USOO6978346B2
`
`(12) United States Patent
`US 6,978,346 B2
`(10) Patent N0.:
`
` Baek et al. (45) Date of Patent: Dec. 20, 2005
`
`
`(54) APPARATUS FOR REDUNDANT
`INTERCONNECTION BETWEEN MULTIPLE
`HOSTS AND RAID
`
`................ 714/4
`8/2003 Nguyen 61 61.
`6,609,213 131*
`............... 711/114
`6,820,171 131* 11/2004 Weber et 61.
`OTHER PUBLICATIONS
`
`(75)
`
`Inventors: Sung-Hoon Baek, Taejon (KR);
`Joong-Bae Kim, Taejon (KR);
`Yong-Youn Kim, Taejon (KR)
`
`(73) Assignee: Electronics and Telecommunications
`Reseach Institute, (KR)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 856 days.
`
`(21) Appl. No.: 09/753,245
`
`(22)
`
`Filed:
`
`Dec. 29, 2000
`
`(65)
`
`Prior Publication Data
`
`US 2002/0035669 A1
`
`Mar. 21, 2002
`
`(30)
`
`Foreign Application Priority Data
`
`Sep. 19, 2000
`
`(KR)
`
`............................... 2000-54807
`
`G06F13/00;G06F 12/00
`Int.Cl.7
`(51)
`
`711/114,709/250
`...............
`(52) U.S.Cl.
`(58) Field of Search ................................ 709/201—203,
`709/217—219,223—224, 239—240, 244, 250,
`711/114, 710/38; 370/360, 412
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`4,652,536 A
`5,251,062 A
`5,798,306 A
`5,812,754 A *
`6,192,485 B1 *
`
`3/1987 Nakajima et a1.
`10/1993 Snitzer et a1.
`8/1998 Dickinson, Jr.
`9/1998 Lui et al. ....................... 714/6
`2/2001 Takita et al.
`................... 714/6
`
`Tellurite glass: a new candidate for fiber devices by J .S.
`Wang: Optical Materials 3 (1994) 187-203.
`Structure and optical properties of rare earth doped Zinc
`oxyhalide tellurite glasses by D.L. Sidebottom: Journl of
`Non-Crystalline Solids 222 (1997), pp. 282-289.
`Raman spectra snd thermal analysis of a new lead-tellurium-
`germanate glass system by Z. Pan: Journl of Non-Crystalline
`Solids 210 (1997), pp. 130-135.
`
`* cited by examiner
`
`Primary Examiner—Krisna Lim
`(74) Attorney, Agent, or Firm—Blakely Sokoloff Taylor &
`Zafman
`
`(57)
`
`ABSTRACT
`
`interconnection between
`The apparatus for a redundant
`multiple hosts and a redundant array of inexpensive disks
`(hereinafter, referred to as ‘RAID’), which is capable of
`supporting a fault tolerance of RAID controllers and simul-
`taneously heightening a performance, comprises a plurality
`of RAID controlling units for processing a requirement of
`numerous host computers connected with one another
`through the industrial standard communication network and
`for fault tolerance; a plurality of connecting units for con-
`necting the plurality of RAID controlling units to the numer-
`ous host computers; and a plural number of network inter-
`face controlling units
`respectively contained into the
`plurality of RAID controlling units, for exchanging infor-
`mation directly with an opposite network interface control-
`ling unit provided within an opposite RAID controlling unit
`-
`and the numerous host computers, through the plurahty of
`connecnng umts'
`
`9 Claims, 6 Drawing Sheets
`
`, ______ 139°
`HOST COMPUTERI
`
`INTERFACE
`CONTROLLER
`
`r—'-——‘—"———
`
`I._..._.__.__
`
`,_________
`
`r______ 1.425
`I
`HOST COMPUTERI
`|
`H
`415
`i
`
`______1.422,______1.492 _____ 1.423,. ______ 1.494
`IHOST COMPUTER l
`l HOST COMPUTERIIHOST COMPUTERI IrHOST COMPUTERI
`411 “
`412
`i u.”
