SCSI-coupled module for monitoring and controlling SCSI-coupled raid bank and bank environment

• US 5,835,700 A
• Filed: 08/16/1996
• Issued: 11/10/1998
• Est. Priority Date: 11/12/1993
• Status: Expired due to Term

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology plc (Seagate Technology Holdings Plc)
• Inventors: Carbonneau, Guy A., Wu, Bernie, Jones, Tim
• Primary Examiner(s): PALYS, JOSEPH E
• Application Number:
  US08/698,951
• Time in Patent Office: 816 Days
• Field of Search: 395/183.2, 395/184.01, 395/182.04, 395/185.1, 395/833, 395/835, 395/838, 395/839, 395/182.03, 395/182.05, 395/183.18, 395/183.17
• US Class Current: 714/44
• CPC Class Codes: G06F 11/221 to test buses, lines or interfaces, e.g. stuck-at or open line faults
• CPC Class Codes: G06F 11/3034 where the computing system component is a storage system, e.g. DASD based or network based digital input from or digital output to record carriers G06F3/06; digital recording or reproducing G11B20/18; for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS], H04L67/1097
• CPC Class Codes: G06F 11/3048 where the topology of the computing system or computing system component explicitly influences the monitoring activity, e.g. serial, hierarchical systems
• CPC Class Codes: G06F 11/3058 Monitoring arrangements for monitoring environmental properties or parameters of the computing system or of the computing system component, e.g. monitoring of power, currents, temperature, humidity, position, vibrations thermal management in cooling arrangements of a computing system G06F1/206
• CPC Class Codes: G06F 11/3485 for I/O devices
• CPC Class Codes: G06F 11/349 for interfaces, buses
• CPC Class Codes: G06F 21/86 Secure or tamper-resistant housings
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0614 Improving the reliability of storage systems
• CPC Class Codes: G06F 3/0653 Monitoring storage devices or systems
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

An intelligent status monitoring, reporting and control module is coupled to a SCSI bus that interconnects a cluster of SCSI-compatible data storage modules (e.g., magnetic disk drives). The status monitoring, reporting and control module is otherwise coupled to the cluster of SCSI-compatible data storage modules and to power maintenance and/or other maintenance subsystems of the cluster for monitoring and controlling states of the data storage modules and power maintenance and/or other maintenance subsystems that are not readily monitored or controlled directly by way of the SCSI bus. The status monitoring, reporting and control module sends status reports to a local or remote system supervisor and executes control commands supplied by the local or remote system supervisor. The status reports include reports about system temperature and power conditions. The executable commands include commands for regulating system temperature and power conditions.

Claims

1. A digital data storage system comprising:

a SCSI bus;

a plurality of individually transportable data storage units each operatively but removably coupled to the SCSI bus for transferring data stored or data to-be-stored in said data storage unit over the SCSI bus in accordance with SCSI protocol, at least two of said storage units defining a RAID cluster wherein file data is preserved even if one storage unit within the cluster fails;

a status defining module operatively coupled to the SCSI bus for transferring status-defining data over the SCSI bus in accordance with the SCSI protocol;

a cabinet for securely enclosing the plural data storage units and the status defining module, the cabinet having one or more lockable access doors, at least one of the doors defining a means by way of which one or more of the plural data storage units may be physically accessed for disconnection from the SCSI bus and removal from the cabinet;

one or more door locking mechanisms for locking one or more closed ones of the lockable access doors; and

one or more door status sensors operatively coupled to the one or more access doors for detecting whether each access door is in an open or closed state,

wherein said status defining module includes accessibility reporting means, operatively coupled to said one or more door status sensors, for interrogating the one or more door status sensors and for outputting a door-status report onto the SCSI bus as part of said status-defining data, the door-status report indicating whether each of the one or more access doors is open or closed; and

further

wherein;

one or more of said door locking mechanisms is an automatic door locking mechanism operatively coupled to the status defining module for automatically locking a respective one or more closed ones of the lockable access doors in response to a respective lock activating signal sent by the status defining module; and

the status defining module includes means for sending the respective lock activating signal to each respective automatic door locking mechanism.

2. A digital data storage system according to claim 1 wherein

said one or more automatic door locking mechanisms are further for automatically unlocking a respective one or more locked ones of the lockable access doors in response to a respective unlocking signal sent by the status defining module;

and

the status defining module further includes means for sending the respective unlocking signal to each respective automatic door locking mechanism.

3. A digital data storage system according to claim 2 wherein:

the status defining module further includes lock-status reporting means for sending a lock-status report over said SCSI bus as part of said status-defining data, the lock-status report indicating whether a given one or more of the automatic door locking mechanisms is in a locked or unlocked state.

