Storage management system and auto-RAID transaction manager for coherent memory map across hot plug interface

• US 6,230,240 B1
• Filed: 06/23/1998
• Issued: 05/08/2001
• Est. Priority Date: 06/23/1998
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Shrader, Steven L., Rust, Robert A.
• Primary Examiner(s): Gossage, Glenn
• Application Number:
  US09/103,329
• Time in Patent Office: 1,050 Days
• Field of Search: 711/114, 711/113, 711/112, 711/161, 711/162, 714/5, 714/6, 714/7, 710/129, 710/103, 710/245, 710/39, 710/54
• US Class Current: 711/114
• CPC Class Codes: G06F 11/2089 Redundant storage control functionality
• CPC Class Codes: G06F 11/2097 maintaining the standby controller/processing unit updated initialisation or re-synchronisation thereof G06F11/1658 and subgroups
• CPC Class Codes: G06F 2201/82 Solving problems relating to consistency
• 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 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: G11B 20/10 Digital recording or reproducing

Abstract

A storage management system for a Redundant Array of Independent Disks (RAID) data storage system and an AutoRAID memory transaction manager for a disk array controller are disclosed. The disk array controller enables a consistent, coherent memory image of the data storage space to all processors across hot-plug interfaces. To external processes seeking to read or write data, the memory image looks the same across the hot-plug interface. The disk array controller has two identical controllers, each with its own non-volatile memory, to maintain redundant images of disk array storage space. A hot-plug interface interconnects the two controllers. Each controller has an AutoRAID memory transaction manager that enables sharing of cyclic redundancy check (CRC)-protected memory transactions over the hot-plug interface between the two controllers. The AutoRAID memory transaction managers also have transaction queues which facilitate ordered execution of the memory transactions regardless of which controller originated the transactions. The AutoRAID transaction manager includes first and second bus interfaces, a mirror entity, and a local memory interface. Mirrored read and write transactions are handled atomically across the hot-plug interface.

Claims

1. A storage management system for a redundant array of independent disks (RAID) data storage system, comprising:

at least two controllers interconnected via a hot-plug interface, each controller having a non-volatile memory to store redundant images of storage space provided by the data storage system;

each controller further having a memory transaction manager that orders memory transactions involving its non-volatile memory and facilitates transmission and receipt of the memory transactions over the hot-plug interface, wherein each memory transaction manager comprises;

a transbus entity to control a multiple access bus;

a first bus interface to receive memory transactions from a bus and to post the memory transactions on the access bus;

a mirror entity coupled to the access bus to handle the memory transactions received by the first bus interface, the mirror entity ordering the memory transactions;

a local memory interface coupled to the access bus to receive the memory transactions from the mirror entity and to execute the memory transactions with respect to a local non-volatile memory; and

a second bus interface coupled to the access bus to facilitate transfer of the memory transactions to a remote mirrored memory in a different one of the controllers.

2. A storage management system as recited in claim 1, wherein the redundant images stored by the non-volatile memories of the controllers appear identically across the hot-plug interface to external processes seeking to read or write data.

3. A storage management system as recited in claim 1, wherein each memory transaction manager exchanges the memory transactions in cyclic redundancy check (CRC)-protected packets to guarantee valid transfer.

4. A storage management system as recited in claim 1, wherein each memory transaction manager comprises a transaction queue to order the memory transactions.

5. A storage management system as recited in claim 1, wherein the memory transaction managers perform the memory transactions for respective ones of the non-volatile memories in an atomic manner.

6. A storage management system as recited in claim 1, wherein the controllers designate one of the memory transaction managers as having primary responsibility of ordering the memory transactions for all of the controllers.

7. An AutoRAID memory transaction manager for a disk array controller having a non-volatile memory to store redundant images of storage space provided by a data storage system, the disk array controller interconnected to a second disk array controller via a hot-plug interface, the memory transaction manager facilitating transmission and receipt of memory transactions involving the non-volatile memory over the hot-plug interface and, the memory transaction manager comprising:

a transbus entity to control a multiple access bus;

a first bus interface to receive the memory transactions from a bus and to post the memory transactions on the access bus;

a mirror entity coupled to the access bus to handle the memory transactions received by the first bus interface, the mirror entity ordering the memory transactions;

a local memory interface coupled to the access bus to receive the memory transactions from the mirror entity and to execute the memory transactions with respect to the non-volatile memory; and

a second bus interface coupled to the access bus to facilitate transfer of the memory transactions to a remote mirrored memory in the second disk array controller.

8. An AutoRAID memory transaction manager as recited in claim 7, wherein the mirror entity comprises a transaction queue to hold the memory transactions in an order.

9. An AutoRAID memory transaction manager as recited in claim 7, wherein the second bus interface packages the memory transactions as one or more packets and computes an error correction value for the one or more packets.

10. An AutoRAID memory transaction manager as recited in claim 7, wherein the AutoRAID memory transaction manager is formed on an integrated circuit chip.

11. A disk array controller for an AutoRAID data storage system, comprising:

multiple controllers having respective memories that store redundant memory maps, each controller being equipped with an AutoRAID memory transaction manager to manage memory transactions involving a first controller having a local non-volatile memory with respect to a second controller having a remote mirrored memory, each AutoRAID memory transaction manager comprising;

a transbus entity to control a multiple access bus;

a first bus interface to receive memory transactions from a bus and to post the memory transactions on the access bus;

a mirror entity coupled to the access bus to handle the memory transactions received by the first bus interface, the mirror entity ordering the memory transactions;

a local memory interface coupled to the access bus to receive the memory transactions from the mirror entity and to execute the memory transactions with respect to the local non-volatile memory in the first controller; and

a second bus interface coupled to the access bus to facilitate transfer of the memory transactions to the remote mirrored memory in the second controller.