Array storage system for returning an I/O complete signal to a virtual I/O daemon that is separated from software array driver and physical device driver

• US 5,598,549 A
• Filed: 06/11/1993
• Issued: 01/28/1997
• Est. Priority Date: 06/11/1993
• Status: Expired due to Term

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: AT&T Global Network Services LLC (AT&T, Inc.), Symbios Logic Incorporated (Broadcom, Inc.), Hyundai Electronics America Incorporated (SK Hynix Inc.)
• Inventors: Rathunde, Dale F.
• Primary Examiner(s): Lee, Thomas C.
• Assistant Examiner(s): Chen, Anderson I.
• Application Number:
  US08/076,652
• Time in Patent Office: 1,327 Days
• Field of Search: 395/275, 395/725, 395/425, 395/182.04, 395/404, 395/441, 364/236.2, 364/238.3
• US Class Current: 711/114
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 2003/0697 device management, e.g. handlers, drivers, I/O schedulers
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems

Abstract

A scalable software architecture, for optimal performance on a RAID level 1, 3, 4 and 5 disk array or tape array. The software architecture consists of a software device driver and one or more driver daemon processes to control I/O requests to the arrays. Implemented in a UNIX or NetWare operating environment, this architecture provides a transparent interface to the kernels I/O subsystem, physical device drivers and system applications. The array driver and I/O daemon can be run on a uni-processor or multi-processor system platform to optimize job control, error recovery, data recreation, parity generation and asynchronous writes.

Claims

1. An array storage system, comprising:

a plurality of drives for storing data;

a physical device driver corresponding to each one of said plurality of drives;

a software array driver module for receiving a system I/O request and translating said system I/O request into one or more virtual I/O requests, said virtual I/O request being provided to one or more of said physical device drivers;

each one of said physical device drivers receiving a virtual I/O request operating to translate said received I/O request into a physical I/O request, said physical I/O request being provided to said drive corresponding to said one of said physical device drivers;

a separate call-back module, different from said physical device drivers, for receiving physical I/O complete signals from said plurality of drives and translating said physical I/O complete signals into one or more virtual I/O complete signals corresponding to said one or more virtual I/O requests; and

a separate virtual I/O daemon module, different from said software array driver module, for receiving said one or more virtual I/O complete signals from said call-back module and translating said received virtual I/O complete signals into a system I/O complete signal;

wherein said one or more virtual I/O complete signals are communicated to said virtual I/O daemon module independently of said physical device drivers and said software array driver module.

2. The array storage system according to claim 1, wherein:

said plurality of drives includes at least one drive for storing parity information; and

virtual I/O requests directed to said parity drive are executed independently of virtual I/O requests directed to said data drives.

3. The array storage system according to claim 1, wherein:

said plurality of drives includes at least one drive for storing parity information; and

said virtual I/O daemon module generates said system I/O complete signal prior to receipt of virtual I/O complete signals corresponding to said virtual I/O requests directed to said parity drive.

4. The array storage system according to claim 1, wherein:

said virtual I/O daemon module monitors the operational status of said drives and generates additional virtual I/O requests necessary to recreate data residing on a failed drive in response to a read I/O request, said additional virtual I/O requests being provided to said device driver.

5. The array system according to claim 4, wherein:

said software array driver module and said virtual I/O daemon module include a hash table implementation to insure the integrity of data and parity during virtual I/O operations and array error recovery procedures.

6. The array system according to claim 5, wherein:

each one of said virtual I/O requests accesses up to one cluster of data on one drive in said plurality of drives; and

said hash table implementation determines a hash table entry for said cluster.

7. The array system according to claim 1, wherein:

said array storage system is configured in accordance with RAID level 5; and

said virtual I/O daemon module generates additional virtual I/O requests necessary to generate parity information in response to a write I/O request, said additional virtual I/O requests being provided to said device driver.

8. The array system according to claim 7, wherein:

said virtual I/O daemon module generates said system I/O complete signal prior to receipt of virtual I/O complete signals corresponding to said additional virtual I/O requests necessary to generate parity information.

