Method and apparatus for sharing peripheral devices over a network

Abstract

Disclosed is a system for transparently sharing peripheral devices over a network. The system includes a first computer having at least one peripheral device, and a second computer that is networked to the first computer. The second computer is configured to send a request to use the at least one peripheral device over the network, and the request is processed to determine whether the second computer has sharing privileges to use the at least one peripheral device. Furthermore, the first computer is configured to grant access to the request of the second computer if the second computer has the sharing privileges that enable access to the at least one peripheral device. In this embodiment, the first computer acts as a Server that can share its peripheral devices, and the second computer acts as a Client that access the Server's peripheral devices.

Claims

What is claimed is:

1. An apparatus for sharing peripheral devices over a network, comprising:

a network of computers connected to the network;

a first computer connected to the network of computers, the first computer having a SCSI peripheral device connected thereto and having a first driver;

a second computer having a second driver, the second computer being connected to the network, the second computer being configured to communicate a SCSI command to use the SCSI peripheral device connected to the network of computers, the SCSI command being transmitted using a network protocol over the network between the second computer and the first computer to enable functional access of the SCSI peripheral device by the second computer as if the SCSI peripheral device were locally connected to the first computer.

2. An apparatus for sharing peripheral devices over a network as recited in claim 1, wherein each of the first driver and the second driver provide client/server functionality to enable sharing of the SCSI peripheral device.

3. An apparatus for sharing peripheral devices over a network as recited in claim 2, wherein the first driver and the second driver implement a send ASPI 32 command.

4. An apparatus for sharing peripheral devices over a network as recited in claim 2, wherein the first driver and the second driver implement a get ASPI 32 support info function to fund local host adapters in which a WNASPI32.DLL engine is executed, the local host adapters being connected to each of the first computer and the second computer.

5. An apparatus for sharing peripheral devices over a network as recited in claim 1, wherein the network protocol executed by each of the first computer and the second computer implements one of an IPX network protocol, a NetBEUI network protocol, a TCP/IP network protocol, and a Named Pipes network protocol.

6. An apparatus for sharing peripheral devices over a network, comprising:

a network of computers;

a first computer connected to the network of computers, the first computer having a SCSI peripheral device connected thereto;

a second computer connected to the network of computers, the second computer being configured to communicate a SCSI command to use the SCSI peripheral device connected to the network of computers, the SCSI command being transmitted over the network of computers between the second computer and the first computer to enable functional access of the SCSI peripheral device by the second computer as if the SCSI peripheral device were connected to the first computer.

7. An apparatus for sharing peripheral devices over a network as recited in claim 6, wherein the network of computers communicate using one of IPX, NetBEUI, TCP/IP, and Named Pipes network protocols.

8. An apparatus for sharing peripheral devices over a network as recited in claim 7, wherein one of the network protocols handles the transmission of the SCSI command.

9. An apparatus for sharing peripheral devices over a network as recited in claim 7, further comprising:

a first driver being run on the first computer;

a second driver being run on the second computer, the first driver being configured to enable communication of the SCSI command over the network of computers.

10. An apparatus for sharing peripheral devices over a network as recited in claim 9, wherein each of the first driver and the second driver provide client/server functionality to enable sharing of the SCSI peripheral device.

11. An apparatus for sharing peripheral devices over a network as recited in claim 9, wherein the first driver and the second driver implement a send ASPI 32 command.

12. An apparatus for sharing peripheral devices over a network as recited in claim 9, wherein the first driver and the second driver implement a get ASPI 32 support info function to fund local host adapters in which a WNASPI32.DLL engine is executed.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to computer peripheral devices, and more particularly to methods and apparatus for sharing peripheral devices connected to one networked computer with other networked computers.

2. Description of the Related Art

Recently, computer users have enjoyed substantial flexibility in the way their computers are equipped. This flexibility is primarily due to the increased use of peripheral devices, which allow computer users to purchase only those hardware devices that make sense for their particular work requirements. In fact, the variety of available peripheral devices is ever increasing, which necessarily requires that they be well integrated with the computer's existing software. Although most peripheral device manufactures are able to provide excellent software drivers that enable the full functionality of the peripheral devices when they are connected to a local computer, other networked computers are not always able to fully access or utilize the peripheral devices connected to other computers on a shared network.

