Title: Data bank providing connectivity among multiple mass storage media devices using daisy chained universal bus interface
Abstract: A data storage system that houses at least two mass storage devices in an enclosure, along with all interconnect cabling electronics to permit access through a shared universal-type interface. An enclosure houses multiple mass storage devices such as disk drives. A set of bridges located within the enclosure provides connectivity from the disk interface to the universal-type bus. Bridge outputs are coupled to a universal hub also located within the enclosure to provide a single port interface to the array of disks. The arrangement thus provides for connectivity to multiple mass storage devices housing in a single enclosure with a single universal bus interface.
Patent Number: 6,875,023 Issued on 04/05/2005 to Brown
| Inventors:
|
Brown; Donald L. (Holliston, MA)
|
| Assignee:
|
Interactive Media Corporation (Millis, MA)
|
| Appl. No.:
|
187254 |
| Filed:
|
June 27, 2002 |
| Current U.S. Class: |
439/61; 710/74 |
| Intern'l Class: |
H01R 009//09; H01R 012//02 |
| Field of Search: |
439/61,79
361/786,788,789,686
709/208
710/36,74,129
|
References Cited [Referenced By]
U.S. Patent Documents
| 4883429 | Nov., 1989 | Suzuki et al. | 439/74.
|
| 5873738 | Feb., 1999 | Shimada et al. | 439/61.
|
| 5967796 | Oct., 1999 | Hartfiel et al. | 439/61.
|
| 5994894 | Nov., 1999 | Fujita | 324/158.
|
| 6098120 | Aug., 2000 | Yaotani | 710/16.
|
| 6763402 | Jul., 2004 | Talati | 710/36.
|
| 2001/0013079 | Aug., 2001 | Luke et al. | 710/129.
|
| 2002/0067593 | Jun., 2002 | Milan | 361/686.
|
| 2002/0078161 | Jun., 2002 | Cheng | 709/208.
|
| 2002/0081873 | Jun., 2002 | Harris et al. | 439/79.
|
Other References
UDMA133 MobileRACK SuperRACK [online], ViPowER, Inc. [Retrieved on Jan. 28,
2003]. Retrieved from the Internet <http://www.vipower.com/>.
Network-Attached Storage White Paper [online], The Role of Network Attached
Storage in the New Enterprise, Copyright Storage Computer Corporation
10/01, [Retrieved on Jan. 28, 2003]. Retrieved from the Internet
<http://www.sun.com/storage/white-papers/nas.html>.
Ultra2 SCSI White Paper, LinFinity Microelectronics, Rev. 1.0, 5/96,
<www.linifinity.com>.
|
Primary Examiner: Zarroli; Michael C.
Attorney, Agent or Firm: Hamilton, Brook, Smith & Reynolds, P.C.
Claims
What is claimed is:
1. A data storage system comprising:
an enclosure;
an accommodation for locating a plurality of mass storage devices within
the enclosure, the mass storage devices each having a corresponding device
interface;
at least two bridge devices also located within the same enclosure, the
bridge devices arranged to receive signaling from corresponding ones of
the device interfaces, each bridge converting the storage device interface
signaling to universal bus signaling, the bridge device also providing a
pair of universal bus port connections to permit access to the storage
device;
interconnecting a universal serial bus port associated with at least a
selected first one of the storage devices with at least a second one of
the storage devices; and
using one of the remaining universal serial bus port connections as a
common interface to access at least a first and second storage device of
the plurality of mass storage devices.
2. An apparatus as in claim 1 wherein multiple bridge devices are each
located on a support structure that has a generally facing relationship
with the rear portion of the storage devices to permit interconnection of
cables between the storage device interfaces and the bridges.
3. An apparatus as in claim 2 wherein the storage device accommodations are
generally located in approximately stacked vertical orientation with
respect to one another.
4. An apparatus as in claim 1 wherein a hub unit is located within the same
enclosure as the bridge devices to provide access to other devices located
within the same enclosure.
5. An apparatus as in claim 4 wherein the hub unit is located external to
the enclosure.
6. An apparatus as in claim 1 wherein the device interfaces are an
Integrated Device Electronics (IDE)/Advanced Technology Attachment
(ATA)-type interface.