4. A digital data storage system comprising:

a SCSI bus;

a plurality of individually transportable data storage units each operatively but removably coupled to the SCSI bus for transferring data stored or data to-be-stored in said data storage unit over the SCSI bus in accordance with SCSI protocol, at least two of said storage units defining a RAID cluster wherein file data is preserved even if one storage unit within the cluster fails;

a status defining module operatively coupled to the SCSI bus for transferring status-defining data over the SCSI bus in accordance with the SCSI protocol;

a cabinet for securely enclosing the plural data storage units and the status defining module, the cabinet having one or more lockable access doors, at least one of the doors defining a means by way of which one or more of the plural data storage units may be physically accessed for disconnection from the SCSI bus and removal from the cabinet;

one or more door locking mechanisms for locking one or more closed ones of the lockable access doors; and

one or more door status sensors operatively coupled to the one or more access doors for detecting whether each access door is in an open or closed state,

wherein said status defining module includes accessibility reporting means, operatively coupled to said one or more door status sensors, for interrogating the one or more door status sensors and for outputting a door-status report onto the SCSI bus as part of said status-defining data, the door-status report indicating whether each of the one or more access doors is open or closed; and

further wherein;

said cabinet is further for securely enclosing two or more modularly-replaceable redundant power supplies;

said lockable access doors include first and second automatically lockable access doors that are automatically lockable in response to signals output by the status defining module;

the first automatically lockable access door is usable for removing one or more of the data storage units but not usable for removing the two or more modularly-replaceable redundant power supplies; and

the second automatically lockable access door is usable for removing one or more of the modularly-replaceable redundant power supplies.

5. A digital data storage system according to claim 4 wherein:

said cabinet is further for securely enclosing two or more removable cages, each cage supporting a subset of said plurality of individually transportable data storage units;

the first automatically lockable access door is not usable for removing the two or more removable cages; and

the second automatically lockable access door is usable for removing one or more of the removable cages.

6. A data storage and communications system comprising:

(a) a first computer contained in a first enclosure and functioning as a data-transfer bridge between an external local area network and an external first SCSI bus;

(b) a first plurality of removable data storage units located outside said first enclosure, each of said data storage units being operatively but removably coupled to the first SCSI bus for transferring data stored or data to-be-stored in said data storage unit over the SCSI bus in accordance with SCSI protocol,

(b.1) wherein each given one of the first plurality of data storage units has no means for directly reporting to the first SCSI bus, the status of a local condition of the given data storage unit, said local condition including at least one member selected from the group consisting of;

(b.1a) a local power voltage level of the given data storage unit;

(b.1b) a local power current level of the given data storage unit;

(b.1c) a local temperature level of the given data storage unit; and

(b.1d) a manual removability status of the given data storage unit;

(b.1e) a physical presence status of the given data storage unit; and

said system further comprising;

(c) a first status defining module operatively coupled to the first SCSI bus for transferring status-defining data over the first SCSI bus in accordance with the SCSI protocol, the status defining module being further operatively coupled to said first plurality of data storage units for periodically monitoring one or more of said local conditions of each given data storage unit and for issuing one or more status reports indicative of the monitored one or more local conditions of each given data storage unit over the first SCSI bus in accordance with the SCSI protocol;

(a.1) wherein the first computer does not periodically monitor the one or more of said local conditions of each given data storage unit among said first plurality of data storage units independently of said periodic monitoring by the first status defining module.

7. A data storage and communications system according to claim 6 (a.2) wherein the first computer does not have means for periodically monitoring the one or more of said local conditions of each given data storage unit.

8. As data storage and communications system according to claim 6 and further comprising:

(d) a second computer located outside the first enclosure and operatively coupled to the local area network so as to communicate with the first status defining module by way of the first SCSI bus and further by way of the first computer functioning as said data-transfer bridge.

9. A data storage and communications system according to claim 8 wherein

(c.1) said first status defining module is further for recognizing on its own when a periodically monitored one or more of said local conditions of each given data storage unit is at or degrading towards a predefined, unacceptable state and for responsively issuing a corresponding one or more warning reports indicative of the unacceptable state or degradation thereto over the first SCSI bus in accordance with the SCSI protocol to the second computer by way of the first computer.

10. A data storage and communications system according to claim 6 (a.2) wherein the first computer is further coupled to a wireless paging system;

and

(c.1) said first status defining module is further for recognizing on its own when a periodically monitored one or more of said local conditions of each given data storage unit is at or degrading towards a predefined, unacceptable state and for responsively issuing a corresponding one or more warning reports indicative of the unacceptable state or degradation thereto over the first SCSI bus in accordance with the SCSI protocol to the wireless paging system by way of the first computer.