FIG. 1 is a network diagram 10 having a number of computers 12a through 12d coupled together via a file server 14. In this configuration, each of the computers may communicate with each other, as well as share and use information stored on the file server 14. Conventionally, each of the computers may have a host adapter that enables the computer to connect up to external peripheral devices. As shown, computer 12a has a host adapter 16a which is used to connect up to peripheral devices, such as a hard drive 22, and a JAZ.TM. drive 24. Generally, the host adapter 16a is in the form of an adapter card (or PCMCIA card for portable computers) that connects to the computer 12a via a PCI bus or the like.

Similarly, computer 12b has a host adapter 16b which enables computer 12b to communicate to a scanner 18 and an optical drive 20. Although these peripheral devices enable computers 12a and 12b to have extended use and functionality, these peripheral devices are generally not fully accessible to other computers that are connected to the network over the file server 14. For example, even though computers 12c and 12d may conventionally acquire some rudimentary read and write privileges to peripheral devices 20, 22, and 24, they are still not able to issue full standard SCSI commands to those peripheral devices.

Furthermore, neither computer 12a, 12c, nor 12d may gain access or functional use of the scanner 18 that is connected to the computer 12b. This is generally the case because many peripheral devices are not assigned drive letters during boot-up. Such devices generally include scanners, tape drives, CD-R drives, and other SCSI based peripheral devices. As a result, those peripheral devices may not be fully shared over a network of computers, which may necessitate the purchase of a redundant peripheral device (i.e., a scanner) for each local computer system.

Unfortunately, this will drive up the cost of a given network, and may be unsuitable for smaller businesses or home offices where low cost networking solutions are most needed. To partially alleviate this problem, some computer peripheral companies have introduced a solution that enables sharing of such peripheral devices over a network when additional custom hardware circuitry and software is provided. For example, Hewlett-Packard of Palo Alto, Calif., has a hardware solution that requires users to purchase a network box 26 having special hardware to assist in communicating with a host adapter 16c. The network box 26 is then connected to a scanner 28 that is custom designed to interface with a network box 26. In some cases, the network box 26 circuitry may be integrated directly into the scanner 28.

Once the scanner 28 has been connected to the file server 14 via the host adapter 16c, the scanner 28 may be shared by other computers that are networked through the file server 14. Although this sharing solution works well in some high-end networks, the cost of sharing peripheral devices, such as scanner 28 over a network may be prohibitively expensive compared to the cost of a conventional peripheral device. Consequently, the scanner 28 and network box 26 solution may not be cost effective for use in smaller networked arrangements or home office use.

In view of the foregoing, there is a need for a method and apparatus that enables networked computers to access peripheral devices that are connected to any one of the respective network computers, without the need for expensive interfacing hardware or custom peripheral devices.

SUMMARY OF THE INVENTION

Broadly speaking, the present invention fills these needs by providing a method and apparatus for efficiently communicating and sharing peripheral devices that may be connected to a computer that is networked with other computers that may desire the use of the networked peripheral devices. It should be appreciated that the present invention can be implemented in numerous ways, including as a process, an apparatus, a system, a device, a method, or a computer readable medium. Several inventive embodiments of the present invention are described below.

In one embodiment, a system for sharing peripheral devices over a network is disclosed. The system includes a first computer having at least one peripheral device, and a second computer that is networked to the first computer. The second computer is configured to send a request to use the at least one peripheral device over the network, and the request is processed to determine whether the second computer has sharing privileges to use the at least one peripheral device. Furthermore, the first computer is configured to grant access to the request of the second computer if the second computer has the sharing privileges that enable access to the at least one peripheral device. In this embodiment, the first computer acts as a Server that can share its peripheral devices, and the second computer acts as a Client that access the Server's peripheral devices.