`413'
`7 ,
`414'
`INTERFACE
`CONTROLLER
`
`|_________
`
`,____..___-
`
`
`
`EEC;-
`Fflfi‘Ffl-mi!
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`r
`
`m-
`NETWORK INTERFACE NETWORK INTERFACE
`commuen
`
`VMWARE-1001
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`US. Patent
`
`Dec. 20, 2005
`
`Sheet 1 0f 6
`
`US 6,978,346 B2
`
`F I G.
`
`1
`
`--PRIOR ART—-
`
`100
`I— __________ “L _ _ '1
`I
`HOST COMPUTER
`I
`I
`110
`I
`I
`NETWORK INTERFACE
`I
`I
`CONTROLLER
`I
`I
`I
`I
`I
`_____ J
`
`101
`I— __________ TL _ — “I
`I
`HOST COMPUTER
`I
`I
`111
`I
`I
`NETWORK INTERFACE
`I
`I
`CONTROLLER
`I
`I
`I
`I
`I
`_ _ _ _ _ .J
`
`
`
`NETWORK INTERFACE
`CONTROLLER
`
`NETWORK INTERFACE
`CONTROLLER
`
`I"
`
`II I I l l l IL
`
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`US. Patent
`
`Dec. 20, 2005
`
`Sheet 2 0f 6
`
`US 6,978,346 B2
`
`F I G . 2
`-—PRIOR ART——
`
`201
`200
`I- —————————— _/— — — ‘I
`I- ——————————L — — ‘I
`I
`HOST COMPUTER
`I
`I
`HOST COMPUTER
`I
`I
`I
`I
`I
`NETWORK INTERFACE
`I
`I
`NETWORK INTERFACE
`I
`I
`
`
`CONTROLLER
`I
`I
`CONTROLLER
`I
`I
`
`l
`I
`I
`I
`I
`I
`I
`I
`L __________ .I
`L __________ J
`
` HUB OR SWITCH
`
`T I
`
`
`I—_“___"———_'I
`
`
`w WEE-IEI|
`.I ri rt
`Iii I:H
`
`
`Ii
`
`:|J
`
`
`
`
`
`NETWORK
`COMMUNI-
`COMMUNI-
`CATION
`CATION
`INTERFACE
`
`
`
`
`CONTROLLER
`CONTROLLER
`
`
`
`
`
`220
`221
`RAID CONTROLLER
`
`
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`US. Patent
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`Dec. 20, 2005
`
`Sheet 3 0f 6
`
`US 6,978,346 B2
`
`FIG. 3
`--PRIOR ART--
`
`NETWORK INTERFACE
`CONTROLLER
`
`NETWORK INTERFACE
`CONTROLLER
`
`CONTROLLER
`
`NEIWORK
`
`INTERFACE
`CONTROLLER
`
`INTERFACE
`
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`US. Patent
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`Dec. 20, 2005
`
`Sheet 4 0f 6
`
`US 6,978,346 132
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`VMWARE-1001 / Page 5 of 10
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`VMWARE-1001 / Page 6 of 10
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`US. Patent
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`2B643,879,6SU
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`US 6,978,346 B2
`
`1
`APPARATUS FOR REDUNDANT
`INTERCONNECTION BETWEEN MULTIPLE
`HOSTS AND RAID
`
`FIELD OF THE INVENTION
`
`The present invention relates to an apparatus for a redun-
`dant interconnection between multiple host computers and a
`redundant arrays of inexpensive disks (hereinafter, referred
`to as ‘RAID’); and, more particularly, to an apparatus for a
`redundant interconnection between multiple host computers
`and multiple controllers of the RAID, which is capable of
`supporting a fault tolerance of the RAID controllers and
`simultaneously heightening performance.
`
`PRIOR ART OF THE INVENTION
`
`ARAID is a storage system based on a large capacity and
`a high performance, by using much quantity of disks, and is
`a fault tolerant system in which the disks or controllers etc.
`have a redundant nature. In general, the RAID has two
`controllers, which are used like a method shown in FIG. 1
`or 2.
`
`FIG. 1 is an exemplary block diagram showing a general
`connection method between the host computers and the
`RAID having the conventional two controllers.
