In a system for appliance back-up, a primary appliance is coupled to a network, whereby the primary appliance receives requests or commands and sends a status message over the network to a standby appliance, which indicates that the primary appliance is operational. If the standby appliance does not receive the status message or the status message is invalid, the standby appliance writes a shutdown message to a storage device. The primary appliance then reads the shutdown message stored in the storage device and disables itself from processing requests or commands. When the primary appliance completes these tasks, it disables communication connections and writes a shutdown completion message to the storage device. The standby appliance reads the shutdown completion message from the storage device and initiates a start-up procedure. This procedure causes the address of the standby appliance to be identical to the primary appliance address, and the standby appliance processes the requests or commands in place of the primary appliance.
|
12. A method for appliance back-up comprising:
monitoring a primary appliance for an indication of a failure, the primary appliance having a primary appliance address,
wherein if the failure occurs:
writing a message to a storage device;
in response to the message, disabling the primary appliance from processing requests or commands;
causing a standby appliance address of a standby appliance to be identical to the primary appliance address; and
processing the requests or commands.
7. A method for appliance back-up comprising:
sending a status message from a primary appliance to a standby appliance indicating that the primary appliance is operational;
if the standby appliance does not receive the status message or the status message is invalid:
writing a shutdown message to a storage device;
reading the shutdown message stored in the storage device;
disabling the primary appliance from processing requests or commands;
causing a standby appliance address to be identical to a primary appliance address; and
causing the standby appliance to process the requests or commands.
0. 52. A system comprising
a first device configured to process requests or commands received from a network, via a first communications link, the first device having a first address; and
a second device configured to:
determine a status of the first device;
assume an emulation address including, at least in part, the first address, based, at least in part, on the determination;
cause the first device to disconnect itself from the network based, at least in part, on the determination;
determine a second status of the first device after the first device disconnects from the network; and
instruct the first device via a second communications link different from the first communications link, to connect itself to the network based, at least in part, on the second status.
1. A system for appliance back-up comprising:
a network;
a storage device coupled to the network; and
a primary appliance and a standby appliance coupled to the network, the primary appliance receiving requests or commands and sending a status message via the network to the standby appliance indicating that the primary appliance is operational,
wherein if the standby appliance does not receive the status message or the status message is invalid:
the standby appliance writes a shutdown message to a the storage device,
the primary appliance reads the shutdown message stored in the storage device and disables itself from processing requests or commands, and
the standby appliance causes a standby appliance address to be identical to a primary appliance address and processes the requests or commands.
0. 54. A method of operating a communications system comprising a first appliance to process requests or commands received from a network via a first communications link and a second appliance, the method comprising:
determining by a second appliance a status of a first appliance;
assuming by the second appliance an address associated with the first appliance, based, at least in part, on the status;
processing requests or commands addressed to the first appliance, by the second appliance, after assuming the address;
causing the first appliance to disconnect itself from the network based, at least in part, on the determination, by the second appliance;
determining by the second appliance a second status of the appliance after the first appliance is disconnected from the network; and
instructing the first appliance via a second communications link different from the first communications link, to begin a start-up procedure to resume reception and processing of requests or commands based, at least in part, on the second status, by the second appliance.
0. 65. A communications system, comprising:
at least one storage device;
a first appliance to receive requests or commands for communicating with one or more of the at least one storage devices, the first appliance having a first appliance address; and
a second appliance;
wherein the first appliance is configured to:
communicate with one or more of the at least one storage devices in response to a received request or command; and
provide an indication to the second appliance of a status of the first appliance; and
the second appliance is configured to:
determine a status of the first appliance based, at least in part, on the indication;
assume an emulation address comprising the first appliance address in order to receive the requests or commands addressed to the first appliance, based, at least in part, on the indication;
process the requests or commands addressed to the first appliance, after assuming the emulation address; and
write a message to one of the at least one storage devices to cause the first appliance to disable itself, based at least in part, on the indication.
0. 70. A communications system, comprising:
a network;
at least one storage device;
a first appliance coupled to the network, to receive requests or commands for communicating with one or more of the at least one storage devices, the first appliance having a first appliance address;
a second appliance coupled to the network; and
a communications link between the first appliance and the second appliance
wherein the first appliance is configured to:
communicate with one or more of the at least one storage devices, based, at least in part, on the requests or commands; and
provide an indication to the second appliance indicating a status of the first appliance; and
the second appliance is configured to:
determine a status of the first appliance, based, at least in part, on the indication;
assume an emulation address comprising the first appliance address to receive the requests or commands directed to the first appliance, based at least in part, on the indication;
process the requests or commands addressed to the first appliance after assuming the emulation address; and
writing a message to the storage device to cause the first appliance to disable itself from processing requests or commands, if the link is broken.
