US 5,963,971 A · Method and apparatus for handling audit requests of logical volumes in a virtual media server

Abstract

In a data storage subsystem a virtual removable media server (VRMS) handles host audit requests, whether directed to a physical volume or a virtual volume physically stored in cache or in a removable physical media item. The subsystem includes a storage interface between the host and data storage facilities including a cache and a physical media library. To the host, the storage interface emulates a virtual library including a plurality of virtual media items, each containing a logical volume of data. The library may also maintain physical media items each storing one logical volume, as in a traditional library. To verify presence of a specified logical volume of the virtual library, the host sends an audit request. Responsively, the subsystem cross-references the specified logical volume in a first list to identify physical locations of underlying data. This physical location may be an address in the cache and/or a physical volume corresponding to a physical media item in the library. If the underlying data is stored exclusively in cache, the subsystem automatically answers affirmatively to the audit request. If the underlying data is stored in the physical media, the subsystem searches the library for the physical media item containing the physical volume that includes the specified logical volume, and answers the audit request affirmatively if the physical media item is found. If the physical media item is not found, the subsystem answers the audit request negatively.

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Claims48

Dependent claims

A method of handling audit requests received by a data storage subsystem from a host, the data storage subsystem including a storage interface between the host and data storage facilities including a direct-access storage device (DASD) cache and a physical media library, where the storage interface in communicating with the host emulates a virtual library including a plurality of virtual media items each containing a logical volume of data, the method comprising the steps of:

receiving from the host an audit request comprising a request to verify presence of a specified logical volume of the virtual library;
identifying physical locations of the specified logical volume, the physical locations comprising at least one of the following:
the DASD cache, if the logical volume is stored in the DASD cache;
and
a physical volume corresponding to a physical media item in the physical media library, if the logical volume is stored in the physical media library;
and
if the identified physical locations include the DASD cache exclusively, providing an affirmative output to the audit request;
and
if the identified physical locations include the physical media library, searching the physical media library for the physical media item containing the physical volume that includes the specified logical volume, and providing an affirmative output to the audit request if the physical media item is found, otherwise, providing a negative output to the audit request.

6 more elements

receiving from the host an audit request comprising a request to verify presence of a specified volume of the virtual library;
if the specified volume is a physical volume corresponding to a physical media item in the library, conducting a search of the physical media library for the physical media item and providing an affirmative output to the audit request if the physical media item is found, otherwise, providing a negative output to the audit request;
and
if the specified volume is a logical volume, performing steps comprising:
identifying physical locations of the specified logical volume, the physical locations comprising at least one of the following:
the DASD cache, if the logical volume is stored in the DASD cache;
and
a physical volume corresponding to a physical media item in the physical media library, if the logical volume is stored in the physical media library;
and
if the identified physical locations include the DASD cache exclusively, providing an affirmative output to the audit request;
and
if the identified physical locations include the physical media library, searching the physical media library for the physical media item containing the physical volume that includes the specified logical volume, and providing an affirmative output to the audit request if the physical media item is found, otherwise, providing a negative output to the audit request.

9 more elements

A signal-bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform a method for handling audit requests submitted by a host to a data storage subsystem, the data storage subsystem including a storage interface between the host and data storage facilities including a direct-access storage device (DASD) cache and a physical media library, where the storage interface in communicating with the host emulates a virtual library including a plurality of virtual media items each containing a logical volume of data, the method comprising the steps of:

receiving from the host an audit request comprising a request to verify presence of a specified logical volume of the virtual library;
identifying physical locations of the logical volume, the physical locations comprising:
the DASD cache, if the logical volume is stored in the DASD cache;
and
a physical volume corresponding to a physical media item in the physical media library, if the logical volume is stored in the physical media library;
and
if the identified physical locations include the DASD cache exclusively, providing an affirmative output to the audit request;
and
if the identified physical locations include the physical media library, searching the physical media library for the physical media item containing the physical volume that includes the specified logical volume, and providing an affirmative output to the audit request if the physical media item is found, otherwise, providing a negative output to the audit request.

6 more elements

receiving from the host an audit request comprising a request to verify presence of a specified volume of the virtual library;
if the specified volume is a physical volume corresponding to a physical media item in the library, conducting a search of the physical media library for the physical media item and providing an affirmative output to the audit request if the physical media item is found, otherwise, providing a negative output to the audit request;
and
if the specified volume is a logical volume, performing steps comprising:
identifying physical locations of the logical volume, the physical locations comprising at least one of the following:
the DASD cache, if the logical volume is stored in the DASD cache;
and
a physical volume corresponding to a physical media item in the physical media library, if the logical volume is stored in the physical media library;
and
if the identified physical locations include the DASD cache exclusively, providing an affirmative output to the audit request;
and
if the identified physical locations include the physical media library, searching the physical media library for the physical media item containing the physical volume that includes the specified logical volume, and providing an affirmative output to the audit request if the physical media item is found, otherwise, providing a negative output to the audit request.