`As shown in the drawing, the RAID 130 includes two
`RAID controllers 140, 141 and each of RAID controllers
`140, 141 includes network interface controllers 150, 151.
`The network interface controllers 150, 151 of the RAID
`controllers 140, 141 are independently connected to network
`interface controllers 110, 111 of the host computers 100, 101
`through communication links 120, 121 such as a copper line
`and an optical fiber. That is, such system has twice the
`bandwidth and twice the performance. However, there is
`such a problem that a loss of data occurs when one out of
`two RAID controllers 140, 141 has a trouble, in other words,
`this system does not become the fault tolerant system.
`FIG. 2 is an exemplary block diagram of a general host
`interface system having a communication interface for an
`error recovery between the conventional two controllers.
`In order to provide fault tolerance not provided in FIG. 1,
`RAID 240 includes two RAID controllers 230, 231 and two
`RAID controllers 230, 231 and host computers 200, 201 are
`connected with each other through a hub or switch 210 in
`one network. The RAID controller 230 includes a pair of
`network interface controllers 220 and 221 and the RAID
`
`controller 231 includes a pair of network interface control-
`lers 222 and 223. Thus, even though one RAID controller
`230 or 231 has a trouble, all of the host computers 200, 201
`are connected to a RAID controller that does not have a
`
`trouble. That is, this RAID controller not having the trouble
`serves as a role of the controller that has the trouble. Also,
`since the RAID controllers 230, 231 should exchange infor-
`mation with each other by preparing in advance against
`some trouble, the RAID controllers 230, 231 are connected
`with each other through communication controllers 221,
`222. However, in this case only a half of performance for the
`bandwidth provided in FIG. 1 can be obtained.
`FIG. 3 is an exemplary block diagram showing a wiring
`method between a conventional RAID and the host com-
`puters.
`The construction shown in the drawing partially repre-
`sents a systematic connection between a RAID and host
`computers, which is extracted from contents disclosed in the
`US, Pat. No. 5,812,754. The RAID 340 includes two RAID
`controllers each of which has network interference control-
`
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`2
`lers 330, 331 and four ports 310, 311, 320 and 321. How-
`ever, this construction has no any difference from that of
`FIG. 2, in the structure of a communication network, and in
`case that one out of two host computers 300, 301 has rather
`a trouble, there is caused a problem that a network is broken.
`Thus, this construction is inferior to the construction of FIG.
`2.
`
`SUMMARY OF THE INVENTION
`
`invention to
`is an object of the present
`it
`Therefore,
`provide an apparatus for
`a
`redundant
`interconnection
`between multiple host computers and a RAID, which is
`capable of supporting a fault tolerance of a RAID controller
`and simultaneously heightening a performance.
`In accordance with the present invention, the apparatus
`for a redundant interconnection between multiple hosts and
`a RAID comprises a plurality of RAID controllers for
`processing requests of numerous host computers connected
`with one another through an industrial standard communi-
`cation network such as fibre channel and performing fault
`tolerant function; a plurality of connecting units for con-
`necting the plurality of RAID controllers to the numerous
`host computers; and a plural number of network interface
`controllers respectively contained into the plurality of RAID
`controllers,
`the network interface controllers being for
`exchanging information directly with each of opposite net-
`work interface controllers provided within the numerous
`host computers and within opposite RAID controllers,
`through the plurality of connecting units.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The above and other objects and features of the instant
`invention will become apparent from the following descrip-
`tion of preferred embodiments taken in conjunction with the
`accompanying drawings, in which:
`FIG. 1 is an exemplary block diagram showing a general
`connection system between host computers and a RAID
`having conventional two controllers;
`FIG. 2 indicates an exemplary block diagram of a general
`host interface system having a communication interface for
`an error recovery between the conventional two controllers;
`FIG. 3 illustrates an exemplary block diagram of a wiring
`method between a conventional RAID and host computers;
`FIG. 4 is a block diagram showing one embodiment of a
`host
`interface system as an internal
`installment system
`between a RAID and host computers in accordance with the
`present invention;
`FIG. 5 depicts a block diagram providing one embodi-
`ment of a host interface system as an external installment
`system between a RAID and host computers in the present
`invention; and
`FIG. 6 is a block diagram showing one embodiment of a
`host interface system as a network switch between a RAID
`and host computers in the invention.