0. 44. A communications system, comprising:
a network;
at least one storage device;
a first appliance coupled to the network via a first communications link, to receive requests or commands for communicating with one or more of the at least one storage device, the first appliance having a first appliance address; and
a second appliance coupled to the network;
wherein the first appliance is configured to:
communicate with one or more of the at least one storage devices, based, at least in part, on the requests or commands; and
provide an indication to the second appliance indicating a status of the first appliance; and
the second appliance is configured to:
determine a status of the first appliance, based, at least in part, on the indication;
assume an emulation address comprising the first appliance address to receive the requests or commands directed to the first appliance, based at least in part, on the indication;
process the requests or commands addressed to the first appliance after assuming the emulation address;
cause the first appliance to disconnect itself from the network based at least in part, on the second status;
determine a second status of the first appliance after the first appliance is disconnected from the network; and
instruct the first appliance via a second communications link different from the first communications link, to connect itself to the network based, at least in part, on the second status.
0. 74. A communications system, comprising:
at least one storage device;
a first appliance having a first appliance address, the first appliance being configured to:
receive requests or commands for communicating with one or more of the at least one storage devices via a first communications link; and
a second appliance configured to:
transmit, at selected times, messages to the first appliance via a second communications link different from the first communications link; and
wherein:
the first appliance is further configured to:
communicate with one or more of the at least one storage devices in response to a received request or command;
in response to each message received from the second appliance, provide an indication to the second appliance of a status of the first appliance via the second communications link; and
inform the second appliance, via the second communications link, of a problem relating to an operation of the first appliance, if the first appliance detects a problem relating to the operation of the first appliance; and
the second appliance is further configured to:
assume an emulation address comprising the first appliance address in order to receive the requests or commands addressed to the first appliance, if informed of a problem relating to the operation of the first appliance;
process the requests or commands addressed to the first appliance, after assuming the emulation address; and
instruct the first appliance via the second communications link to begin a start-up procedure, if informed that the problem has been repaired.
0. 27. A communications system, comprising:
at least one storage device;
a first appliance configured to receive requests or commands for communicating with one or more of the at least one storage devices via a first communications link, the first appliance having a first appliance address; and
a second appliance configured to:
transmit, at selected times, messages to the first appliance via a second communications link different from the first communications link;
wherein:
the first appliance is further configured to:
communicate with one or more of the at least one storage devices in response to a received request or command; and
in response to each message received from the second appliance, provide an indication to the second appliance of a status of the first appliance via the second communications link; and
the second appliance is further configured to:
monitor the status of the first appliance based, at least in part, on the indications received from the first appliance;
determine whether a proper indication is received in response to each message;
assume an emulation address comprising the first appliance address in order to receive the requests or commands addressed to the first appliance, based, at least in part, on a failure to receive a proper indication;
process the requests or commands addressed to the first appliance, after assuming the emulation address;
continue to monitor the status of the first appliance, after assuming the emulation address;
if failure to receive a proper indication from the first appliance is due to a problem relating to the first appliance, determine that the problem has been resolved; and
transmit to the first appliance via the second communications link information directing the first appliance to resume receiving requests and commands directed to the first appliance address, when the second appliance determines that the problem has been resolved; and
the first appliance is further configured to resume receiving requests and commands directed to the first appliance address, in response to the information.
2. The system of
3. The system of
4. The system of
5. The system of
6. The system of
8. The method of
9. The method of
10. The method of
reading the shutdown completion message from the storage device; and
initiating a start-up procedure.
11. The method of
13. The method of
14. The method of
15. The method of
16. The method of
17. The method of
18. The method of
19. The method of
reading the shutdown completion message from the storage device; and
initiating a start-up procedure.
20. The method of
21. The method of
22. The method of
23. The method of
24. The method of
0. 25. The system of claim 1, wherein:
the standby appliance monitors the status of the primary appliance via a communications link; and
the standby appliance writes the shutdown message to the storage device if the communications link is broken.
0. 26. The method of claim 7, comprising writing the shutdown message to the storage device if a communications link between the standby appliance and the primary appliance is broken.
0. 28. The system of claim 27, wherein the indication comprises a message.
0. 29. The system of claim 27, wherein the indication comprises failure to receive the message.
0. 30. The system of claim 27, wherein the status relates to whether the first appliance is operational.
0. 31. The system of claim 27, wherein:
the first appliance and the second appliance communicate via a link.
0. 32. The system of claim 31, wherein:
the second appliance is configured to send a heartbeat to the first appliance, via the link; and
the first appliance is configured to send the indication in response to the heartbeat, via the link.
0. 33. The system of claim 27, wherein the second appliance is further configured to cause the first appliance to disable itself, based at least in part, on the indication.