7. An apparatus as in claim 1 wherein the universal bus is a Universal
Serial Bus-type 2 interface.
8. An apparatus as in claim 1 wherein the universal bus is a Fire Wire bus.
9. An apparatus as in claim 1 wherein the storage media is a removable
media drive.
Description
BACKGROUND OF THE INVENTION
The history of computing architectures is one of exceptional and rapid
advance. Indeed, the development of ubiquitous, flexible, low cost
computing platforms is arguably one of the most important engineering
feats of the last thirty years. It has also fundamentally changed the way
in which many organizations operate.
Particular developments in communications technology over the last several
years have produced an environment where many people require access to
information in various forms stored in computing systems. Indeed, the need
to efficiently store the virtual torrents of information that move in and
out of today's business computing systems was not expected when the first
computing systems and certainly the first low cost personal computer
systems were first placed on the desk top.
Initially, computing system architectures for the desktop required only
enough local storage capacity for application programs and data generated
by individuals. A direct-attached architecture whereby storage devices
such as Hard Disk Drives (HDDs) were directly connected to internal
computing system such as the Advanced Technology (AT) bus was quite
adequate for these needs. Organization and their information technology
departments later found it advantageous to adopt a client server model
where centralized server processors manage access to relatively large
centralized storage arrays. This architecture continues to use the
direct-attached storage model. To achieve higher performance, most servers
attached multiple HDDs using a high speed bus such as Small Computer
System Interface (SCSI). The SCSI interface requires a host adapter
circuit board to connect to a PC, but as a single SCSI adapter can manage
up to eight units or "identifiers." Since the host adapter uses one of
these identifiers, seven other identifiers may be used for additional
hardware peripherals such as Hard Disk Drives, tape drives, CD-ROMs,
scanners, and the like.
Despite the development of a higher speed SCSI-2 interface in the 1990s,
the most widely used interface between a storage device and the processor
is still the so-called "Integrated Device Electronics (IDE), or more
properly the AT Attachment (or ATA)-type interface. ATA type disk drives
have the drive controller built into them. They simply plug into a
connector on a PC motherboard or to an AT interface adapter card. Such
drives are thus quite easy to install and require a minimum number of
cables given that the controller is located on the drive itself.
Because the proper controller is integrated with the disk drive itself,
ATA/IDE drives are much easier for system manufacturers to configure. This
has been perhaps a downfall of the SCSI interface which lacks a standard
controller interface. In particular, each device's PC manufacturer seems
to have its own idea of how the SCSI interface should work. While the
physical connections themselves have been standardized, actual driver
specifications used for communication among devices has not. The end
result is that each bit of SCSI hardware typically requires its own host
adapter, and the software drivers for that device typically are
incompatible with adapters and drives made by other manufacturers. Because
of these aforementioned difficulties, it can be cumbersome to configure
arrays of SCSI based storage devices to work well with a variety of
different computing platforms.
Certain other devices, such as the Kanguru.TM. family of storage products
available from Interactive Media Corporation, provide a device that is a
removable hard disk having an interface that permits it to be used both as
an internal and external device. This device can provide some flexibility
in making data available to multiple users and locations.
The evolution of demands on direct-attached storage architectures has also
resulted in the development of additional storage initiatives. Thanks in
large part to increasing use of the Internet, data is created,
transmitted, stored and delivered in numerous places in an organization's
computing environment. Businesses need to meet skyrocketing storage needs
without an exponential increase in the required information technology
personnel support and/or equipment costs.
Network Attached Storage (NAS) is yet another solution to the storage
problem. This concept allows for shared use storage device that is
connected to a computer network. An NAS device is typically a dedicated,
high performance, high speed computing device that is optimized to stand
alone and serve specific storage access needs. Its file systems are
typically compatible with networking protocols such as Microsoft
Windows.TM. environments, FTP, HTTP, and the like. The idea basically is
to provide a file server having network protocol capability. This permits
any other machine also connected to the network to access files and other
information stored on the network attached drives.
However, even with network attached storage, there are performance
penalties given that data to be transferred must be packaged according to
network protocols. The networking devices themselves have inherent speed
limitations as compared to directly attached storage architectures.
In addition, network attached disks can require Information Technology
personnel to set up network protocols. It would be preferred if a simply
plug and play-type universal interface could be used.