In another embodiment, a method for sharing peripheral devices over a network is disclosed. The network has a first computer that includes a first host adapter and a first SCSI peripheral device that is connected to the first host adapter. The method includes receiving a request to use the first SCSI peripheral device from a second computer that is connected to the network, and determining whether the second computer has access privileges to use the first SCSI peripheral device. The method further includes connecting the second computer to the first SCSI peripheral device if the second computer has access privileges to use the first SCSI peripheral device. Preferably, the method also includes determining whether a third computer is currently reserved to use the first SCSI peripheral device, and when the third computer is currently reserved to use the first SCSI peripheral device, the request to use the first SCSI peripheral device is placed in a queue.

In yet a further embodiment, an apparatus for sharing peripheral devices over a network that includes a first computer that has a first SCSI peripheral device is disclosed. The apparatus includes means for receiving a request to use the first SCSI peripheral device from a second computer that is connected to the network. Means for determining whether the second computer has access privileges to use the first SCSI peripheral device. The apparatus further includes means for connecting the second computer to the first SCSI peripheral device if the second computer has access privileges to use the first SCSI peripheral device. In this embodiment, the first computer acts as a server that can share the first SCSI peripheral device with the second computer that acts as a client.

Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, and like reference numerals designate like structural elements.

FIG. 1 is a network diagram that has a number of computers networked together.

FIG. 2A shows a network diagram in accordance with one embodiment of the present invention.

FIG. 2B shows a SCSI Explorer.TM. window that has an interrogator option in accordance with one embodiment of the present invention.

FIG. 2C shows a partial diagram of FIG. 2A, in which a Server/Client ScanLAN code is loaded onto computers in accordance with one embodiment of the present invention.

FIG. 2D shows the SCSI Explorer.TM. window after the ScanLAN code has been loaded onto some of the computers of FIG. 2A in accordance with one embodiment of the present invention.

FIG. 3A is a flowchart diagram illustrating the preferred method operations that may be used to access remote peripheral devices from a local computer system in accordance with one embodiment of the present invention.

FIG. 3B shows a computer screen shot of a ScanLAN Setup wizard for use in accordance with one embodiment of the present invention.

FIG. 3C shows a Server ScanLAN window that is displayed to the user when the Server ScanLAN application is run in accordance with one embodiment of the present invention.

FIG. 3D shows a properties computer screen shot that is used to modify sharing rights for Client's use of selected devices in accordance with one embodiment of the present invention.

FIG. 3E shows a properties window 360 in accordance with one embodiment the present invention.

FIGS. 3F and 3G show computer screen shots that may be used to modify sharing and use rights of particular Clients in accordance with one embodiment of the present invention.

FIG. 3H is a flowchart diagram illustrating the preferred method operations performed when a Client desires the use of a particular device that is connected to a Server in accordance with one embodiment of the present invention.

FIG. 4A shows a more detailed flowchart diagram of an operation of FIG. 3A, which describes the administering of Client privileges in accordance with one embodiment of the present invention.

FIG. 4B shows the properties window of FIG. 3E when an advanced button is selected in accordance with one embodiment of the present invention.

FIG. 5 shows a flowchart diagram that is a more detailed description of an operation of FIG. 3A in accordance with one embodiment of the present invention.

FIG. 6 is a block diagram of an exemplary computer system for carrying out the processing according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An invention is described for a method and apparatus for efficiently communicating and sharing peripheral devices that may be connected to a computer that is networked with other computers. It will be obvious, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present invention.

FIG. 2A shows a network diagram 110 in accordance with one embodiment of the present invention. In this example, computers 112a through 112d are networked via a file server 114. In addition, several of the computers have host adapters 116 which enable interconnection to external peripheral devices. As shown, computer 112a is connected to a hard drive 122 and a JAZ.TM. drive 124 via a host adapter 116a Computer 112b is connected to a scanner 118, an optical drive 120, and a hard drive 121 via a host adapter 116b. Computer 112d is connected to an optical drive 126 via a host adapter 116d1, and a hard drive 128, and a tape drive 130 via a host adapter 116d2.

In this example, computer 112c is not shown having an adapter for interconnecting external peripheral devices. In one embodiment, when a user of computer 112d wishes to verify which external peripheral devices it has access to, the user may perform a scan of host adapters and peripheral devices using a SCSI Explorer program, that is available from Adaptec, Inc. of Milpitas, Calif.