0. 34. The system of claim 33, wherein:
the second appliance is configured to cause the first appliance to disable itself, by writing a message to one of the at least one storage devices.
0. 35. The system of claim 34, wherein:
the second appliance is configured to write the message to the storage device if a communications link between the second appliance and the first appliance fails.
0. 36. The system of claim 33, wherein:
the second appliance is configured to cause the first appliance to disable itself by informing the first appliance over the link.
0. 37. The system of claim 33, wherein:
the first appliance is configured to continue to provide an indication to the second appliance of the status of the first appliance after being disabled; and
the second appliance is further configured to:
instruct the first appliance to begin a start-up procedure, based, at least in part, on the indication, after disabling of the first appliance.
0. 38. The system of claim 27, wherein:
the first and second appliances are coupled to a network.
0. 39. The system of claim 27, wherein the second appliance stores information relating to the first address, before the second appliance determines that the first appliance is not operational.
0. 40. The system of claim 27, wherein the first and second appliance addresses comprise, at least in part, a worldwide port name.
0. 41. The system of claim 27, wherein the emulation address and the first appliance address are the same.
0. 42. The system of claim 27, wherein:
the first appliance comprises a first fibrechannel adapter having associated therewith the first appliance address; and
the second appliance comprises a second fibrechannel adapter having associated therewith the second appliance address.
0. 43. The communications system of claim 27, wherein the first appliance is further configured to:
continue to provide indications to the second appliance of the status of the first appliance; and
the second appliance is configured to determine that the problem has been resolved based, at least in part, on the indications.
0. 45. The system of claim 44, wherein:
the first appliance is configured to continue to provide an indication to the second appliance of the second status of the first appliance; and
the second appliance is further configured to:
instruct the first appliance to begin a start-up procedure to resume reception and processing of requests or commands, based, at least in part, on the indication.
0. 46. The system of claim 44, further comprising:
a communications link between the first appliance and the second appliance.
0. 47. The system of claim 46, wherein:
the second appliance is configured to send a heartbeat to the first appliance, via the link; and
the first appliance is configured to send the indication in response to the heartbeat, via the link.
0. 48. The system of claim 46, wherein the second appliance is configured to write a message to the storage device to cause the first appliance to disable itself, if the link is broken.
0. 49. The communications system of claim 44, wherein:
the first appliance is configured to provide the indication to the second appliance via the second communications link.
0. 50. The communications system of claim 49, wherein:
the second appliance causes the first appliance to disconnect itself from the network by instructing the first appliance via the second communications link.
0. 51. The communications system of claim 44, wherein:
the second appliance causes the first appliance to disconnect itself from the network by instructing the first appliance via the second communications link.
0. 53. The system of claim 52, wherein the second device is further figured to:
process requests or commands addressed to the first device, after assuming the emulation address.
0. 55. The method of claim 54, comprising:
assuming by the second appliance a same address as the first appliance.
0. 56. The method of claim 54, comprising:
determining the status of the first appliance based, at least in part, on an indication from the first appliance.
0. 57. The method of claim 54, wherein the indication comprises a message.
0. 58. The method of claim 54, wherein the indication comprises failure to receive a message.
0. 59. The method of claim 54, wherein:
the first appliance and the second appliance communicate via a link.
0. 60. The method of claim 59, further comprising:
sending a heartbeat between the first appliance and the second appliance, via the link;
sending an acknowledgement of the heartbeat between the first appliance and the second appliance; and
disabling the first appliance if either or both of the heartbeat or the acknowledgement are not received by the second appliance.
0. 61. The method of claim 59, further comprising:
detecting a break in the link; and
writing a message to a storage device to disable the first appliance, if a break in the link is detected.
0. 62. The method of claim 54, further comprising:
receiving by the second appliance a request or command addressed to the first appliance after the second appliance assumes the address; and
processing, by the second appliance, the request or command.
0. 63. The method system of claim 54, further comprising:
disabling the first appliance, based, at least in part on the indication.
0. 64. The method of claim 63, further comprising:
continuing to receive an indication of the status of the first appliance by the second appliance, after causing the first appliance to disconnect itself from the network.
0. 66. The system of claim 65, wherein:
the second appliance is configured to write the message to the storage device if a communications link between the second appliance and the first appliance fails.
0. 67. The communications system of claim 65, wherein:
the network comprises a fibrechannel network.
0. 68. The communications system of claim 67, wherein:
the first appliance includes a first fibrechannel adaptor having associated therewith the first appliance address; and
the second appliance includes a second fibrechannel adaptor having associated therewith the emulation address.
0. 69. The communications system of claim 68, wherein:
the first appliance address comprises a first world wide port name (“WWPN”).
