Disk cache device and method for secure writing of hard disks in mass memory subsystems

• US 6,480,933 B1
• Filed: 07/06/2000
• Issued: 11/12/2002
• Est. Priority Date: 11/06/1998
• Status: Expired due to Term

• Current Assignee: Bull Sas (Atos SE)
• Original Assignee: Bull Sas (Atos SE)
• Inventors: Cargemel, Laurent, Carteau, Daniel, Delepoulle, Jacques
• Primary Examiner(s): Ellis, Kevin L.
• Application Number:
  US09/582,875
• Time in Patent Office: 859 Days
• Field of Search: 711/113, 711/138, 711/139, 713/340
• US Class Current: 711/113
• CPC Class Codes: G06F 11/0754 by exceeding limits
• CPC Class Codes: G06F 12/0804 with main memory updating G06F12/0806 takes precedence
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache

Abstract

A disk cache device for secure writing comprising a backup power supply source (62) for supplying backup power for a given duration to a computer system fed by two main electric power supply devices (60, 61) and comprising at least one hard disk drive (1a, 1b, 1c), and a host system (3). All of the disk drives (1a, 1b, 1c) are linked by a bus (2) to a connection (30) of the host system (3) (host bus adapter), and a monitor (50) for monitoring at least the backup electric power supply source (62) and the main power supply devices (60, 61). Monitors (50) are connected to the interface (2) and can be interrogated by an interrogator (31) for interrogating the host system (3) so that the latter can enable the write disk cache function, or not, in the write commands to be sent to the disk drives (1a, 1b, 1c) in accordance with the information gathered by the monitoring means (50).

Claims

1. Disk cache device for secure writing comprising a host system (3) an adapter (30) for linking the host system to a bus (2), an interface (12) and at least one hard disk drive (1), a backup power source (62) for supplying backup power for a given duration, and at least one power supply main device (60, 61) for supplying electric power to the disk drive, a monitor (50) for monitoring at least the backup power supply source (62) and the main power supply devices (60, 61), the host system including an interrogator (31), the monitor (50) being connected to the interface (2) and adapted to be interrogated by the interrogator (31) of the host system (3) so that the host system can enable a write disk cache function, or not, in write commands to be sent to the disk drive or drives (1a, 1b, 1c), in accordance with the information gathered by the monitor (50).

2. A disk cache device for secure writing according to claim 1, characterized in that the information gathered by the monitor (50) represents the operating state of each main power supply device (60, 61) and of the backup power supply source (62).

3. A disk cache device for secure writing according to claim 1, characterized in that a write cache function is enabled by the host system (3) in write commands as long as the main power supply devices (60, 61) and the backup power supply source (62) are operational.

4. A disk cache device for secure writing according to claim 2, characterized in that a write cache function is enabled by the host system (3) in write commands as long as the main power supply devices (60, 61) and the backup power supply source (62) are operational.

5. A disk cache device for secure writing according to claim 1, including a plurality of disk drives (1a, 1b, 1c), each having a corresponding disk cache (13a, 13b, 13c), the host system (3) being adapted to initiate writing of data contained in all the disk caches (13a, 13b, 13c) of the disk drives (1a, 1b, 1c) onto respective magnetic mediums (10a, 10b, 10c) as soon as the information gathered by the monitor (50) indicates that the main power supplies (60, 61) and the backup power supply means have failed.

6. A disk cache device for secure writing according to claim 2, including a plurality of disk drives (1a, 1b, 1c), each having a corresponding disk cache (13a, 13b, 13c), the host system (3) being adapted to initiate writing of data contained in all the disk caches (13a, 13b, 13c) of the disk drives (1a, 1b, 1c) onto respective magnetic mediums (10a, 10b, 10c) as soon as the information gathered by the monitor (50) indicates that the main power supplies (60, 61) and the backup power supply means have failed.

7. A disk cache device for secure writing according to claim 3, including a plurality of disk drives (1a, 1b, 1c), each having a corresponding disk cache (13a, 13b, 13c), the host system (3) being adapted to initiate writing of data contained in all the disk caches (13a, 13b, 13c) of the disk drives (1a, 1b, 1c) onto respective magnetic mediums (10a, 10b, 10c) as soon as the information gathered by the monitor (50) indicates that the main power supplies (60, 61) and the backup power supply means have failed.