`
`PREFERRED EMBODIMENT OF THE
`INVENTION
`
`Hereinafter, preferred embodiments of the present inven-
`tion will be described in detail with reference to the accom-
`
`panying drawings.
`FIG. 4 is a block diagram showing one embodiment of a
`host matching system as an internal
`installment system
`between a RAID and host computers in accordance with the
`present invention.
`
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`US 6,978,346 B2
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`3
`interface
`in the inventive host
`As shown in FIG. 4,
`system, a communication circuit is provided in order for an
`error recovery between two RAID controllers 460, 461, and
`the bandwidth between two groups as the host computers
`400 to 405 and two RAID controllers 460, 461 becomes
`twice the single connection bandwidth. Also, in the inven-
`tive host interface system, even though one RAID controller
`460 or 461 has an occurrence of a trouble, the bandwidth
`becomes twice the single connection bandwidth.
`That is to say, in a RAID 490, two RAID controllers 460,
`461 and hubs 440, 441 exist, and in each of the RAID
`controllers 460, 461, a pair of network interface controllers
`470, 471; 480, 481 are provided. Herewith, the hubs 440,
`441 are provided to connect a system connected to these
`hubs by one network and maintain the network even though
`one system has an occurrence of a trouble or a short of a line,
`and it can be as a hub or a switch. Hereinafter, they are
`named a “hub” altogether.
`Hub ports, 420 to 424, 430 to 434, shown in FIG. 4
`indicate an example for a simple internal structure of a fibre
`channel arbitrated loop hub, and this is based on an already
`well-known technique, thus there will be herein no more
`description therefore in the invention. The hub observes its
`corresponding communication network standard.
`A network, in which the RAID controllers, the hubs and
`the host computers are connected with one another, corre-
`sponds to the industrial standard communication network
`such as fibre channel, asynchronous transfer mode (ATM)
`and InfiniBand etc. and they are hereinafter named a ‘net-
`work’.
`Network interface controllers, 410 to 415, contained into
`the host computers, 400 to 405, and the network interface
`controllers 470, 471, 480, 481 of the RAID controllers 460,
`461 are connected with one another by two networks
`through two hubs 440, 441, and according to a sort of the
`networks, the network interface controller becomes a fibre
`channel controller, an ATM controller and an InfiniBand
`controller etc.
`
`representatively
`this time, a communication line,
`At
`shown as 450 in the drawing, for connecting the network
`interface controller to the hub is a copper line or an optical
`fibre, which is matched to a corresponding standard.
`Meanwhile, two network interface controllers 470, 471 of
`the first RAID controller 460 are respectively connected to
`two different hub ports 423, 432, and two network interface
`controllers 480, 481 of the second RAID controller 461 are
`respectively connected to two different hub ports 422, 433.
`The rest ports 420, 421, 424, 430, 431, 434 of the hubs 440,
`441 are connected to the host computers 400 to 405. Just,
`there is no distinction between the hub ports 420 to 424 of
`the first hub 440 at all. Also, there is no distinction between
`the hub ports 430 to 434 of the second hub 441 at all.
`The hub port connected to the host computer among the
`hub ports of the hub 440, namely, 420, 421, 424, is more
`than one, and there is no limitation to the maximum number.
`Further, What it is connected to the host computer among the
`hub ports of the second hub 441, namely, 430, 431, 434, is
`more than one, and there is no limitation to the maximum
`number. The hub ports 424, 434 and the host computers 400,
`405, which are shown as dot lines in FIG. 4, mean that there
`is no, or more than one hub port or host computer.