0. 71. The communications system of claim 70, wherein:
the network comprises a fibrechannel network.
0. 72. The communications system of claim 71, wherein:
the first appliance includes a first fibrechannel adaptor having associated therewith the first appliance address; and
the second appliance includes a second fibrechannel adaptor having associated therewith the emulation address.
0. 73. The communications system of claim 72, wherein:
the first appliance address comprises a first world wide port name (“WWPN”).
0. 75. The communications system of claim 74, wherein:
the first appliance is further configured to inform the second appliance that the problem has been repaired.
0. 76. The communications system of claim 75, wherein:
the first appliance is further configured to inform the second appliance that the problem has been repaired, via the second communications link.
0. 77. The communications system of claim 74, wherein the second appliance is further configured to de-activate itself from receiving requests or commands addressed to the first appliance, after instructing the first appliance to begin the start-up procedure.
|
|||||||||||||||||||||||||||
This application is a continuation-in-part of U.S. patent application Ser. No. 09/792,873, filed Feb. 23, 2001 now abandoned, entitled “Storage Area Network Using A Data Communication Protocol,” and is also a continuation-in-part of U.S. patent application Ser. No. 09/925,976, filed Aug. 9, 2001 now U.S. Pat. No. 7,093,127, entitled “System And Method For Computer Storage Security,” the disclosures of which are incorporated herein by reference.
The present invention concerns “port spoofing,” which allows a computer to “fail over” to its secondary fibrechannel connection if its primary fibrechannel connection should fail.
Fibrechannel is a network and channel communication technology that supports high-speed transmission of data between two points and is capable of supporting many different protocols such as SCSI (Small Computer Systems Interface) and IP (Internet Protocol). Computers, storage devices and other devices must contain a fibrechannel controller or host adapter in order to communicate via fibrechannel. Unlike standard SCSI cables, which can not extend more than 25 meters, fibrechannel cables can extend up to 10 km. The extreme cable lengths allow devices to be placed far apart from each other, making it ideal for use in disaster recovery planning. Many companies use the technology to connect their mass storage and backup devices to their servers and workstations.
In addition to being able to protect data through disaster recovery plans and backup, another requirement for a computer data communications network is that the storage devices must always be available for data storage and retrieval. This requirement is called “High Availability.” High Availability is a computer system configuration implemented with hardware and software such that, if a device fails, another device or system that can duplicate the functionality of the failed device will come on-line to take its place automatically and transparently. Users will not be aware that a failure and switch-over had taken place if the system is implemented properly. Many companies cannot afford to have downtime on their computer systems for any length of time. High availability is used to ensure that their computer systems remain running continuously in the event of any device failure. Servers, storage devices, network switches and network connections are redundant and cross-connected to achieve High Availability.
In the configuration of
The present invention is a system and method of achieving High Availability on fibrechannel data paths between an appliance's fibrechannel switch and its storage device by employing a technique called “port spoofing.” This system and method do not require any proprietary software to be executing on the file/application appliance other than the software normally required on an appliance, which includes the operating system software, the applications, and the vendor-supplied driver to manage its fibrechannel host adapter(s).
The invention includes a system for appliance back-up, in which a primary appliance is coupled to a network, whereby the primary appliance receives requests or commands and sends a status message over the network to a standby appliance, which indicates that the primary appliance is operational. If the standby appliance does not receive the status message or the status message is invalid, the standby appliance writes a shutdown message to a storage device, which is also coupled to the network. The primary appliance then reads the shutdown message stored in the storage device and disables itself from processing requests or commands. Preferably, when the primary appliance completes these tasks, it disables communication connections and writes a shutdown completion message to the storage device. The standby appliance reads the shutdown completion message from the storage device and initiates a start-up procedure, which includes causing the address of the standby appliance to be identical to the primary appliance address and processing the requests or commands in place of the primary appliance. The primary appliance can include a fibrechannel adapter having associated therewith the primary appliance address, and the standby appliance can have a fibrechannel adapter having associated therewith the standby appliance address. The standby appliance can include a standby application, which is identical to a primary application in the primary appliance, for processing the requests or commands.
The invention also includes a method for appliance backup, which includes sending a status message from a primary appliance to a standby appliance indicating that the primary appliance is operational. If the standby appliance does not receive the status message or the status message is invalid, a shutdown message is written to a storage device. The primary appliance reads the shutdown message stored in the storage device and is disabled from processing requests or commands. The disabling of the primary appliance can include completing tasks, disabling communication connections, and writing a shutdown completion message to the storage device. The standby appliance reads the shutdown completion message from the storage device and initiates a start-up procedure so that a standby application, included in the standby appliance, can process the requests or commands. A standby appliance address is changed to the primary appliance address and the standby appliance processes the requests or commands.