8. A disk cache device for secure writing according to claim 4, including a plurality of disk drives (1a, 1b, 1c), each having a corresponding disk cache (13a, 13b, 13c), the host system (3) being adapted to initiate writing of data contained in all the disk caches (13a, 13b, 13c) of the disk drives (1a, 1b, 1c) onto respective magnetic mediums (10a, 10b, 10c) as soon as the information gathered by the monitor (50) indicates that the main power supplies (60, 61) and the backup power supply means have failed.

9. A disk cache device for secure writing according to claim 5, characterized in that the interrogator (31) comprises an agent installed at a level higher than that of a driver of the adapter (30) so as to perform a polling of the monitor (50) at a given time interval and set a flag indicating whether or not a write cache function is authorized, said flag being consulted by the adapter (30) of the host system (3) before each sending of a write command to at least one disk (1a, 1b, 1c).

10. A disk cache device for secure writing according to claim 6, characterized in that the interrogator (31) comprises an agent installed at a level higher than that of a driver of the adapter (30) so as to perform a polling of the monitor (50) at a given time interval and set a flag indicating whether or not a write cache function is authorized, said flag being consulted by the adapter (30) of the host system (3) before each sending of a write command to at least one disk (1a, 1b, 1c).

11. A disk cache device for secure writing according to claim 7, characterized in that the interrogator (31) comprises an agent installed at a level higher than that of a driver of the adapter (30) so as to perform a polling of the monitor (50) at a given time interval and set a flag indicating whether or not a write cache function is authorized, said flag being consulted by the adapter (30) of the host system (3) before each sending of a write command to at least one disk (1a, 1b, 1c).

12. A disk cache device for secure writing according to claim 8, characterized in that the interrogator (31) comprises an agent installed at a level higher than that of a driver of the adapter (30) so as to perform a polling of the monitor (50) at a given time interval and set a flag indicating whether or not a write cache function is authorized, said flag being consulted by the adapter (30) of the host system (3) before each sending of a write command to at least one disk (1a, 1b, 1c).

13. A disk cache device for secure writing according to claim 5, characterized in that the period during which the power supply source (62) must allow the proper functioning of the computer system corresponds to at least the time required for the data contained in each disk cache (13a, 13b, 13c) of a disk drive (1a, 1b, 1c) to be written onto the magnetic medium (10a, 10b, 10c) plus the required time lapse between two interrogations of the monitor (50).

14. A disk cache device for secure writing according to claim 6, characterized in that the period during which the power supply source (62) must allow the proper functioning of the computer system corresponds to at least the time required for the data contained in each disk cache (13a, 13b, 13c) of a disk drive (1a, 1b, 1c) to be written onto the magnetic medium (10a, 10b, 10c) plus the required time lapse between two interrogations of the monitor (50).

15. A disk cache device for secure writing according to claim 7, characterized in that the period during which the power supply source (62) must allow the proper functioning of the computer system corresponds to at least the time required for the data contained in each disk cache (13a, 13b, 13c) of a disk drive (1a, 1b, 1c) to be written onto the magnetic medium (10a, 10b, 10c) plus the required time lapse between two interrogations of the monitor (50).

16. A disk cache device for secure writing according to claim 8, characterized in that the period during which the power supply source (62) must allow the proper functioning of the computer system corresponds to at least the time required for the data contained in each disk cache (13a, 13b, 13c) of a disk drive (1a, 1b, 1c) to be written onto the magnetic medium (10a, 10b, 10c) plus the required time lapse between two interrogations of the monitor (50).

17. A disk cache device for secure writing according to claim 5, characterized in that it further comprises an integrated circuit that monitors the backup electric power supply source (62) and each main electric power supply device (60, 61) and that sends through the bus (2) an interface signal for denying the bus'"'"'s access to the host system (3) during a given period so that no further command is transmitted to the disk drives (1a, 1b, 1c).

18. A disk cache device for secure writing according to claim 6, characterized in that it further comprises an integrated circuit that monitors the backup electric power supply source (62) and each main electric power supply device (60, 61) and that sends through the bus (2) an interface signal for denying the bus'"'"'s access to the host system (3) during a given period so that no further command is transmitted to the disk drives (1a, 1b, 1c).

