StorageTek 6 manual HSC Subsystem Components, HSC Architecture

HSC Subsystem Components

The HSC is a secondary subsystem that executes in various environments including a standard class G virtual machine. The HSC contains the following components:

•External Components — External components interface with other virtual machines, an operator, an administrator, and/or a system programmer. The external components consist of an installation component, the initialization/termination component, a command component, the utility component, and a tape management interface component.

•Common Components — Common components provide distinct functions required by the external and common components. The common components consist of the mount/dismount components, the CAP component, and the recovery component.

•Control Components — Control components provide logical control over system entities used by both common components and external components. The control components consist of the volume/cell control component and the configuration control component.

•Server Components — The server components provide physical control of system entities for the control components. The server components consist of the data base server, the LMU server, the WTO component, and the address space communications server.

HSC Architecture

Note: In this discussion, address space refers to a virtual machine.

Figure 1 on page 5 displays external components located in the user’s address space on the left side, and other HSC components located in the HSC’s address space on the right side.

Note: The initialization/termination external component resides entirely in the HSC address space.

The Address Space Communications Server spans the user’s address space and the HSC address space. It handles requests from components in the user’s address space that require services from components located in the HSC’s address space.

The following section briefly describes the functions of each external component.

Operator Command component

The operator command component receives control from other virtual machines to process an HSC command or to call upon services in the HSC.

Batch Utilities external component

The utility component exists mostly within the service machine. However, a few utilities execute in the invoker’s CMS virtual machine.

4VM/HSC 6.0 System Programmer’s Guide

1st ed., 6/30/04 - 312579601