Another method for appliance back-up is disclosed which includes monitoring a primary appliance for an indication of a failure, the primary appliance having a primary appliance address. If the failure occurs, a message is written to a storage device and, in response, the primary appliance is disabled from processing requests or commands. The failure can be the primary appliance not sending the status message to a standby appliance. The standby appliance has a standby appliance address, which is changed to the primary appliance address so the standby appliance can processes the requests or commands. The standby appliance address and the primary appliance address are world wide port names. The monitoring can include sending a status message to the standby appliance indicating that the primary appliance is operational, or sending a status request message to the primary appliance and receiving an update status message from the primary appliance. The failure message is written if the standby appliance does not receive the status message or if the status message is invalid. Alternatively, the message is written if the standby appliance does not receive the update status message or the update status message is invalid. The disabling can include completing tasks, disabling communication connections, writing a shutdown completion message to the storage device (by the primary appliance), reading the shutdown completion message from the storage device (by the standby appliance), and initiating a start-up procedure. The standby appliance can include a standby application, which is identical to a primary application in the primary appliance, for processing the requests or commands.
One of the primary advantages of the present invention is that additional software is not required to be running on the file/application server. Many system administrators prefer to only install the software that is necessary to run their file/application servers. Many other solutions require special software or drivers to run on the server in order to manage the fail-over procedure.
These and other features and advantages of the invention will be apparent to those skilled in the art from the following detailed description of preferred embodiments, taken together with the accompanying drawings, in which:
The present invention is based on a software platform that creates a storage area network (“SAN”) for file and application servers to access their data from a centralized location. A virtualized storage environment is created and file/application servers can access its data through a communication protocol such as Ethernet/IP, fibrechannel, or any other communication protocol that provides high-speed data transmissions. Fibrechannel is the protocol that will be discussed herein, although it is understood that the other previously mentioned communication protocols are also within the scope of the present invention.
As mentioned before, computers, storage devices and other devices contain a fibrechannel (FC) controller or host adapter in order to communicate via fibrechannel. In the present invention, FC hubs/switches are used to connect file/application servers to servers that manage the storage devices. Storage devices can be RAID (redundant array of independent disks) subsystems, JBODs Just a bunch of disks), or tape backup devices, for example. An FC switch allows a server with a fibrechannel host adapter to communicate with one or more fibrechannel devices. Without a hub or switch, only a point-to-point or direct connection can be created, allowing only one server to communicate with only one device. “Switch” thus refers to either a fibrechannel hub or switch.
Fibrechannel adapters are connected together by fiber or copper wire via their FC port(s). Each port is assigned a unique address called a WWPN or “world wide port name.” The WWPN is a unique 64-bit identifier assigned by the hardware manufacturer and is used to establish the source and destination between which data will travel. Therefore, when an FC device communicates with another FC device, the initiating FC device, or “originator,” must use the second FC device's WWPN to locate the device and establish the communication link.
Fibrechannel devices that are connected together by an FC switch communicate on a “fabric.” If a hub is employed, then the communication link is called a “loop.” On a fabric, devices receive the full bandwidth when they are communicating with each other, and on a loop the bandwidth is shared.
Although the manufacturers assign WWPN addresses, the addresses are not permanently fixed to the hardware. The addresses can be changed. Software can programmatically change the WWPN addresses on the fibrechannel hardware. The present invention employs this feature by changing the WWPN address on a standby FC adapter to the WWPN address used by the failed FC adapter.
The present invention employs storage management software that is capable of running within any kind of computing device that has at least one CPU and is running an operating system. Examples of such computing devices are an Intel®-based PC, a Sun® Microsystems Unix® server, an HP® Unix® server, an IBM® Unix® server or embedded systems (collectively referred to as “appliances”). The software performs the writing, reading, management and protection of data from its file/application servers and workstations, and is disclosed with more specificity in U.S. patent application Ser. No. 09/792,873, filed Feb. 23, 2001, the disclosure of which has already been expressly incorporated herein by reference. One of the protection features of the software is the ability to “fail over” to another appliance if a set of defined failures occurs. The failures are defined and discussed in the following paragraphs.
More specifically, the present invention creates a transparent secondary path for data to flow in the event that a primary data path to a storage device or storage server managing the primary path fails for any reason. The secondary path is a backup communication link to the same storage device. Each computer contains at least one FC host adapter connected to one FC switch. This operation is shown in
This standby appliance 530 can be implemented strictly as a fail-over appliance for one or more primary appliances. If its only function is to standby, then standby appliance 530 must wait for one of the primary appliances to fail so that it can become data active. If a standby appliance 530 is a fail-over appliance for more than one primary appliance 525, then it must contain one dedicated standby FC adapter 517 for each primary appliance 525, and it must have a dedicated connection to each storage device 550 that it might need to manage. Standby appliance 530 itself can also be a primary appliance to its own set of SAN clients and storage devices 550. The operations of being both a primary and standby appliance are multitasked.
