gtpo1m0m | Operations |
This section describes the TPF system tape support. It includes information about the following:
The TPF system addresses tapes by 3-character symbolic names. The ZTLBL command creates the 3-character symbolic name. The ZTMNT command assigns the tape name to a physical device and records the assignment in the tape status table (TSTB). These symbolic tape names are used by tape macros to access tapes.
All system tapes except ALT tapes must be standard label (SL) tapes. All output tapes are also standard label tapes. Unlabeled input tapes are nonlabel (NL) tapes. Use ZTLBL parameters LSL, LSU, or LNL to define the label attributes for a symbolic tape name. See ZTLBL-Tape Label Maintenance for more information.
The following identifies the symbolic tape names that are reserved by the
TPF system. Applications can use all other 3-character alphanumeric
labels for symbolic tape names.
Automatic tape mounting allows the TPF system to perform the following tasks without operator intervention:
You determine the tapes that can be mounted on specific tape devices by defining tape groups, assigning tape labels (names) to the tape groups, and assigning tape devices to the tape groups. When a tape device is enabled for automatic tape mounting, the TPF system automatically mounts an ALT tape if an expired, write-enabled tape is loaded on the tape device. If the TPF system needs an active or standby tape, it searches for an eligible ALT tape and converts the tape.
To use automatic tape mounting, you must do the following:
After you define the tape groups, you can do the following:
Tape groups determine whether an ALT tape on a particular tape device can be used to satisfy a tape open or tape switch request for a particular tape label. By grouping tape labels and assigning tape devices to various tape groups, you can direct tape output without manually mounting active and standby tape pairs. You can also control the scope of the tape assignment to a single subsystem user or to all subsystem users.
One or more tape devices can be assigned to a tape group, and 1 or more tape labels can be assigned to a tape group. To use a tape group, you must do the following:
A tape group is specific to a processor. Therefore, you can use the same tape group name on different processors. The ALL and NONE tape groups are already defined by the TPF system and, therefore, cannot be specified as unique tape group names. Use the ALL tape group name to indicate that a tape device is assigned to all tape groups. Use the NONE tape group name to indicate that a tape label is not assigned to any tape group.
When you assign a tape device to a tape group, you choose the scope of the assignment:
Each tape device can be assigned to a maximum of 31 tape groups, one of which can be the ALL tape group.
If you place a tape device offline and then bring it back online (using the ZTVAR command), the tape group assignments for that tape device are retained.
When you assign a tape label to a tape group, the assignment is made for the subsystem user in which the tape label is defined. The tape label is also associated with the tape devices assigned to that same tape group. In this case, the subsystem user assignment depends on how it was defined for the tape devices. For example, if the tape devices were assigned to the tape group for all subsystem users, the tape label is also associated with all the subsystem users when the tape is mounted on those tape devices.
You can define a maximum of 254 tape groups for each processor. The same tape label can be assigned to different tape groups across different subsystem users. For example, you can assign the TAP tape label to the GENERAL tape group in the SSU1 subsystem user and also assign it to the XYZ tape group in the SSU2 subsystem user.
A tape device can be:
To determine what you should do with your tape devices, consider whether or not you need to direct your output to specific tape devices.
After a tape device is enabled for automatic tape mounting, the TPF system can automatically mount a tape as an ALT tape when a tape is loaded on the tape device and the tape device is ready. The tape is not mounted as an ALT tape if any of the following conditions are true:
When an ALT tape is automatically mounted, it is mounted in the format that the tape was last recorded.
If you enable automatic mounting for a tape device that is ready and has a tape loaded but not mounted, the same process is performed that would have been performed if the tape had been loaded and the tape device had been ready. The tape is then mounted as an ALT tape as long as none of the conditions that prevent automatic tape mounting are true.
Use the ZTDEV command to enable, disable, or resume automatic tape mounting for a tape device.
Use the ZTGRP command to display or delete tape groups.
You cannot delete a tape group if a tape label that is defined for an active subsystem user is assigned to that tape group.
If a tape device is assigned to a tape group when you delete it, the tape device is unassigned from that tape group.
During tape restart for a hardware initial program load (IPL) or a nonfast IPL, all tape labels for all active subsystem users are checked to ensure that they do not refer to any tape groups that were deleted while the subsystem user may have been inactive. Any tape label that is assigned to a deleted tape group is reassigned to the NONE tape group.
Use the ZTDEV command to display the tape groups to which a tape device is assigned in the current subsystem user. The status of automatic tape mounting for a tape device is also displayed.
Use the ZTLBL command to assign a tape label to a new tape group or to unassign a tape label from a tape group.
Knowing the search priorities used by the TPF system during automatic tape mounting can help when you define your tape groups. The TPF system uses one set of priorities for tape switching and ALT tape conversion and another set of priorities for macro processing.