FIG. 2B shows a SCSI Explorer.TM. Window 202 that has an interrogator 204 option. When the interrogator 204 option is run, a list of available devices that are actually connected to computer 112d are shown in a window 206. Specifically, a SCSI device list in tree format is displayed identifying any devices that are accessible and connected to computer 112d of FIG. 2A. In this example, computer 112d is shown having a host adapter 116d1 and a host adapter 116d2, which respectively have the peripheral devices illustrated in FIG. 2A.

As shown, the SCSI Explorer.TM. Window 202 is not able to see or access any of the peripheral devices that are connected to the other computers that are networked via the file server 114 of FIG. 2A. Consequently, the user of computer 112d may not have full SCSI command access to the peripheral devices of either computer 112a or computer 112b. In one embodiment of the present invention, when a Server/Client (S/C) ScanLAN code is loaded onto any one of the computers that are networked in FIG. 2A, the code will enable a user of any one of those computers to see and access via full SCSI commands, peripheral devices on other computers. However, the access level may be restricted based on custom privilege settings, which will be described in greater detail below.

FIG. 2C shows a partial diagram of FIG. 2A in which the S/C ScanLAN code is loaded onto computer 112b and computer 112d in accordance with one embodiment of the present invention. In this embodiment, computers 112b and 112d may be any computer that is connected to a network (local area network, wide area network or Internet). In addition, the S/C ScanLAN code may be manually loaded onto each computer from a computer readable medium (i.e., diskettes, CD ROM, etc.) or remotely loaded onto selected computers over an administration network computer. Once the S/C ScanLAN code has been loaded onto individual computers, users of a selected networked computer will then be able to access the peripheral devices connected to other network computers as if the peripheral devices were connected to their local computer. As mentioned above, the access to selected peripheral devices of a given network may be custom modified to grant or deny use privileges.

By way of example, if the Server (S) ScanLAN code is loaded onto computer 112b, and the Client (C) ScanLAN code is loaded onto computer 112d, then the user of computer 112d may be granted access privileges to the peripheral devices connected to computer 112b (which runs as a Server). Alternatively, each one of computers 112b and 112d may be loaded with both the Server and the Client ScanLAN code, which will therefore enable other users connected to the network to access the peripheral devices connected to both computer 112b and computer 112d, when they are running as a Server.

A particular advantage of the present invention is that no additional hardware is needed to enable a user of a local computer to fully access the peripheral devices connected to other computers connected to the network. In fact, a user of a local computer may issue SCSI command to networked peripheral devices that would normally only work for peripheral devices that were connected to the local computer. As such, the user may now access devices, such as scanners, tape drives, CD-R drives, and other SCSI devices that are typically not assigned a drive letter, without the need for expensive hardware or expensive custom peripheral devices.

FIG. 2D shows the SCSI Explorer.TM. 202 window after the ScanLAN code has been loaded onto at least computers 112b and 112d of FIG. 2C in accordance with one embodiment of the present invention. As shown, the SCSI device list 206 is now expanded to include host adapter 116b (and peripheral devices 118, 120 and 121), which is physically connected to the computer 112b. Accordingly, when a user of the computer 112d uses the interrogator 204 to determine what peripheral devices and host adapters are connected to computer 112d, the SCSI device list 206 will also include the peripheral devices that are connected to computer 112b, as if they were physically connected to computer 112d. Advantageously, the user of computer 112d may now access and issue SCSI commands to those peripheral devices that are connected to the host adapter 112b as if they were connected to computer 112d.

In one embodiment, any computer that is running either the Server or the Client ScanLAN code, will also implement a modified Dynamically Linked Library (DLL). This modified DLL will therefore enable connection to remote host adapters when an Adaptec, Inc. WNASPI32.DLL (which ships with Microsoft's operating systems) sends requests to use devices over a network. For more information on the functionality of the modified DLL, reference may be made to commonly assigned application Ser. No. 09/005,792, filed on Jan. 12, 1998, now U.S. Pat. No. 6,101,555, the disclosure of which is incorporated herein by reference.