Standby appliance 530 monitors the status or the “health” of its primary appliance 525 through a communications link called the health monitor link 535. Messages called “fail-over heartbeats” are sent from standby appliance 530 to primary appliance 525, and if the messages are properly acknowledged the status of primary appliance 525 is acceptable. A “heartbeat” system is disclosed with more specificity in U.S. patent application Ser. No. 09/925,976, filed Aug. 9, 2001, entitled “System And Method For Computer Storage Security,” the disclosure of which has already been expressly incorporated herein by reference. If the heartbeat is not properly acknowledged or not acknowledged at all, then standby appliance 530 will begin the procedure for taking over the tasks of primary appliance 525. The heartbeat can also be implemented such that the heartbeat is sent from primary appliance 525 to standby appliance 530; this simply is a choice based on the software's architecture and ease of implementation. If a standby appliance 530 is a fail-over appliance for multiple primaries, the communications link can be configured to be shared among all primary appliances 525 or one dedicated communications link can be connected from each primary appliance 525 to standby appliance 530. The communications link can be any type of medium or protocol such as, for example, an Ethernet IP connection, a fibrechannel connection or a serial connection. It is also possible that the health monitor can also function from standby FC adapter 517 along standby path 520 to monitor the status of the primary appliance.
The health monitor link 535 performs several tasks:
Standby appliance 530 also takes over its primary appliance's tasks if health monitor link 535 is broken or the heartbeat is not acknowledged. Health monitor link 535 may be broken due to a cut cable or “accidental” removal. The heartbeat may not be acknowledged because primary appliance 525 loses power, crashes, or incurs another similar event. Although a broken link 535 does not affect the ability of primary appliance 525 to perform its tasks, primary appliance 525 will be regarded as a failed appliance nonetheless, and standby appliance 530 will take steps to begin to take over the tasks from primary appliance 525. Since standby appliance cannot communicate to primary appliance 525 to shut itself down, a backup method is used to pass on the shutdown signal.
If primary appliance 605 initially becomes inoperative because of loss of power, system crash, or some other catastrophic event, standby appliance 610 writes its shutdown message to the common file 625 with the assumption that primary appliance 605 may still be active. Standby appliance 610 functions in this manner because it cannot be assumed that primary appliance 605 is totally inoperative. A predetermined time interval is given by standby appliance 610 for primary appliance 605 to respond to the shutdown message, and if the shutdown message is not acknowledged standby appliance 610 begins its procedures to become active to take over the tasks of the failed primary appliance 605. Standby appliance 610 monitors the common file 625 for the shutdown acknowledgement message, and as soon as this message is received standby appliance 610 waits for the shutdown completion message.
Blocks 720 through 760 detail the steps employed by standby appliance 610. At block 720, standby appliance 610 detects the lack of a response from the health monitor link. In step 725, standby appliance 610 next writes the shutdown message to common file 625. The program proceeds to blocks 730 and 740 to wait for a shutdown acknowledgment message from primary appliance 605. Block 730, which queries whether the shutdown acknowledgment message has been received from primary appliance 605. If the answer is “NO,” the program proceeds to decision block 740, which queries whether the predetermined time period has expired. If the answer at decision block 740 is “NO,” the program loops back to block 730. If the answer at decision block 740 is “YES,” the program proceeds to block 760 where standby appliance 610 begins procedures to become active and to take over the tasks of primary appliance 605. Returning to decision block 730, if the answer to the query is “YES,” the program proceeds to blocks 750 and 755 where standby appliance 610 waits for the shutdown completion message from primary appliance 605. In decision block 750, the program queries whether the shutdown completion message has been received from primary appliance 605. If the answer is “NO,” the program proceeds to decision block 755, which queries whether the predetermined time period has expired. If the answer at decision block 755 is “NO,” the program loops back to block 750. If the answer at decision block 755 is “YES,” the program proceeds to block 760 where standby appliance 610 begins procedures to become active and to take over the tasks of primary appliance 605. Returning to decision block 750, if the answer to the query is “YES,” the program again proceeds to decision block 760, as discussed immediately above.
After the shutdown completion message is received or after the time has expired waiting for the shutdown acknowledgement or completion messages, the standby appliance begins its procedures to become active. From
A flowchart in
Once the WWPN address is programmed into standby FC adapter 517, SAN client 500 will not be aware of the change in appliances. Standby appliance 530 will now receive all the data traffic that was bound for failed primary appliance 525. When a standby appliance is a fail-over appliance for one or more than one primary appliances, a table is kept to store and keep track of the information needed to emulate the primary appliances, which includes the WWPN addresses.
