Browse Prior Art Database

Mass Storage System Control Table Analysis

IP.com Disclosure Number: IPCOM000085424D
Original Publication Date: 1976-Apr-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 3 page(s) / 41K

Publishing Venue

IBM

Related People

Frender, WD: AUTHOR [+3]

Abstract

A mass storage system (MSS) serving a primary host and a plurality of other hosts via mass storage control (MSC) and director staging adapters (DIRSA), has need for verifying that control tables used throughout the MSS and the host require a high degree of identicalness to achieve MSS operations. The MSS components include a mass storage facility (MSF) controlled by MSC.

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Mass Storage System Control Table Analysis

A mass storage system (MSS) serving a primary host and a plurality of other hosts via mass storage control (MSC) and director staging adapters (DIRSA), has need for verifying that control tables used throughout the MSS and the host require a high degree of identicalness to achieve MSS operations. The MSS components include a mass storage facility (MSF) controlled by MSC.

The MSF stages data to and receives destaged data from a disk storage facility (DSF) via a staging adapter portion of one of several DIRSA's. Each MSF has a plurality of read/write units capable of automatically receiving and exchanging data signals with a large multiplicity of data cartridges, automatically storable in one of a multiplicity of storage cells. Each data cartridge is assigned uniquely to one and only one storage cell.

The table verification consists of steps which are detailed later. First, the MSC control tables are compared to ensure that the various tables controlled and accessed by MSC all contain consistent entries. In this regard, MSC has a plurality of tables for different purposes. Next, the MSC and DIRSA tables are compared for consistency. Finally, the MSC and host tables are compared. In this regard, the host has a mass storage volume control (MSVC) having an inventory data set table mass storage volume inventory (MSVI), which reflects the status of the MSS for controlling host requests to MSC.

Each of the tables contains inventory and control information. accordingly, information contained in the various control tables is duplicated or otherwise logically interrelated. The software program of the present description analyzes related information between and within these tables and identifies any detected inconsistencies. For example, MSC and DIRSA tables both contain information about allocated pages of staging space within DSF. Such allocations should be identically identified within MSC and the appropriate DIRSA.

Similarly, the MSC control tables and MSVC inventory MSVI are verified for consistency. The checking performed is particularly useful to avoid dumping all system control program signals; the checking enables an analysis for isolating an error-causing problem in MSS. For each MSS, there are DIRSA tables for each DIRSA, and one primary set of MSC tables and MSVC tables.

The software program obtains a copy of the MSC tables and all of the DIRSA tables. Such acquisition prevents the changing of tables during the pro...