FIG. 3A is a flowchart diagram 300 illustrating the preferred method operations that may be used to access remote peripheral devices from a local computer system in accordance with one embodiment of the present invention. The method begins at an operation 302 where the Server/Client ScanLAN code is loaded onto at least a first computer and a second computer. Once the Server/Client ScanLAN code is loaded onto the first and second computer, the setting options of the Server and the Client ScanLAN program, may be modified at each one of the first and second computers.

It should be understood that the first and the second computers are merely two computers that are networked together over any network of computers. In addition, it is contemplated that any one of the networked computers may be loaded with either the Server or the Client ScanLAN code, or both the Server and the Client ScanLAN code, to enable access to the peripheral devices connected to each of the respective networked Server computers.

The method now proceeds to an operation 304 where the first computer is selected. By way of example, a user may have the second computer at a location that is remote from the first computer (e.g., another room, another cubical, another building or the like). When the first computer is selected, the method proceeds to a decision operation 306 where it is determined if the Server ScanLAN code was loaded onto the first computer. If the Server ScanLAN code was loaded onto the first computer, the method will proceed to an operation 310. In operation 310, the Server ScanLAN program is run on the first computer.

Generally speaking, the Server ScanLAN program may be run by selecting a Server ScanLAN icon from a list of programs that may be loaded onto the first computer. In one embodiment, the Server ScanLAN icon may be accessed by first selecting a START menu in a Windows 95/NT platform, and then selecting the Server ScanLAN icon from a list of programs that may be loaded on the first computer. Once the Server ScanLAN icon is selected and run in operation 310, the method will proceed to an operation 312 where the user may administer Client privileges (i.e., sharing options) to the peripheral devices connected to the first computer that, in this example, has the Server ScanLAN program running.

By way of example, if the first computer has the Server ScanLAN running, the user of the first computer (i.e., a Server) can grant use privileges on a per-peripheral device manner, so that clients connected to the first computer can share the peripheral devices. Generally speaking, the other users that are connected to the network should have the Client ScanLAN program loaded thereon to enable them to access the peripheral devices that are connected to the first computer, which is running the Server ScanLAN program.

In this manner, the user of the first computer may grant or deny access privileges to other computers (i.e., networked Clients), selected host adapters that are connected to the first computer, or to individual peripheral devices that are connected to their respective host adapters (that are connected to the first computer). This feature will be described in greater detail with reference to FIG. 3C below. Referring back to decision operation 306, if it is determined that the Server ScanLAN code was not loaded onto the first computer, the method will proceed to an operation 308.

In operation 308, the first computer is provided with use privileges of peripheral devices that are connected to a networked computer that has the Server ScanLAN code loaded thereon. For example, if any other computer over the network is running the Server ScanLAN program, those computers will be identified as available Server computers to the user of a Client ScanLAN program (if the Client is enabled to share SCSI peripheral devices across the network). The Client ScanLAN operation will be discussed in greater detail with respect to FIGS. 3D through 3G and FIG. 5 below.

Once the first computer is provided with the use privileges of the peripheral devices that are connected to the computers that have the Server ScanLAN code in operation 308, the method will end. Similarly, once the Client privileges are administered to the peripheral devices connected to a computer that has the Server ScanLAN code in operation 312 is complete, the method will also end. In one embodiment, device sharing rights may be set or modified as described in Table A below.

                             TABLE A
                      DEVICE SHARING RIGHTS
    DEFAULT SHARING RIGHTS: Default sharing rights are
    initially assigned during a first installation of the Server ScanLAN code.
    The installation wizards provide an interface to easily set these values.
    Note however, that these default sharing rights can also be modified any
    time the Server is running by right-clicking on the devices in the Server
    application window of FIG. 3C.
    PER-CLIENT SHARING RIGHTS: When a Client attaches to a
    Server for the first time, the Client is assigned the default sharing
     rights.
    The Server can then modify the Client's sharing rights to fit the needs of
    the individual Clients. This is done in the Server Scan LAN window of
    FIG. 3C by right-clicking on the Client name in the left hand pane of the
    server application. Another method for changing these values is to double-
    click on a Client name in the right-hand pane of the server application.
    This brings up the "Client Properties" page.
    HOST ADAPTER SHARING RIGHTS: If the sharing rights for a
    host adapter are set to "Not Shared", none of the devices connected to that
    host adapter will be available.