`Since, in such construction, two independent networks are
`constructed; it has twice the bandwidth of the single net-
`work, and a communication passage between two RAID
`controllers needed to perform the fault tolerant function of
`two RAID controllers 460, 461 is formed. Thus, information
`from the second network interface controller 471 of the first
`
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`RAID controller 460 is sent to the first network interface
`controller 481 of the second RAID controller 461. Also,
`information from the second network interface controller
`480 of the second RAID controller 461 is transmitted to the
`first network interface controller 470 of the first RAID
`controller 460. Further, information from the first network
`interface controller 481 of the second RAID controller 461
`is transmitted to the second network interface controller 471
`of the first RAID controller 460, and information from the
`first network interface controller 470 of the first RAID
`controller 460 is sent
`to the second network interface
`controller 480 of the second RAID controller 461.
`The first network interface controllers 470, 480 of two
`RAID controllers 460, 461 respectively supply data of the
`host computers 400 to 402 connected to the first hub 440 and
`the host computer 403 to 405 connected to the second hub
`441, and process information transmitted from the opposite
`network interface controllers 471, 481.
`If any one out of two RAID controllers 460, 461 has an
`occurrence of an error, the RAID controller having the error
`occurrence is removed from the network, and a second
`network interface controller of an opposite RAID controller
`not having the error occurrence takes over a function of a
`first network interface controller of the RAID controller
`
`having the error occurrence.
`FIG. 5 is a block diagram providing one embodiment of
`the host interface system as an external installation system
`between the RAID and the host computers in the present
`invention.
`
`As shown in FIG. 4, the present invention can be con-
`structed by a method of internally installing the hubs 440,
`441 in the RAID 490, and as shown in FIG. 5, the host
`computers 500, 501, 502, 503, 504 and 505 are connected to
`the RAID 530 by using external hubs 510 and 520.
`FIG. 6 is a block diagram showing one embodiment of the
`host
`interface system as a network switch between the
`inventive RAID and host computers.
`As shown in the drawing, a plurality of host computers
`600, 601, 602, 604 and 605 are connected to RAID through
`a network switch 610. In other words, information from a
`second network interface controller 622 of a first RAID
`controller 620 is sent to a first network interface controller
`632 of a second RAID controller 630, and information from
`a second network interface controller 632 of the second
`RAID controller 630 is transmitted to a first network inter-
`face controller 621 of the first RAID controller 620. Further,
`information from the first network interface controller 631
`of the second RAID controller 630 is transmitted to the
`second network interface controller 622 of the first RAID
`controller 620. Also,
`information from the first network
`interface controller 621 of the first RAID controller 620 is
`sent to the second network interface controller 632 of the
`second RAID controller 630.
`Just,
`there is no distinction between respective ports,
`representatively 611, of a network switch 610 at all and also,
`the internal structure of a network switch 610 can be
`
`configured according to a selection of a user (not shown in
`FIG. 6).
`In accordance with the present invention, as afore-men-
`tioned, even in a case of an error occurrence in a RAID
`controller, there exist two independent networks and two
`network interface controllers, and the bandwidth of a single
`network can be twice maintained. Accordingly, a function of
`fault tolerance between two RAID controllers can be con-
`
`structed without a drop of the bandwidth.
`It will be apparent to those skilled in the art that various
`modifications and variations can be made in the present
`
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`US 6,978,346 B2
`
`6
`ports being provided as a network switch equipment con-
`nected with the numerous host computers.
`7. The apparatus as recited in claim 1, wherein said
`plurality of connecting units have at least five connection
`ports, four of the at least five connection ports is coupled to
`one of the first network interface controlling unit and the
`third network controlling unit and the rest of the connection
`ports being provided as a switch connected with the numer-
`ous host computers.
`8. The apparatus as recited in claim 1, wherein the first
`network interface controlling unit of the first RAID control-
`ling unit being connected to a first connecting unit, the
`second network interface controlling unit of said first RAID
`controlling unit being connected to a second connecting
`unit,
`the third network interface controlling unit of the
`second RAID controlling unit being connected to the second
`connecting unit, and the fourth network interface controlling
`unit of the second RAID controlling unit being connected to
`the first connecting unit.
