US 5,581,724 A · Dynamically mapped data storage subsystem having multiple open destage cylinders and method of managing that subsystem

Abstract

A data storage subsystem dynamically maps a virtual data storage device image presented to associated processors to physical data storage devices used to implement the data storage subsystem. Multiple destage memory elements are concurrently active to increase an aggregate destage data transfer rate and to allow data to be stored on various memory elements appropriate to the type of data contained in each stored virtual object. An open logical cylinder list is used to maintain data integrity among multiple open destage memory elements. Memory elements are also selected to function as archive memory. The data storage subsystem includes a plurality of data storage elements configured into at least two redundancy groups, each redundancy group including n+m of the data storage elements, and a cache memory connected to the redundancy groups and a host processor interface. The data storage subsystem stores data indicative of the amount of available memory space on each of the open logical cylinders and little used data records are migrated or transferred from other memory elements to the archive memory elements to maintain sufficient available memory space.

Claims20

Dependent claims

A data storage subsystem for storing data records for a host processor, which is connected to said data storage subsystem, said data storage subsystem comprising:

a plurality of data storage elements, a number of said data storage elements being configured into a plurality of redundancy groups, each redundancy group including n+m of said plurality of data storage elements, where n and m are both positive integers, with n greater than 1 and m greater than 0 and wherein each redundancy group is divided into a plurality of logical cylinders for storing data;
control unit means comprising:
at least one multipath storage director means for interconnecting said host processor with said data storage subsystem,
cache memory means connected to and interconnecting said at least one multipath storage director means and said redundancy groups;
processor means for maintaining a plurality of said logical cylinders concurrently open to write data from said cache memory means to a selected one of the plurality of concurrently open logical cylinders, wherein said processor is responsive to receipt of data records from said host processor, for selecting, independent of said host processor, available memory space in one of said plurality of concurrently open logical cylinders to store the received data records;
and
disk drive manager means for writing the received data records and data redundancy information for the received data records from said cache memory means into the selected available memory space.

4 more elements

A method of storing data records in redundancy groups in a data storage system which is connected to a host processor via a processor interface and having a plurality of data storage elements for storing data thereon, a number of said data storage elements being configured into at least two redundancy groups, each redundancy group including n+m of said plurality of data storage elements, where n and m are both positive integers with n greater than 1 and m greater than 0, wherein each redundancy group is divided into a plurality of logical cylinders for storing data, and further including a cache memory connected to said processor interface and said redundancy groups, said method comprising the steps of:

maintaining a plurality of said logical cylinders concurrently open to write data from said cache memory to a selected one of the plurality of concurrently open logical cylinders;
selecting, in response to receipt of data records from said host processor, independent of said host processor, available memory space in one of said plurality of concurrently open logical cylinders to store the received data records;
and
writing the received data records and data redundancy information for said received data records in the selected available memory space.

1 more element

Dependencies are inferred from the claim text.

Dynamically mapped data storage subsystem having multiple open destage cylinders and method of managing that subsystem

Life of this patent

Dynamically mapped data storage subsystem having multiple open destage cylinders and method of managing that subsystem

Life of this patent

Abstract

Claims20