11. A data storage and communications system according to claim 6 wherein:

(aa) the first computer further functions as a data-transfer bridge between said external local area network and an external second SCSI bus;

and said data storage and communications system further comprises;

(bb) a second plurality of removable data storage units located outside said first enclosure, each of said second data storage units being operatively but removably coupled to the second SCSI bus for transferring data stored or data to-be-stored in said data storage unit over the second SCSI bus in accordance with SCSI protocol,

(bb.1) wherein each given one of the second plurality of data storage units has no means for directly reporting to the second SCSI bus, the status of a local condition of the given data storage unit, said local condition including at least one member selected from said group of local conditions;

(cc) a second status defining module operatively coupled to the second SCSI bus for transferring status-defining data over the second SCSI bus in accordance with the SCSI protocol, the status defining module being further operatively coupled to said second plurality of data storage units for periodically monitoring one or more of said local conditions of each given data storage unit among said second plurality and for issuing one or more status reports indicative of the monitored one or more local conditions of each given data storage unit over the second SCSI bus in accordance with the SCSI protocol;

(aa.1) wherein the first computer does not periodically monitor the one or more of said local conditions of each given data storage unit among said second plurality of data storage units independently of said periodic monitoring by the second status defining module.

12. A data storage and communications system according to claim 6 wherein at least two of said storage units define a RAID cluster, said RAID cluster being one wherein file data is preserved even if one storage unit within the cluster fails.

13. A data storage and communications system according to claim 6 wherein said status defining module comprises:

nonvolatile writable memory means for nonvolatily maintaining a usage history for the first plurality of removable data storage units.

14. A data storage and communications system according to claim 6 wherein said status defining module comprises:

serial communication means for carrying serial signals representative of said monitored local conditions.

15. A data storage and communications system according to claim 6 wherein said status defining module comprises:

nonvolatile writable memory means for nonvolatily maintaining a history of messaging errors occurring along said first SCSI bus.

16. A data storage and communications system according to claim 6 further comprising:

a second enclosure housing said first plurality of removable data storage units and also housing said first status defining module;

wherein said first SCSI bus carries SCSI signals between the first and second enclosures; and

wherein said second enclosure has a tower configuration within which the first plurality of removable data storage units are disposed in a stacked formation.

17. A data storage and communications system according to claim 16 wherein:

(aa) the first computer further functions as a data-transfer bridge between said external local area network and an external second SCSI bus;

and said data storage and communications system further comprises;

(bb) a second plurality of removable data storage units located outside said first enclosure and housed in the second enclosure, each of said second data storage units being operatively but removably coupled to the second SCSI bus for transferring data stored or data to-be-stored in said data storage unit over the second SCSI bus in accordance with SCSI protocol,

(bb.1) wherein each given one of the second plurality of data storage units has no means for directly reporting to the second SCSI bus, the status of a local condition of the given data storage unit, said local condition including at least one member selected from said group of local conditions;

(cc) a second status defining module operatively coupled to the second SCSI bus for transferring status-defining data over the second SCSI bus in accordance with the SCSI protocol, the status defining module being further operatively coupled to said second plurality of data storage units for periodically monitoring one or more of said local conditions of each given data storage unit among said second plurality and for issuing one or more status reports indicative of the monitored one or more local conditions of each given data storage unit over the second SCSI bus in accordance with the SCSI protocol;

(aa.1) wherein the first computer does not periodically monitor the one or more of said local conditions of each given data storage unit among said second plurality of data storage units independently of said periodic monitoring by the second status defining module; and

said system further comprises;

a common messaging panel provided on the second enclosure and operatively coupled to the first and second status defining modules for providing a local-site interface between the outside of said second enclosure and the first and second status defining modules.

18. A data storage and communications system according to claim 17 wherein:

said common messaging panel outputs an audible alarm signal for identifying the second enclosure as an enclosure that is requesting servicing.

19. A data storage and communications system according to claim 17 wherein:

said common messaging panel outputs a flashing visual alarm signal for identifying the second enclosure as an enclosure that is requesting servicing.

20. A data storage and communications system according to claim 17 wherein:

said common messaging panel includes key input means operatively coupled to said first and second status defining modules for allowing a service technician to manually supply a pre-defined access request code to the first and second status defining modules; and

a verification copy of said pre-defined access request code is downloadable to one or both of the first and second status defining modules by way of the respective first and second SCSI buses.

21. A data storage and communications system according to claim 20 wherein:

each of said first and second status defining modules includes means for placing one or more units in the respective first and second plurality of data storage units into a quiescent state.