System for allocating storage spaces based upon required and optional service attributes having assigned piorities

• US 5,287,500 A
• Filed: 06/03/1991
• Issued: 02/15/1994
• Est. Priority Date: 06/03/1991
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Digital Equipment Corporation (HP Inc.)
• Inventors: Stoppani, Peter Jr.
• Primary Examiner(s): Lee, Thomas C.
• Application Number:
  US07/709,626
• Time in Patent Office: 988 Days
• Field of Search: 395/700, 395/200, 395/600, 395/800, 395/425
• US Class Current: 711/211
• CPC Class Codes: G06F 16/10 File systems; File servers
• 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
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99956 File allocation

Abstract

A computer file system, for use with a computer system having a multiplicity of distinct data storage devices, includes a management program that defines a set of service attributes which characterize operational characteristics of data storage devices. A service class table stores data denoting which of service attributes characterize each distinct storage device. The management program adds data to the service class table when additional data storage devices are added to the computer system. A storage device selection program responds to file allocation requests, which specify a set of service attributes, by comparing the specified set of service attributes with the data stored in the service class table and selecting one of the data storage devices in accordance with predefined service attribute matching criteria. The service attributes used by the file system may include required service attributes and optional service attributes. In that case, the predefined service attribute matching criteria include criteria requiring that the required service attributes of the selected data storage device, as denoted in the service class table, match all required service attributes specified in the corresponding file allocation request. In addition, there are predefined criteria for maximizing matching of specified optional service attributes with the optional service attributes of the selected data storage device.

Claims

1. A file system for use with a computer system having a multiplicity of distinct data storage devices, comprising:

service class table means for storing data, including a plurality of service class values, each service class value designating a separate service class;

wherein each said service class value comprises a set of N (where N>

3) binary values associated with at least one of said distinct storage devices;

schema means for characterizing operational characteristics of data storage devices with a set of service attributes, and for associating each service attribute with a selected one of said N binary values in each said service class value;

said service attributes including required service attributes and optional service attributes wherein said optional service attributes have assigned priorities;

said service class table means denoting which of said required service attributes and which of said optional service attributes are applicable to each of said distinct storage devices;

supplementing means, coupled to said service class table means and said schema means, for adding data to said service class table means when additional data storage devices are added to said computer system;

usage status means for providing space availability data indicating availability of space in each said storage device for storing additional files; and

storage device selection means, coupled to said service class table means and said usage status means, for responding to file allocation requests specifying a requested service class value, said requested service class value specifying a set of required service attributes and a set of optional service attributes, by comparing said requested service class value with said data stored in said service class table means and selecting one of said data storage devices in accordance with predefined service class value matching criteria;

said predefined service attribute matching criteria used by said storage device selection means including criteria requiring that said space availability data in said usage status means indicate sufficient available space in the selected data storage device to store an additional file;

wherein said predefined service attribute matching criteria used by said storage device selection means include criteria requiring that the required service attributes of the selected data storage device, as denoted in the service class table means, match all required service attributes specified by said requested service class value, as well as criteria for selecting a data storage device with optional service attributes, as denoted in the service class table means, which most closely matches said optional service attributes specified in said file allocation request in accordance with said assigned priorities if a plurality of said data storage devices have the required service attributes specified in said file allocation request.

2. A method of allocating storage space in a computer system having a multiplicity of distinct data storage devices, comprising the steps of:

defining a set of service attributes that categorize the operational characteristics of said data storage devices;

said service attributes including required service attributes and optional service attributes wherein said optional service attributes have assigned priorities;

storing in a computer memory a service class table of data, including a plurality of service class values, indicating which of said required service attributes and which of said optional service attributes are applicable to each of said distinct storage devices;

wherein each said service class value comprises a set of N (where N>

3) binary values associated with at least one of said distinct storage devices and each of said binary values is associated with one of said service attributes;

adding data to said service class table when additional data storage devices are added to said computer system, adding to said service class table data indicating which of said service attributes are applicable to said additional storage device;

storing and maintaining space availability data indicating availability of space in each said storage device for storing additional files; and

responding to a file allocation request specifying a set of service attributes by comparing said specified set of service attributes with said data stored in said service class table and selecting one of said data storage devices in accordance with predefined service attribute matching criteria;

said specified set of service attributes in said file allocation request including specified required service attributes and specified optional service attributes;

said predefined service attribute matching criteria including criteria requiring that said space availability data indicate sufficient available space in the selected data storage device to store an additional file;

said predefined service attribute matching criteria including criteria requiring that the required service attributes of the selected data storage device, as indicated by the data in the service class table, match all required service attributes specified in said file allocation request, as well as criteria for for selecting a data storage device with optional service attributes, as indicated by the data in the service class table, which most closely matches said optional service attributes specified in said file allocation request in accordance with said assigned priorities if a plurality of said data storage devices have the required service attributes specified in said file allocation request.