers in which there is a tendency to maximize the number of servers 20 per data centre rack 1 in order to provide scalable storage and computing facilities and in which there is also a tendency to optimize the energy consumption and ease of maintenance in order to limit operational costs. It is also clear that the central power control server 102 can optionally be provided with a suitable connection to the general purpose communication network 106, as schematically shown in Figure 8, for example to allow for remote access by an operator during configuration or maintenance of the data center rack 1 .

[61] According to a further alternative embodiment of the invention, as schematically illustrated in Figure 8, the control board 28 of a first server 20 can be connected to the motherboard 24 of this server through a detour along a second server 20 of the data centre rack 1. This might be a useful alternative if the direct communication path from the control board 28 to the motherboard of the first server 20 is unavailable. In order to enable this embodiment the data centre rack 1 must comprises a first server 20 and a second server 20 connected through a general purpose communication network 106. The control board 28 of the first server 20 can then be connected to the motherboard 24 the said first server 20 through the following bidirectional communication path. First the control bus 100 connects the control board 28 of the second server 20 to the control board 28 of the first server 20. Subsequently the communication interface connects the control board 28 of the second server 20 to the server motherboard 24 of the second server 20. Finally the general purpose communication network 106 connects the motherboard 24 of the second server 20 to the motherboard 24 of the first server 20. [62] According to still a further alternative embodiment of the invention, as schematically illustrated in Figure 8, the control board of one or more of the servers 20 of the data centre rack 1 can be connected to the motherboard 24 of the respective servers 20 by a detour along the communication paths available through the central power control server 102. In order to enable this the data centre rack 1 connects at least one of the servers 20 and the central power control server 102 by means of the general purpose communication network 106. The control board 28 of this server 20 can then be connected to the motherboard 24 of this server 20 through the following bidirectional communication path. First the control bus 100 connects the control board 28 of this server 20 to the central power control server 102. Finally the general purpose communication network 106 connects the central power control server 102 to the motherboard 24 of this server 20.

[63] Although the present invention has been illustrated by reference to specific embodiments, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied with various changes and modifications without departing from the scope thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. In other words, it is contemplated to cover any and all modifications, variations or equivalents that fall within the scope of the basic underlying principles and whose essential attributes are claimed in this patent application. It will furthermore be understood by the reader of this patent application that the words "comprising" or "comprise" do not exclude other elements or steps, that the words "a" or "an" do not exclude a plurality, and that a single element, such as a computer system, a processor, or another integrated unit may fulfil the functions of several means recited in the claims. Any reference signs in the claims shall not be construed as limiting the respective claims concerned. The terms "first", "second", third", "a", "b", "c", and the like, when used in the description or in the claims are introduced to distinguish between similar elements or steps and are not necessarily describing a sequential or chronological order. Similarly, the terms "top", "bottom", "over", "under", and the like are introduced for descriptive purposes and not necessarily to denote relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and embodiments of the invention are capable of operating according to the present invention in other sequences, or in orientations different from the one(s) described or illustrated above.

Claims

1 . A data centre rack (1 ), comprising:

• A rectangular box shaped frame (10) comprising a top panel (12), a bottom panel (18) and two side panels (14, 16);

• A plurality of corresponding rail mechanisms (10) arranged on both side panels

(14, 16);

• A rack level power supply (30) providing electrical power to a plurality of power distribution means (43, 45); and

· A plurality servers (20) adapted to slide between both side panels (14, 16) into said corresponding rail mechanisms (10), said servers (20) comprising as server components:

o At least one server level power supply (60) connected to receive power from said plurality of power distribution means (43, 45); and o At least one server motherboard (24), powered by said server level power supply (60) comprising at least one CPU

CHARACTERIZED IN THAT

• Said plurality of servers (20) each comprise a case-less, metal server plate (22), adapted to slide into said corresponding rail mechanisms (10) and whereon said server components are installed or mounted; and

• Said server level power supply (60) of each of said plurality of servers (20) being electrically connected in a releasable manner to said plurality of power distribution means (43, 45) by means of a power connector (50).