                             TABLE B
                   SENDING MESSAGES TO CLIENTS
    SHUTDOWN: When the Server is ready to shut down, it will
    preferably send a message to all Clients. It is then the responsibility of
     the
    Clients to detach from the Server.
    DEVICE IN USE: If a Client attempts to reserve a device which is
    already reserved by another Client, the Server will send a message to the
    Client letting it know the particular device requested is busy.

                             TABLE C
                        CLIENT MANAGEMENT
    LIST OF CLIENTS: The Server maintains a list of Clients that
    have attached to the Server. The Server is also responsible for maintaining
    the per-Client sharing rights of all Clients. This information is
     persistent
    and should be restored each time the Server is launched.
    ADD/DELETE CLIENTS: The Server can add and delete Clients
    at will. Newly added Clients will receive the default access rights. In one
    embodiment, any deleted Clients will not return in the Client list until
     the
    Client attempts to connect to the Server at a later time.
    PLUG-N-PLAY: When devices are added or removed via a plug
    and play mechanism, the Server will update itself appropriately.

                             TABLE D
                        DEVICE RESERVATION
    ONE AT A TIME: A device can only be reserved by one computer
    at a time. If the device is already reserved when another computer attempts
    to access the device, the Server sends a message to the Client who is
    trying to access the device informing them that the device is currently
    reserved by another Client.
    SERVER NEEDS TO RESERVE DEVICES: When the Server
    uses a device on their own system, the Server application knows this and
    will display the word "Server" in the "In Use" field of the left pane of
     the
    Server application window. No Clients will be allowed to access this
    device when the Server has it reserved. Therefore, the Server must also
    reserve a device in order to use it just like a remote Client. This
    functionality is very important when sharing devices. Although the server
    has the ability to remove a reservation on a device, it must be a conscious
    decision on the part of the Server user to remove a Client's reservation on
    a device. Otherwise, whenever the server desires to use a shared device on
    its system, it would bump a Client off, even if it was in the middle of
    performing a task.
    FREEING A DEVICE: If a device is reserved by a Client, the
    Server application can remove the Client's reservation status by right-
    clicking on the Client name who has the device reserved and selecting
    "Remove Reservation". This option will be disabled in the pop-up menu
    if the device is not currently reserved. If the Server has the device
    reserved, right-click on any Client name and select the "Remove
    Reservation" menu item to free the Server's reservation on a device.
    AUTO-RELEASE: Each device has a setting representing the
    amount of time (in minutes or the like) that this device may sit idle (no
    accesses) while currently reserved by a Client. If another Client is
     waiting
    to use the device and this time limit has been reached, the Server will
    automatically remove the reservation on the device and reserve the device
    in the name of the waiting Client. This feature can be enabled/disabled on
    a per-device basis as shown in FIG. 4B. Likewise, the time-out value can
    be set for each device. If no Client is waiting to use the device and the
    time limit is reached, the Server does not have to remove the reservation.
    AUTO-RESERVING: If the Server reserves a device for a Client as
    described above, the Server is then responsible for sending a message to
    the Client who just got the reservation to let it know it can now use
    the device.

• Inventors
  Goshey, Michael; McMahon, Maureen;
• Assignee
  Adaptec, Inc. (Milpitas, CA)
• Published
  Oct-29-2002
• Current US Classes:
  709/200
  709/202
  709/203
  709/220
  719/321
  719/326
  719/327
• Application #
  993447
• International Classes
  G06F 015/16
• Field of Search
  709/200-203 709/208 709/212-213 709/217-220 709/321-322 709/326-327
• Examiner
  Maung; Zarni
• Agent
  Martine & Penilla, LLP
• US Patent References:
  5548783
  5721880
  5901286
  5933259
  5961627
  5991829
  5996024
  6003065
  6101555
  6327613