IBM Magstar 3494 manual Component Availability, Refresh

Port Initialization shows status of the tape subsystem control unit ports and direct attach ports. It indicates whether a port is a Direct Attach or Control unit port. It indicates Initialized, Not initialized, or Not installed.

The Operational Status window has the following pull-downs available from its action bar:

Refresh

Immediately refreshes or updates the contents of the window. The window is periodically refreshed; however, clicking the pointing device on the selection area of the window causes an immediate update of the window.

Help Provides help about the items in the window.

To close the window, select Close from the system menu icon (upper-left corner of the window).

Component Availability

The library manager keeps track of which components are available so that it can make the best use of the available hardware when processing commands. When a component fails, the component is automatically marked unavailable for use. The library manager does not use the component (for example, a 3490E/3590 drive) until it is marked available via the Service menu on the library manager console.

The availability status of all the library components can be displayed on the library manager console. Availability information is kept in the library manager database so that it is not lost if the library manager is shutdown.

Drives can be marked on the library manager as available or unavailable. If a drive is available, it is available to the cartridge accessor. If the drive is marked unavailable, the drive is not available to the cartridge accessor.

Note: Device availability or unavailability is independent of the drive status (Online or Offline) with the host.

A drive is marked unavailable when something prevents the cartridge accessor from going to that drive, for example, the drive is being serviced. Even if no host requests are made for the drive, the library manager may try to clean a drive if it is available.

Device availability is not checked when host requests are received and validated because the drive availability can change between the time the command is accepted and the time the request is executed. If a host request is accepted and the required drive is marked as unavailable when it is time to execute the request, the request fails. Conversely, if the required drive is unavailable at request acceptance but is made available before the request executes, the request completes normally.

Figure 64 on page 116, Figure 65 on page 117, and Figure 66 on page 117 show the Component Availability Status windows.

Chapter 6. Advanced Operating Procedures 115