The technology of the present invention is not limited to one standby appliance that can act as a fail-over to a set of primary appliances. As illustrated in
It should be understood by those skilled in the art that the present description is provided only by way of illustrative example and should in no manner be construed to limit the invention as described herein. Numerous modifications and alternate embodiments of the invention will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the following claims.
McNulty, Stephen Anthony, Chen, Sheng-Wei
| Patent | Priority | Assignee | Title |
| 9088609, | Dec 24 2009 | International Business Machines Corporation | Logical partition media access control impostor detector |
| 9130987, | Dec 24 2009 | International Business Machines Corporation | Logical partition media access control impostor detector |
| 9491194, | Dec 24 2009 | International Business Machines Corporation | Logical partition media access control impostor detector |
| Patent | Priority | Assignee | Title |
| 5136498, | Sep 26 1990 | Honeywell Inc. | Method for enacting failover of a 1:1 redundant pair of slave processors |
| 5151987, | Oct 23 1990 | International Business Machines Corporation | Recovery objects in an object oriented computing environment |
| 5202822, | Sep 26 1990 | Honeywell Inc. | Universal scheme of input/output redundancy in a process control system |
| 5206946, | Oct 27 1989 | SAND TECHNOLOGY SYSTEMS DEVELOPMENT INC | Apparatus using converters, multiplexer and two latches to convert SCSI data into serial data and vice versa |
| 5237695, | Nov 01 1991 | Hewlett-Packard Company | Bus contention resolution method for network devices on a computer network having network segments connected by an interconnection medium over an extended distance |
| 5274783, | Jun 28 1991 | Maxtor Corporation | SCSI interface employing bus extender and auxiliary bus |
| 5287537, | Nov 15 1985 | Data General Corporation | Distributed processing system having plural computers each using identical retaining information to identify another computer for executing a received command |
| 5325527, | Jan 19 1993 | Canon Kabushiki Kaisha | Client/server communication system utilizing a self-generating nodal network |
| 5333277, | Jan 10 1992 | Exportech Trading Company | Data buss interface and expansion system |
| 5388243, | Mar 09 1990 | EMC Corporation | Multi-sort mass storage device announcing its active paths without deactivating its ports in a network architecture |
| 5463772, | Apr 23 1993 | HEWLETT-PACKARD DEVELOPMENT COMPANY, L P | Transparent peripheral file systems with on-board compression, decompression, and space management |
| 5471634, | Mar 29 1994 | The United States of America as represented by the Secretary of the Navy | Network file server with automatic sensing means |
| 5491812, | Sep 28 1992 | Quantum Corporation | System and method for ethernet to SCSI conversion |
| 5504757, | Sep 27 1994 | International Business Machines Corporation | Method for selecting transmission speeds for transmitting data packets over a serial bus |
| 5524175, | Oct 29 1992 | Hitachi, Ltd.; Hitachi Micro Computer System, Ltd. | Neuro-computer system for executing a plurality of controlling algorithms |
| 5528765, | Jun 15 1993 | R. C. Baker & Associates Ltd. | SCSI bus extension system for controlling individual arbitration on interlinked SCSI bus segments |
| 5548731, | Jan 13 1993 | International Business Machines Corporation | System for forwarding data packets with different formats to different software entitles respectively based upon match between portion of data packet and filter |
| 5548783, | Oct 28 1993 | Dell USA, L.P.; Dell USA L P | Composite drive controller including composite disk driver for supporting composite drive accesses and a pass-through driver for supporting accesses to stand-alone SCSI peripherals |
| 5561812, | Sep 16 1992 | Bull S.A. | Data transmission system for transferring data between a computer bus and a network using a plurality of command files to reduce interruptions between microprocessors |
| 5566331, | Jan 24 1994 | University Corporation for Atmospheric Research | Mass storage system for file-systems |
| 5574861, | Dec 21 1993 | Verizon Patent and Licensing Inc | Dynamic allocation of B-channels in ISDN |
| 5574862, | Apr 14 1993 | Radius Inc. | Multiprocessing system with distributed input/output management |
| 5596723, | Jun 23 1994 | Dell USA, LP; DELL USA, L P | Method and apparatus for automatically detecting the available network services in a network system |