19. A disk cache device for secure writing according to claim 7, characterized in that it further comprises an integrated circuit that monitors the backup electric power supply source (62) and each main electric power supply device (60, 61) and that sends through the bus (2) an interface signal for denying the bus'"'"'s access to the host system (3) during a given period so that no further command is transmitted to the disk drives (1a, 1b, 1c).

20. A disk cache device for secure writing according to claim 8, characterized in that it further comprises an integrated circuit that monitors the backup electric power supply source (62) and each main electric power supply device (60, 61) and that sends through the bus (2) an interface signal for denying the bus'"'"'s access to the host system (3) during a given period so that no further command is transmitted to the disk drives (1a, 1b, 1c).

21. A disk cache device for secure writing according to claim 9, characterized in that it further comprises an integrated circuit that monitors the backup electric power supply source (62) and each main electric power supply device (60, 61) and that sends through the bus (2) an interface signal for denying the bus'"'"'s access to the host system (3) during a given period so that no further command is transmitted to the disk drives (1a, 1b, 1c).

22. A disk cache device for secure writing according to claim 10, characterized in that it further comprises an integrated circuit that monitors the backup electric power supply source (62) and each main electric power supply device (60, 61) and that sends through the bus (2) an interface signal for denying the bus'"'"'s access to the host system (3) during a given period so that no further command is transmitted to the disk drives (1a, 1b, 1c).

23. A disk cache device for secure writing according to claim 11, characterized in that it further comprises an integrated circuit that monitors the backup electric power supply source (62) and each main electric power supply device (60, 61) and that sends through the bus (2) an interface signal for denying the bus'"'"'s access to the host system (3) during a given period so that no further command is transmitted to the disk drives (1a, 1b, 1c).

24. A disk cache device for secure writing according to claim 12, characterized in that it further comprises an integrated circuit that monitors the backup electric power supply source (62) and each main electric power supply device (60, 61) and that sends through the bus (2) an interface signal for denying the bus'"'"'s access to the host system (3) during a given period so that no further command is transmitted to the disk drives (1a, 1b, 1c).

25. A disk cache device for secure writing according to claim 13, characterized in that it further comprises an integrated circuit that monitors the backup electric power supply source (62) and each main electric power supply device (60, 61) and that sends through the bus (2) an interface signal for denying the bus'"'"'s access to the host system (3) during a given period so that no further command is transmitted to the disk drives (1a, 1b, 1c).

26. A disk cache device for secure writing according to claim 14, characterized in that it further comprises an integrated circuit that monitors the backup electric power supply source (62) and each main electric power supply device (60, 61) and that sends through the bus (2) an interface signal for denying the bus'"'"'s access to the host system (3) during a given period so that no further command is transmitted to the disk drives (1a, 1b, 1c).

27. A disk cache device for secure writing according to claim 15, characterized in that it further comprises an integrated circuit that monitors the backup electric power supply source (62) and each main electric power supply device (60, 61) and that sends through the bus (2) an interface signal for denying the bus'"'"'s access to the host system (3) during a given period so that no further command is transmitted to the disk drives (1a, 1b, 1c).

28. A disk cache device for secure writing according to claim 16, characterized in that it further comprises an integrated circuit that monitors the backup electric power supply source (62) and each main electric power supply device (60, 61) and that sends through the bus (2) an interface signal for denying the bus'"'"'s access to the host system (3) during a given period so that no further command is transmitted to the disk drives (1a, 1b, 1c).

29. A method for secure writing in a computer system comprising at least one hard disk drive (1a, 1b, 1c) fed by at least one main electric power supply device (60, 61) and a backup electric power supply (62) for supplying power for a given duration, a host system (3) linked by an adapter (30) of the system and a bus (2) to at least the disk drive, and a monitor (50) for monitoring at least the backup electric power supply source (62) and the main power supply devices (60, 61), characterized in that the method comprises:

monitoring the backup power supply source (62) and each electric power supply device (60, 61),

indicating the state of the backup power supply means (62) and of each electric power supply device (60, 61),

enabling a write disk cache function if the backup power supply means (62) and the two electric power supply devices (60, 61) are all operational, and, if not, providing a backup step for disabling the write disk cache function and a step for writing the data contained in the disk caches (13a, 13b, 13c) of the disk drives (1a, 1b, 1c) onto magnetic media (10a, 10b, 10c) of the disk drives (1a, 1b, 1c).