SUMMARY OF THE INVENTION
What is needed is a way to connect a large number of data storage devices
without the need for using special adapters, local processors, or even
network interfaces. This would permit an associated server processor,
personal computer, or other computing device to serve as the access point
to the data device while freeing the data device itself to provide for
interconnectivity among media storage devices itself.
Such a storage system should also avoid the use of internal interfaces such
as the SCSI interface that require adapters that are somewhat difficult to
configure and indeed incompatible among different PC and storage
peripheral venders.
The present invention is a data storage system that provides the ability to
connect one or more mass storage devices such as Hard Disk Drives (HDDs),
CD-ROMs, Digital Video Disks (DVD) Compact Disk/Read Write (DC/RW), or the
like. Each mass storage device has a corresponding storage device
interface, such as an Integrated Device Electronics/Advanced Technology
Attachment (IDE/ATA) interface, serial ATA, solid state storage, filer
channel, or the like. Disk interface signaling is fed to a bridging device
to convert the storage device interface signaling to a more general
purpose, device independent external bus interface. Such a bridge, for
example, may convert the IDE/ATA signaling to Universal Serial Bus (USB),
Version 2 (USB2) interface. Other external universal buses interfaces such
as the so-called Fire Wire-type bus may also be appropriate. What is
important is that the bus use low cost IDE mechanisms and provide for
inherent expanded connectivity among devices. This allows individual
storage devices to be independently connected to a single external
controller such as a bus controller in a computer system that is external
to the enclosure in which the storage devices are housed.
In a preferred embodiment, connections among multiple mass storage devices
located within the enclosure are made by daisy-chaining the bus interface
connections. Specifically, each bridging device may itself include a pair
of Universal interface ports. The interface ports on each bridging device
are connected together. Thus, to connect multiple storage devices, cabling
is used to connect the interface port on a bridge serving one of the
storage devices to an interface port located on a bridge serving another
interface device. A single, common output port is then provided for the
storage array.
The USB and Fire Wire interfaces are examples of interfaces that are
intended for external computer peripheral connectivity by using high
speed, low cost serial-type bus connections. In one dependent aspect of
the invention, these universal interfaces can further each use hubs to
bring expanded connectivity among many devices while allowing individual
devices to be independently addressable by an external controller.
In other dependent aspects, the storage media may be versatile, removable
drives that can be used as both internal and external disks such as the
Kanguru.TM. products previously mentioned.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the invention
will be apparent from the following more particular description of
preferred embodiments of the invention, as illustrated in the accompanying
drawings in which like reference characters refer to the same parts
throughout the different views. The drawings are not necessarily to scale,
emphasis instead being placed upon illustrating the principles of the
invention.
FIG. 1 is an isometric view of a storage system constructed in accordance
with the invention.
FIG. 2 is a partial internal view of the storage system showing the storage
device, bridge, and internal hub connections.
FIG. 3 is an alternative arrangement for the bridge interfaces.
FIG. 4 is a more detailed view of a bridge.
FIG. 5 is a close up view of the connection between bridges.
FIG. 6 is an electrical block diagram of the storage system.
DETAILED DESCRIPTION OF THE INVENTION
A description of preferred embodiments of the invention follows.
FIG. 1 is an illustration of a storage unit constructed in accordance with
the invention. The unit includes an enclosure 10 that houses multiple mass
storage devices 12-1, 12-2, . . . , 12-n that fit into device brackets 14.
External interfaces to the unit 10 may be quite minimal, including only,
for example, a power connection 17 and single universal interface
connector 18. The storage unit thus provides a low cost, convenient,
storage capability that may be interfaced to a large number and variety of
computing devices through the single interface 18.
The brackets 14 each provide mechanical and electrical accommodation for
use of the mass storage devices 12.
More particularly, the enclosure 10 may take the form factor of a typical
tower-type personal computer enclosure. Within the enclosure 10, there is,
of course, a power supply 11 that receives electrical power through the
connector 17.
The individual storage devices 12 may be any convenient and/or required
storage device that has, for example, a standard form factor that can fit
into the tower-type enclosure 10. These, for example, may include Hard
Disk Drives (HDDs), Compact Disk/Read-Only Memory (CD/ROM) drives, CD
Read-Writable (CD/RW) drives, or other mass storage devices.
