Program execution

VOLIN runs under BS2000 and in the frame of initial installation. Its functionality is also integrated in the SIR utility routine.

The entire range of VOLIN statements (with the exception of a few outdated statements) is now available under SIR in the form of an SDF interface. Therefore, if VIOLIN is called, the old ISP interface will be available; if SIR is called and the appropriate VIOLIN statements are entered, the SDF interface will be available.

This section describes the execution of VOLIN under BS2000. Any differences between this and the initial installation or the version integrated in SIR are described in chapter “SIR Creation of pubsets”. There is also a description of the VOLIN SDF syntax which is integrated in SIR. This manual shows the correspondence between ISP and SDF statements and operands (see "Correspondence between ISP and SDF statements"). Any references to VOLIN statements should be taken to mean ISP statements.

VOLIN uses privileged functions and can run only under the TSOS user ID. Any attempt to execute VOLIN under another user ID results in message NVL0001 and immediate termination of the routine.

VOLIN can be called in an interactive job or in a batch job.
In interactive mode VOLIN handles questions and answers regarding disk initialization via the terminal, otherwise it handles them via the console to which system administration duties have been assigned.

Any number of disks can be initialized in one VOLIN run. Disks are initialized one after the other. Every initialization is controlled by a set of statements read in from SYSDTA. In the event of an error, initialization of the volume currently being processed is terminated. In interactive mode, a new set of statements may then be entered; in a batch job, the VOLIN run is also terminated (TERM MODE=ABNORMAL).

Multiple concurrent VOLIN runs can degrade BS2000 operation. They should therefore be avoided. At the very least, disks to be overwritten should not be accessed via a channel or controller that is also being used for other heavily used disks.

Assignment of volumes

VOLIN requests the disk to be initialized via the system device management facility and reserves it exclusively at its own system.

VOLIN requires at least the specification of the device type or the mnemonic device name (DEVICE and UNIT statements) in order to assign a disk. If a specific disk is to be initialized, VOLIN must be provided with the old volume serial number as well as the disk type the mnemonic device name (via the CHECK statement; see "Description of the statements"). If the volume thus specified is already mounted but not reserved, then it is immediately assigned by device management. If device management cannot reserve the volume specified, VOLIN terminates initialization.

If VOLIN is given only the device type, any disk of this type can be assigned (“scratch volume”). VOLIN uses the SVL to inform system administration about the mounted volume and asks whether the volume may be overwritten. If the answer is YES (i.e. system administration permits overwriting), the mounted disk is initialized. If the answer is negative, three different results are possible:

• Initialization is terminated if the volume is on a fixed-disk device specified with the UNIT statement.

• If no disk device was specified with the UNIT statement, a different disk device is requested.

• If the operator declines to provide another disk when responding to the message from device management, initialization is terminated.

It is possible to specify the mnemonic name instead of the device type. VOLIN then determines the device name from the WORD mnemonic name. The procedure is then the same as when both the device type and mnemonic name are specified.

You must use the mnemonic device name rather than the device type to select a device when running VOLIN from SIR.

It is important to ensure that initialization is coordinated with the work done by other systems that also have access to the device occupied by the volume.

Special features for snap and clone units

Initialization of a snap or clone unit is rejected by VOLIN. When an original unit is initialized using the VOLIN utility routine, VOLIN terminates all snap or clone sessions with this unit as required after an operator query, and possibly those of the SRDF target unit.
This corresponds to /STOP-SNAP-SESSION UNIT=...,SNAP-UNIT=*ALL or /STOP-CLONE-SESSION UNIT=...,CLONE-UNIT=*ALL.