9. The array system according to claim 7, wherein:

said software array driver module and said virtual I/O daemon module include a hash table implementation to insure the integrity of data and parity during virtual I/O operations.

10. The array system according to claim 9, wherein:

each one of said virtual I/O requests accesses up to one cluster of data on one drive in said plurality of drives; and

said hash table implementation determines a hash table entry for said cluster.

11. The array storage system according to claim 1, wherein:

said array storage system includes a plurality of virtual I/O daemon modules capable of processing virtual jobs in parallel.

12. The array storage system according to claim 1, wherein:

said array storage system is included within a multiprocessor computer system; and

said array storage system includes a tunable number of virtual I/O daemon modules depending on the number of CPUs supported on the multiprocessor computer system, said virtual I/O daemon modules being capable of processing virtual jobs in parallel.

13. The data storage system according to claim 1, wherein:

said plurality of data storage devices comprises a plurality of disk drives.

14. The data storage system according to claim 1, wherein:

said plurality of data storage devices comprises a plurality of robotic media changer storage devices.

15. The data storage system according to claim 1, wherein:

said plurality of data storage devices comprises a plurality of tape storage devices.

16. In a multiple processor data processing system that includes an I/O subsystem, a data storage system comprising:

a plurality of disk drives;

a physical device driver corresponding to each one of said plurality of disk drives;

a software array driver module for receiving a system I/O request from the I/O subsystem and translating said system I/O request to one or more virtual I/O requests, said one or more virtual I/O requests being provided to one or more of said physical device drivers;

each one of said physical device drivers receiving a virtual I/O request operating to translate said received virtual I/O request into a physical I/O request, said physical I/O request being provided to said disk drive corresponding to said one of said physical device drivers; and

a plurality of virtual I/O daemon modules for communicating with said physical device drivers and said software array driver module wherein;

said software array driver module and said plurality of virtual I/O daemon modules being operative with each of a selected one of a plurality of data storage configurations defined in a group that includes a number of RAID levels;

.

at least one or said virtual I/O daemon modules generating parity, associated with data storage, in parallel with a virtual I/O request from the I/O subsystem that is being processed using said software array driver module;

at least one of said plurality of virtual I/O daemon modules operating in parallel to a first virtual I/O request being processed by said software array driver module to determine an occurrence of an error related to said first virtual I/O request and for processing an error recovery procedure based on the determined error.

17. The data storage system according to claim 16, wherein:

said plurality of virtual I/O daemon modules comprises a tunable number of virtual I/O daemons depending on the number of CPUs supported on the multiple processor data processing system.

18. The data storage system according to claim 16, wherein:

said multiple processor data processing system employs a UNIX operating system; and

said software array driver receives said system I/O request from a UNIX kernal I/O subsystem.

19. A data storage system comprising:

a plurality of data storage devices;

a physical device driver corresponding to each one of said data storage devices;

a software array driver module for receiving a system I/O request and translating said system I/O request into one or more virtual I/O requests, said virtual I/O request being provided to one or more of said physical device drivers;

each one of said physical device drivers receiving a virtual I/O request operating to translate said received virtual I/O request into a physical I/O request, said physical I/O request being provided to said disk drive corresponding to said one of said physical device drivers;

a separate call-back module, different from said physical device drivers, for receiving physical I/O complete signals from said plurality of disk drives and translating said physical I/O complete signals into one or more virtual I/O complete signals corresponding to said one or more virtual I/O requests; and

a separate virtual I/O daemon module., different from said software array driver module, for receiving said one or more virtual I/O complete signals from said call-back module and translating said received virtual I/O complete signals into a system I/O complete signal;

wherein said one or more virtual I/O complete signals are communicated to said virtual I/O daemon module independently of said physical device drivers and said software array driver module.

20. The data storage system according to claim 19, wherein:

said plurality of data storage devices comprises a plurality of disk drives.

21. The data storage system according to claim 19, wherein:

said plurality of data storage devices comprises a plurality of robotic media changer storage devices.

22. The data storage system according to claim 19, wherein:

said plurality of data storage devices comprises a plurality of tape storage devices.