The drives 12 may also be a type of versatile removable drive such as the
Kanguru.TM. products available from Interactive Media Corporation of
Ashland, Mass., who is the assignee of the present invention. A Kanguru
Disk.TM. drive provides both internal and external hard disk
functionality. A Kanguru Disk.TM., for example, provides a mounting
bracket 14 for a connection that allows a removable media package to be
inserted into the housing 10. The connection provides data and power
signals to the disk drive. The media can also be removed and attached
through a separate interface to portable computing equipment, such as a
laptop computer, as desired. When used internally, the Kanguru Disk.TM.
offers fast data transfer speeds according to industry standards. When
used externally, it can provide a portable platform for transporting
essential data between locations. Although this invention would work with
internal fixed storage devices, the removable Kanguru Disk.TM. offers
additional connections, ease of use, and flexibility.
FIG. 2 is a more detailed view of the invention showing the interior of the
enclosure 10. An exemplary one 12-1 of the storage devices has an
interface connector 15 to which are connected a pair of ribbon cables 24-1
and 26-1. The first one of the ribbon cables 24-1 provides the electrical
signals that allow for external connection and control of data to and from
the storage device 12-1. The ribbon cable 24-1, for example, may be
configured according to the IDE/ATA-type standard interface. Other
interfaces would include serial ATA or the like. Please note that although
there is shown in FIG. 2 only a single storage device 12-1, it should be
understood that similar ribbon cable connections are made for the other
storage devices 12-2, . . . , 12-n.
The other ribbon cable 26-1 from each device 12 connects to the power
supply 11 to provide electrical power.
The ribbon cable 24-1 containing the data signals is connected to a bridge
device, or simply, bridge 20-1. There is a bridge 20-1, 20-2, . . . , 20-n
associated with each of the storage devices 12-1, 12-2, . . . , 12-n
placed within the enclosure 10. It should be understood that a single
bridge board could be used if it supports multiple connections.
The bridges 20 are mounted on an internal support structure 22. Bridge
structure 22 may be a set of mounting rails in the case where the bridges
20 are each a single printed circuit board. It should be understood,
however, that the support 22 may be itself a single printed circuit board
on which are formed multiple bridge 20 circuits.
Each bridge board 20 includes a pair of interface port connectors 38-1,
38-2. Each interface port connector 38 provides an interface connection,
such as a USB2 type connection to the respective bridge board 20. The
bridge board not only provides conversion of the ATA/IDE type signals from
the disk drive to USB2 format, but also serves as a small 2-port USB2 hub,
such that the two ports 38-1 and 38-2 provide the ability to daisy-chain
multiple storage units 12, so that they may be access through a single
output put. This daisy-chain type interconnection of storage units will be
described in greater detail below.
In accordance with one optional arrangement, a separate hub 30 may be
included within the enclosure to permits interconnection of signals from
the various other devices internal to the enclosure 10. The hub 30 may,
for example, be a hub that provides for a number of bridged connections to
be shared through the single shared output port 34. In the illustrated
embodiment, there are the hub 30 is a 4-port hub having 4 ports 32-1
through 32-4.
Please note significantly that there is no electrical componentry required
within the housing 10 with the exception of the bridge boards 20 and hub
30. Thus, for example, no central processing unit, disk controller
interface, adapter, network card, or other devices required within the
enclosure. Simply, connectivity to any of the storage devices 12 is
provided through a single port to the expediency of having the enclosed
hub 30 and bridge boards 20 individually allow connections to respective
ones of the disks through a star-type serial interface.
FIG. 3 is another similar view showing an alternate arrangement for
mounting the bridge boards 20. In this particular embodiment, the bridge
boards are oriented in a relative vertical orientation. It should be
understood that these may be mounted again in a similar fashion, in this
case, the circuit board 23 being the preferred means of such support.
FIG. 4 is a more detailed view of one of the bridge boards 20. Bridge board
20 contains a ribbon cable connector 40, mounting holes 42, electrical
components 44 and 46 are mounted on a printed circuit board 47. Also
mounted to the bridge board 20, in this case on the side of the board
opposite from the ribbon cable connector 40, is an interface connector 38.