9 more elements

A data storage subsystem, comprising:

data storage facilities including:
a direct access storage device (DASD) cache;
and
a physical media library including a library manager;
and
a storage interface interconnected between a host and the data storage facilities, where the storage interface in communicating with the host emulates a virtual library including a plurality of virtual media items each containing a logical volume of data;
wherein the storage interface and library manager are programmed to perform a method for handling audit requests received from the host, the method comprising:
receiving from the host an audit request comprising a request to verify presence of a specified logical volume of the virtual library;
identifying physical locations of the logical volume, the physical locations comprising:
an address in the DASD cache, if the logical volume is stored in the DASD cache;
and
a physical volume corresponding to a physical media item in the physical media library, if the logical volume is stored in the physical media library;
and
if the identified physical locations include the DASD cache exclusively, providing an affirmative output to the audit request;
and
if the identified physical locations include the physical media library, searching the physical media library for the physical media item containing the physical volume that includes the specified logical volume, and providing an affirmative output to the audit request if the physical media item is found, otherwise, providing a negative output to the audit request.

13 more elements

A data storage subsystem, comprising:

data storage facilities including:
a direct access storage device (DASD) cache;
and
a physical media library including a library manager;
and
a storage interface interconnected between a host and the data storage facilities, where the storage interface in communicating with the host emulates a virtual library including a plurality of virtual media items each containing a logical volume of data;
wherein the storage interface and library manager are programmed to perform a method for handling audit requests received from the host, the method comprising:
receiving from the host an audit request comprising a request to verify presence of a specified volume of the virtual library;
if the specified volume is a physical volume corresponding to a physical media item in the library, conducting a search of the physical media library for the physical media item and providing an affirmative output to the audit request if the physical media item is found, otherwise, providing a negative output to the audit request;
and
if the specified volume is a logical volume, performing steps comprising:
identifying physical locations of the logical volume, the physical locations comprising at least one of the following:
the DASD cache, if the logical volume is stored in the DASD cache;
and
a physical volume corresponding to a physical media item in the physical media library, if the logical volume is stored in the physical media library;
and
if the identified physical locations include the DASD cache exclusively, providing an affirmative output to the audit request;
and
if the identified physical locations include the physical media library, searching the physical media library for the physical media item containing the physical volume that includes the specified logical volume, and providing an affirmative output to the audit request if the physical media item is found, otherwise, providing a negative output to the audit request.

16 more elements

Dependencies are inferred from the claim text.

Description5,146 words

Summary1,162 words

#1. Field of the Invention

#The present invention relates to digital data storage systems. More particularly, the invention concerns a data storage subsystem comprising a virtual removable media server (VRMS) that handles audit requests, whether directed to a physical volume or a virtual volume physically stored in cache or in a removable physical media item.

#2. Description of the Related Art

Brief description of the drawings5 figures

#The nature, objects, and advantages of the invention will become more apparent to those skilled in the art after considering the following detailed description in connection with the accompanying drawings, in which like reference numerals designate like parts throughout, wherein:

#FIG. 1 is a block diagram of the hardware components and interconnections of a VRMS in accordance with the invention.

#FIG. 2 is a block diagram of a digital data processing machine in accordance with the invention.

Detailed description3,845 words

#One aspect of the invention concerns a data storage subsystem providing a virtual removable media storage function, which also handles audit requests of logical volumes. FIG. 1 depicts the various hardware components and interconnections of one example of this subsystem.

#Subsystem Components

#Generally

Facts

Application

08/948,366Filed 9 Oct 1997

Granted

5 Oct 1999

Term ended

9 Oct 2017

Estimated · how

20 years from earliest known nonprovisional domestic filing. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination. Patent term adjustment is unavailable; no adjustment was added.

Classification6 codes

G06F 3/0607
Improving or facilitating administration, e.g. storage management: by facilitating the process of upgrading existing storage systems, e.g. for…
G06F 3/0634
Configuration or reconfiguration of storage systems: by changing the state or mode of one or more devices
G06F 3/0686
Plurality of storage devices: libraries, e.g. tape libraries, jukebox
G06F 12/0866
Addressing of a memory level in which the access to the desired data or data block requires associative addressing means, e.g. caches: for…

Method and apparatus for handling audit requests of logical volumes in a virtual media server

Life of this patent

Method and apparatus for handling audit requests of logical volumes in a virtual media server

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims48

Description5,146 words

Drawings

Classification6 codes

Life of this patent

Description5,146 words