Method for configuring a single hardware I/O control block architecture for use with both mirrored and non-mirrored data transfers

• US 6,871,238 B1
• Filed: 02/12/2004
• Issued: 03/22/2005
• Est. Priority Date: 01/16/2002
• Status: Expired due to Term

• Current Assignee: PMC-Sierra Incorporated (Microchip Technology Incorporated)
• Original Assignee: Adaptec Incorporated (Steel Partners Holdings LP)
• Inventors: Young, B. Arlen
• Primary Examiner(s): Gaffin, Jeffrey
• Assistant Examiner(s): NGUYEN, TANH Q
• Application Number:
  US10/779,416
• Time in Patent Office: 404 Days
• Field of Search: 710/5, 710 8- 10, 710/14, 710/20, 710/24, 710/39, 710/62, 710/64, 710/72, 710/74, 714/1, 714/6, 707/204, 711/100, 711/114, 711/161, 711/162
• US Class Current: 710/5
• CPC Class Codes: G06F 11/2087 with a common controller
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

A single host adapter hardware I/O control block contains information used to specify a transfer of data from a host system to a first target device and in addition information that specifies whether the data is to be mirrored, and if so, optionally identifies a second target device on which the data is to be mirrored. After transferring the single hardware I/O control block to the host adapter integrated circuit, the host adapter integrated circuit determines whether the hardware I/O control block specifies a mirrored transaction. If a mirrored transaction is specified, the host adapter integrated circuit generates a second hardware I/O control block for the second target device using the information in the first hardware I/O control block. When the execution of both hardware I/O control blocks is complete, the host adapter integrated circuit provides a single completion notification to the host system.

Claims

1. A method comprising:

using, in a host system, a single hardware I/O command block structure for both non-mirrored and mirrored transactions for a plurality of target devices coupled to said host system by a host adapter wherein said single hardware I/O block structure includes one of a read command for a read transaction and a write command for a write transaction to be executed by a target device;

setting a mirror field in said single hardware I/O command block structure to a valid value for a mirrored transaction; and

setting said mirror field in said single hardware I/O command block structure to an invalid value for a non-mirrored transaction.

2. The method of claim 1 further comprising:

setting a target identification field in said single hardware I/O command block structure to identify one of said plurality of target devices when said mirror field in said single hardware I/O command block structure is set to said valid value for said mirrored transaction.

3. The method of claim 1 wherein said valid value comprises a valid hardware I/O control block identification number.

4. The method of claim 1 wherein said invalid value comprises a null identification number.

5. The method of claim 1 wherein said mirrored transaction comprises a write transaction.

6. The method of claim 1 wherein said mirrored transaction comprises a read transaction.

7. A system comprising:

a host adapter;

a plurality of target devices coupled to said host adapter; and

a host system coupled to said host adapter, said host system comprising a memory having stored therein instructions for a method wherein upon execution of said instructions by said host system, said method comprises;

using, in said host system, a single hardware I/O command block structure for both non-mirrored and mirrored transactions for a said plurality of target devices coupled to said host system by a said host adapter wherein said single hardware I/O block structure includes one of read command for a read transaction and a write command for a write transaction to be executed by a target device;

setting a mirror field in said single hardware I/O command block structure to a valid value for a mirrored transaction; and

setting said mirror field in said single hardware I/O command block structure to an invalid value for a non-mirrored transaction.

8. The system of claim 7 wherein said method further comprises:

setting a target identification field in said single hardware I/O command block structure to identify one of said plurality of target devices when said mirror field in said single hardware I/O command block structure is set to said valid value for said mirrored transaction.

9. The system of claim 7 wherein said valid value comprises a valid hardware I/O control block identification number.

10. The system of claim 7 wherein said invalid value comprises a null identification number.

11. The method of claim 7 wherein said mirrored transaction comprises a write transaction.

12. The method of claim 7 wherein said mirrored transaction comprises a read transaction.