QTAPE or QT

Displays identification, status, and diagnostic information about tape devices. You can request information about a specific tape device or multiple tape devices. The DEVSERV QTAPE command can obtain information from any tape device that is responsive to the SENSEID command. You use two classes of QTAPE parameters to control the scope of the display: unit selection parameters and diagnostic information selection parameters.

Use unit selection parameters to identify the units whose information you want to see. These parameters include ccuu and nnn, LIB, MACH, TYPE, ONLINE, OFFLINE, and DEFINED.
Use diagnostic information selection parameters to define the contents of the display. Beyond the basic status information, you can select which of the following MVS™ system control blocks, and/or what information acquired directly from the following device information buffers, to display in hexadecimal format.
- The system control blocks are UCB and DCE.
  If you specify the NOIO parameter, the display will show only the storage resident information in the requested MVS control blocks; the system will not issue an I/O to the selected device.
- The device information buffers are RDC and RCD.
Any hexadecimal information you request appears in the display following the basic status information.

QTAPE-specific unit selection parameters

The QTAPE-specific unit selection parameters are:

?

Enter the following command to view online help text:

DEVSERV QTAPE,?

ccuu

The number of the starting, or only, tape device you are querying.

nnn

A decimal value indicating the number of sequential device numbers, starting with ccuu, for which to display information.

Valid values for nnn are from 1 to 256. The default is 1. The value must be defaulted (unspecified), or specified with a value of 1, if you are specifying any diagnostic information selection parameters. nnn is valid only when you also specify ccuu.

nnn has a different meaning for DEVSERV QTAPE than for DEVSERV PATHS or DISPLAY UNITS. For those commands, nnn indicates the number of device numbers to display, ignoring gaps in the device number sequence. For the DEVSERV QTAPE command, if gaps exist in the sequence of tape device numbers defined to the operating system, and DEFINED is not specified, the missing tape device numbers are listed in the form '...nnnn(01)...' where nnnn is the device number and 01 is the reason code indicating that no unit control block was found for that device number. If DEFINED is specified, the display contains no information for missing device numbers.

LIB=libid | ALL

Requests information about the devices having the specified libid. If you specify LIB=ALL, the display will show information for all library tape devices. LIB= is mutually exclusive with MACH= and TYPE=.

MACH=mmpp-sssss

A ten-character serial number of either a tape control unit or a tape device. The display will show information for the specific device, or for all devices on the tape control unit having the serial number mmpp-sssss. If you specify the mmpp portion as XXXX, the command processor will ignore the manufacturer and plant of manufacture fields of the serial number, and will search only on sssss, the sequence number portion. MACH is mutually exclusive with LIB and TYPE.

TYPE=type | ALL

Specifies the type of tape device or control unit about which DEVSERV will display information. Valid values for type include any valid four-character tape device or tape control unit number.

TYPE=ALL causes the system to display information for all tape devices that meet all other selection criteria, such as ONLINE, OFFLINE, and DEFINED.

TYPE is mutually exclusive with LIB and MACH.

ONLINE (or ON) and OFFLINE (or OFF)

See the basic status parameters described previously under Parameters.

DEFINED

Displays information about all tape units defined in the current I/O configuration that meet all other selection criteria.

The display contains information based on the existence of unit addresses (UCBs) for tape type devices and not on the existence of physical devices. Therefore, the display may contain information even for unit addresses that have no accessible physical devices, or for which an accessible physical device type is inconsistent with the defined device type.

The system ignores DEFINED if you also specify LIB or MACH, as these options require the existence of a physical device.

If you specify both DEFINED and TYPE=ALL, the display will include information for all tape units defined in the configuration.

If you specify both DEFINED and TYPE=type, where type is other than ALL, the display will include information only for units of the type type. Valid type values are 3400, 3480, 3490, and 3590.

For the 3400 device type, QTAPE supports only the devices that are responsive to the SENSEID command. For other tape devices, QTAPE annotates the display with reason code 9: QTAPE is not supported.

QTAPE diagnostic information selection parameters

Parameters that are only valid when you specify ccuu and nnn, with nnn having a value of 1. The data appears in hexadecimal format. The parameters are:

UCB: Unit control block.
DCE: Device class extension block.
RDC: Read device characteristics block.
RCD: Read configuration data block.
NOIO: No input/output requests.
NOIO calls for a display of processor storage resident information only. The command processor issues no I/O requests to the devices. The display will contain only unit numbers and device types defined in MVS. NOIO is valid only when specified in combination with UCB and DCE. NOIO is mutually exclusive with RDC and RCD, because those parameters can be acquired only via an I/O operation with the device.