• each of said plurality of servers (20) further comprising as server component a server control board (28) configured to execute server level measurements of server level parameters, said server control boards (28) being connected to a suitable control bus (100).

2. A data centre rack according to claim 1 , characterised in that said server level parameters, as measured by suitable sensors which are provided as server components, comprise one or more of the following:

• server level power usage;

• server priority ranking; vibrations;

temperature;

humidity;

water leak

motion;

light intensity;

smoke detection;

server component status;

sound detection;

airflow.

3. A data centre rack according to claim 1 or 2, characterised in that said control board (28) is connected to said server motherboard (24) by means of a suitable communication interface; and

said control board (28) is configured to exchange said server level parameters with said server motherboard (24) through said communication interface.

4. A data centre rack according to claim 3, characterised in that said communication interface comprises one or more of the following:

· An IPMI interface; and/or

• An interface to the serial console of the motherboard.

5. A data centre rack according to claim 3 or 4, characterised in that said data centre rack comprises a first server (20) and a second server (20) connected through a general purpose communication network (106); and said control board (28) of the first server (20) being connected to the motherboard (24) of said first server (20) through:

• the control bus (100) connecting the control board (28) of the second server (20) to the control board (28) of the first server (20);

· the communication interface connecting the control board (28) of the second server (20) to the server motherboard (24) of the second server (20); and • the general purpose communication network (106) connecting the motherboard (24) of the second server (20) to the motherboard (24) of the first server (20).

6. A data centre rack according to any of the preceding claims; characterised in that said data centre comprises means (102) configured to aggregate said server level measurements of server level parameters to rack level measurements of rack level parameters.

7. A data centre rack according to claim 6, characterised in that said control board is configured to selectively connect the server level power supply (60) to one of said plurality of power distribution means (43, 45) based on said server level parameters and/or said rack level parameters.

8. A data centre rack according to any of the preceding claims, characterized in that said control bus (100) is formed by said plurality of power distribution means (43, 45) and that said server control board (28) communicates over said control bus (100) by means of a power line communications protocol enabling said control boards (28) to exchange server level parameters such as the server level power usage and rack level parameters such as the rack level power usage and/or available power capacity of the rack level power supply (30).

9. A data center rack according to claim 8, characterized in that said rack level parameters and/or server level parameters comprise one or more of the following:

- available capacity;

- uptime;

- quality history;

- type of server level components or rack level components such as the type of rack level power supply (30);

- estimated run time.

10. A data center rack according to claim 6 to 9, characterized in that the server control board (28) receives commands for connecting the server level power supply to one of said plurality of power distribution means (43, 45) from a central power control server (102), said central power control server configured to generate said commands on the basis of one or more Automatic Transfer Functions that are based on said server level parameters and/or said rack level parameters.

1 1 . A data centre rack according to claim 10, characterised in that said data centre rack comprises at least one of said servers (20) and said central power control server (102) being connected through a general purpose communication network (106); and said control board (28) of this server (20) being connected to the motherboard (24) of this server (20) through:

· the control bus (100) connecting the control board (28) of this server (20) to the central power control server (102); and

• the general purpose communication network (106) connecting the central power control server (102) to the motherboard (24) of this server (20).

12. A data centre rack according to any of the claims 7 to 1 1 , characterised in that said control board 28 comprises an Automatic Transfer Switch for selectively connecting the server level power supply (60) to one of said plurality of power distribution means (43, 45).

13. A data centre rack according to any of the preceding claims, characterised in that said rack level power supply (30) comprises an Alternating Current to Direct Current power converter.

14. A data centre rack according to any of the preceding claims, characterised in that said power distribution means (43, 45) are formed as a pair of non-isolated power bars (42, 44; 46, 48) extending along a direction (V) parallel to both side panels (14, 16) between said top panel (12) and said bottom panel (18).

15. A data centre rack according to any of the claims 1 to 14, characterised in that said power distribution means (43, 45) are formed as a power cord comprising a suitable connector for connecting to said server power connector (50).