In the illustrated preferred embodiment, the bridge board 20 is a IDE to
Universal Serial Bus Version 2 (USB2)-type bridge board providing
interconnectivity between the USB2-type signals provided on each of the
connectors 38-1 and 38-2 to IDE-type signals provided on the ribbon cable
connector 40. This connectivity is provided through an integrated circuit
44 and associated electrical components 46 mounted on the PCB 47. Other
circuits on the board operate as a hub, to provide for the interconnection
of external USB2 devices to either port 38-1 or 38-2.
Mounting holes 42 permit mechanical mounting of the bridge board 20 to
support structure 22 or 23 as in FIG. 2 or FIG. 3 respectively.
Also note that in the case of either the FIG. 2 or FIG. 3 arrangement, the
support structure 22 or 23 generally disposed in an orientation which is
facing the back end of the bank of storage devices 12, in a general
vertical orientation within the enclosure 10. This permits the ribbon
cables 24 to be exactly interconnected between the connectors 15 and 40.
FIG. 5 is another view of the support structure 23 for the bridge boards 20
showing the daisy chain interconnection in more detail. In particular, an
exemplary one of the bridge boards 20-1 provides signal connections
through one of its USB receptacles 38-2 a receptacle 38-1 located on an
adjacent bridge board 20-2, via a USB cable 50-1 containing USB plugs 52-1
and 54-1 on respective ends thereof. Specifically, a first plug 52-1 of
the cable 50-1 is inserted into port 38-2 of the first bridge board 20-1,
and the second plug 54-1 is inserted into a port 38-1 of the second bridge
board 20-2. Additional cables 50-2 and 50-n are then used to interconnect
the other ports 38-1 and 38-2 in this daisy chain arrangement.
The ports 38-1, 38-2 are connected as thru-ports by circuits on the bridge
board. Techniques are known for this connection, such as for Fire Wire
Interfaces, similar circuit techniques can be used to provide USB2 thru
ports. Alternately, the bridge board can act as a small two port hub.
A final cable 58 provides access to all of the daisy chained storage units
through a single USB2 connection. Although not shown in FIG. 5, this final
cable 60 may be connected to an output port 18 on the enclosure.
Alternatively, the final cable 58 may be connected to a port on a hub unit
30. In this embodiment, an additional cable 60 with plug ends 62 and 64
provides connectivity from the shared port 34 output of the hub 30 to the
external connection 18. Thus, through a single connection 18 by the
expediency of the hub 30, cable 6050 and bridge boards 20 many of the
individual storage units 12 and any other USB3 devices located in the
enclosure can be individually addressed.
FIG. 6 is an electrical block diagram of the storage system. The enclosure
10 has encased within it the mass storage devices 12-1, 12-2, . . . , 12n,
each communicating signals through respective IDE interfaces 15-1, 15-2, .
. . , 15-n. Power connections are also provided to the power supply for
each of the mass storage devices 12. The IDE signals 15 are fed to
respective ones of the IDE/USB2 bridges 20-1, 20-2, . . . , 20-n, which in
turn are connected in a daisy chain arrangement with the internal USB
cables 50-1, 50-2, . . . , 50-n. Finally, the output cable 60 provides
connectivity to all of the storage units 12 through the single plug 18 as
a USB2 addressable unit.
Alternatively, an internal hub 30 may receive the final cable 60, so that
other devices located in the enclosure 10 may also be accessed through the
single interface port 18.
Thus, the entire array of mass storage devices 12 appears as a single USB
unit which then itself can be connected to other USB2 hubs 70 that may be
external to the enclosure 10. This allows the host 80 to provide
connectivity to printers 74 and other peripheral devices, as well as the
storage unit 10, all controlled via the single UBS connection.
It should be understood that while what is shown in an arrangement where
discrete USB2 port sockets and cables having plug ends are used to daisy
chain the bridge board, that in other embodiments, the USB2 signals could
be carried on a printed circuit board 22 which comprises the bridge boards
20.
While this invention has been particularly shown and described with
references to preferred embodiments thereof, it will be understood by
those skilled in the art that various changes in form and details may be
made therein without departing from the scope of the invention encompassed
by the appended claims.
*