| 5613160, | Nov 18 1992 | Canon Kabushiki Kaisha | In an interactive network board, method and apparatus for placing a network peripheral in a default configuration |
| 5640541, | Mar 24 1995 | OpenConnect Systems Incorporated | Adapter for interfacing a SCSI bus with an IBM system/360/370 I/O interface channel and information system including same |
| 5664221, | Nov 14 1995 | Hewlett Packard Enterprise Development LP | System for reconfiguring addresses of SCSI devices via a device address bus independent of the SCSI bus |
| 5787019, | May 10 1996 | Apple Computer, Inc.; Apple Computer, Inc | System and method for handling dynamic changes in device states |
| 5812751, | May 19 1995 | QNAP SYSTEMS, INC | Multi-server fault tolerance using in-band signalling |
| 5819054, | Jun 30 1993 | Hitachi, Ltd. | Storage system realizing scalability and fault tolerance |
| 5892955, | Sep 20 1996 | EMC IP HOLDING COMPANY LLC | Control of a multi-user disk storage system |
| 5923850, | Jun 28 1996 | Oracle America, Inc | Historical asset information data storage schema |
| 5925119, | Mar 28 1997 | Quantum Corporation | Computer architecture for automated storage library |
| 5941972, | Dec 31 1997 | Crossroads Systems, Inc. | Storage router and method for providing virtual local storage |
| 5991813, | May 16 1997 | ICon CMT Corp. | Network enabled SCSI interface |
| 5996024, | Jan 14 1998 | EMC IP HOLDING COMPANY LLC | Method and apparatus for a SCSI applications server which extracts SCSI commands and data from message and encapsulates SCSI responses to provide transparent operation |
| 6003065, | Apr 24 1997 | Oracle America, Inc | Method and system for distributed processing of applications on host and peripheral devices |
| 6041381, | Feb 05 1998 | CF DB EZ LLC | Fibre channel to SCSI addressing method and system |
| 6108300, | May 02 1997 | Cisco Technology, Inc | Method and apparatus for transparently providing a failover network device |
| 6178173, | Dec 30 1996 | HANGER SOLUTIONS, LLC | System and method for communicating pre-connect information in a digital communication system |
| 6188997, | Apr 19 1999 | Pitney Bowes Inc | Postage metering system having currency synchronization |
| 6263445, | Jun 30 1998 | EMC IP HOLDING COMPANY LLC | Method and apparatus for authenticating connections to a storage system coupled to a network |
| 6363497, | May 13 1997 | Round Rock Research, LLC | System for clustering software applications |
| 6449733, | Dec 07 1998 | HEWLETT-PACKARD DEVELOPMENT COMPANY, L P | On-line replacement of process pairs in a clustered processor architecture |
| 6496942, | Aug 25 1998 | NetApp, Inc | Coordinating persistent status information with multiple file servers |
| 6523131, | May 13 1997 | Round Rock Research, LLC | Method for communicating a software-generated pulse waveform between two servers in a network |
| 6574753, | Jan 10 2000 | EMC IP HOLDING COMPANY LLC | Peer link fault isolation |
| 6658004, | Dec 28 1999 | S AQUA SEMICONDUCTOR, LLC | Use of beacon message in a network for classifying and discarding messages |
| 6735200, | Mar 21 2000 | International Business Machines Corporation | Method and apparatus for monitoring the availability of nodes in a communications network |
| 7000121, | Jun 15 2000 | Fujitsu Services Limited | Computer systems, in particular virtual private networks |
| 20010056554, | |||
| 20020129159, |
| Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
| Mar 30 2006 | Falconstor, Inc. | (assignment on the face of the patent) | / |
| Date | Maintenance Fee Events |
| Sep 23 2011 | M1552: Payment of Maintenance Fee, 8th Year, Large Entity. |
| Oct 04 2011 | STOL: Pat Hldr no Longer Claims Small Ent Stat |
| May 17 2013 | ASPN: Payor Number Assigned. |
| Aug 19 2015 | LTOS: Pat Holder Claims Small Entity Status. |
| Aug 25 2015 | M2553: Payment of Maintenance Fee, 12th Yr, Small Entity. |
| Date | Maintenance Schedule |
| Sep 13 2014 | 4 years fee payment window open |
| Mar 13 2015 | 6 months grace period start (w surcharge) |
| Sep 13 2015 | patent expiry (for year 4) |
| Sep 13 2017 | 2 years to revive unintentionally abandoned end. (for year 4) |
| Sep 13 2018 | 8 years fee payment window open |
| Mar 13 2019 | 6 months grace period start (w surcharge) |
| Sep 13 2019 | patent expiry (for year 8) |
| Sep 13 2021 | 2 years to revive unintentionally abandoned end. (for year 8) |
| Sep 13 2022 | 12 years fee payment window open |
| Mar 13 2023 | 6 months grace period start (w surcharge) |
| Sep 13 2023 | patent expiry (for year 12) |
| Sep 13 2025 | 2 years to revive unintentionally abandoned end. (for year 12) |