`9. An apparatus for a redundant interconnection between
`multiple host computers and a RAID, the apparatus com-
`prising:
`a plurality of connection units for connecting the host
`computers and the RAID;
`a first and a second RAID controllers, included in the
`RAID, each of which having a first network interface
`controller and a second network interface controller for
`
`processing requests from the plurality of the host
`computers connected through the plurality of the con-
`nection units,
`wherein the first network interface controller in the first
`
`RAID controller supplies data to the host computers
`connected through the plurality of connection units and
`processes information transmitted from the second net-
`work interface controller in the second RAID control-
`ler,
`whereii the first network interface controller in the sec-
`
`5
`invention without deviating from the spirit or scope of the
`invention. Thus,
`it is intended that the present invention
`cover the modifications and variations of this invention
`
`provided they come within the scope of the appended claims
`and their equivalents.
`What is claimed is:
`
`1. An apparatus for a redundant interconnection between
`multiple hosts and a RAID, comprising:
`a first RAID controlling units and a second RAID con-
`trolling unit for processing a requirement of numerous
`host computers, the first RAID controlling unit includ-
`ing a first network controlling unit and a second net-
`work controlling unit, and the second RAID controlling
`unit including a third network controlling unit and a
`fourth network controlling unit; and
`a plurality of connection units for connecting the first
`RAID controlling units and the second RAID control-
`ling unit to the numerous host computers, wherein the
`first RAID controlling unit and the second RAID
`controlling unit directly exchange information with the
`numerous host computers through the plurality of con-
`necting units, and the first network controlling unit
`exchanges information with the fourth network con-
`trolling unit, and the second network controlling unit
`exchanges information with the third network control-
`ling unit.
`2. The apparatus as recited in claim 1, wherein said
`respective RAID controlling units are connected to the
`plurality of individual connecting units.
`3. The apparatus as recited in claim 2, wherein the first
`network interface controlling unit is coupled to the connect-
`ing unit of one side and the second network interface
`controlling unit is coupled to the connecting unit of another
`side.
`4. The apparatus as recited in claim 3, wherein
`the first network interface controlling unit and the third
`network interface controlling unit process the require-
`ment of the numerous host computers; and
`the second network interface controlling unit and the
`fourth network controlling unit are used for communi-
`cation between the first RAID controlling unit and the
`second RAID controlling unit when the first and second
`RAID controlling units are not faulty and the second
`network interface controlling unit and the fourth net-
`work controlling unit are used for executing a function
`of the first network interface controlling unit and the
`third network controlling unit when one of the first
`RAID controlling unit and the second RAID control-
`ling unit is faulty.
`5. The apparatus as recited in claim 1, wherein said
`plurality of connecting units have at least three connection
`ports, two of the at least three connection ports is coupled to
`one of the first network interface controlling unit and the
`third network controlling unit and the rest of the connection
`ports being provided as a hub equipment connected with the
`numerous host computers.
`6. The apparatus as recited in claim 1, wherein said
`plurality of connecting units have at least three connection
`ports, two of the at least three connection port are coupled
`to one of the first network interface controlling unit and the
`third network controlling unit and the rest of the connection
`
`10
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`15
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`20
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`25
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`30
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`40
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`45
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`60
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`
`ond RAID controller supplies data to the host comput-
`ers connected through the plurality of connection units
`and 3rocesses information transmitted from the second
`network interface controller in the first RAID control-
`ler,
`whereii the second network interface controller in the
`
`first RAID controller is used for fault tolerance by
`performing functions of the first network interface
`cont oller in the second RAID controller when the
`
`second RAID controller is faulty, and
`whereii the second network interface controller in the
`
`second RAID controller is used for fault tolerance by
`performing functions of the first network interface
`cont oller in the first RAID controller when the first
`
`RAID controller is faulty, and
`in the first
`whereii the first network controlling unit
`RAID controlling unit exchanges information with the
`second network controlling unit in the second RAID
`cont olling unit, and the second network controlling
`unit in the first RAID controlling unit exchanges infor-
`mation with the first network controlling unit in the
`second RAID controlling unit.
`*
`*
`*
`*
`
`*
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`VMWARE-1001 / Page 10 of 10
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`VMWARE-1001 / Page 10 of 10
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