If there is no appropriate standby tape during a tape switch, the TPF system tries to locate an appropriate ALT tape by using the following search priorities:
If an appropriate ALT tape is found, it is converted to the appropriate standby tape and the tape switch continues. If no appropriate ALT tape is found, you are prompted to mount the appropriate standby tape.
If a TOURC, TOUTC, TOPNC, or TSYNC macro is called and there is no appropriate active tape, the TPF system tries to locate an appropriate ALT tape by using the following search priorities:
If an appropriate ALT tape is found, the tape is converted to the appropriate active tape and the macro is called again. If no appropriate ALT tape is found, you are prompted to mount the appropriate active tape. When you are prompted to mount a tape (that is, no appropriate ALT tape was found), you can do one of the following:
The tape library dataserver allows you to load and unload tapes without operator intervention. The library manager controls all automated library operations in the tape library dataserver. Many automated library operations, especially setup operations, must be performed at the library manager. See the appropriate tape library dataserver operator's guide for more information about these automated library operations.
Once the tape library dataserver is set up and a tape device in the TPF system is attached to the tape library dataserver, you can control automated library operations from the TPF system by using the ZTPLF commands.
When you enter the ZTPLF commands, you indicate which tape library dataserver you want to use by specifying the address of a tape device that is attached to the appropriate tape library dataserver. Any number of tape library dataservers can be set up for a host system. However, a tape device can be attached to only one tape library dataserver.
It is important to understand the concept of tape library categories when discussing automated library operations. Tape library categories are groups of tapes that have common attributes; for example, tapes to eject, tapes that are new to the tape library dataserver, and tapes that are used to clean tape devices. These tape library categories identify how to use the tape and where to put it. For example, tapes that are added to the convenience-eject category have a status of eject pending. The tape library dataserver moves these tapes to a convenience output station.
The following information describes the tape library categories:
Category | Description |
|
---|---|---|
X'0000' | Null | |
X'0001'-X'FEFF' | General use | |
X'FF00'-X'FFFF' | Reserved for automated library operations | |
X'FF00' | Insert | |
X'FF10' | Convenience-eject | |
X'FF11' | Bulk-eject (if the hardware is installed) | |
X'FFF9' | Service-tape | |
X'FFFA' | Manually-ejected | |
X'FFFB' | Purge-tape | |
X'FFFC' | Unexpected-tape | |
X'FFFD' | Unknown-tape | |
X'FFFE' | Cleaner-tape | |
X'FFFF' | VOLSER-specific. |
You can move tapes from one tape library category to another by using the ZTPLF MOVE command. Once a tape is added to a tape library category, it remains in that tape library category until you move it to a new tape library category, enter the ZTMNT command to mount the tape, or unload the tape. When the last two conditions occur, the tape is automatically removed from its current tape library category and added to the default tape library category.
Without tape library categories, you need to specify the name of the tape that you want to load. By using tape library categories, you can simply specify the type of tape you want to load; for example, a scratch tape. In this case, the tape library dataserver loads the first available scratch tape.
Different host systems can share the same tape library categories. For example, the TPF system can share tape library categories with an MVS system.
To add a new tape to the tape library dataserver, put the tape in the input station. The library manager adds the tape to the X'FF00' (insert) tape library category.
To remove a tape from one tape library category and add it to a different tape library category, enter the ZTPLF MOVE command.
For example, to move the AL1234 tape from the X'FF00' (insert) tape
library category to the X'FFFF' (VOLSER-specific) tape library
category, enter:
ZTPLF MOVE DEV-041C VSN-AL1234 FROM-FF00 TO-FFFF
You can move a tape from one tape library category to another at any time. For example, if the purpose of a tape changes, it may be necessary to add the tape to a different tape library category.
A tape is automatically removed from its current tape library category and added to the default tape library category when you mount the tape by entering the ZTMNT command or when you unload the tape.
You can define your own tape library categories. For example, you can define a tape library category for scratch tapes. To do this, enter the ZTPLF RESERVE command to reserve a general use tape library category (X'0001'-X'FEFF'). You can use this tape library category for scratch tapes.
For example, to reserve a general use tape library category in the tape
library dataserver that is attached to the 041C tape device, enter:
ZTPLF RESERVE DEV-041C
A message is displayed to indicate which tape library category was reserved. You can enter the ZTPLF MOVE command to add tapes to this tape library category. Other host systems can use a tape library category that you reserved. For example, other host systems can add tapes to a reserved tape library category, load the tapes in a reserved tape library category, and unload the tapes in a reserved tape library category.
Use the ZTPLF RELEASE command to return the reserved tape library category to general use when you are finished with it.
If a job requires a particular type of tape, you can use the tape library dataserver to add these tapes to the appropriate tape library category and then automatically load the necessary tapes.
To automatically load only one tape from a tape library category, enter the ZTPLF LOAD command.
For example, to automatically load the first available scratch tape from
the tape library dataserver that is attached to the 041C tape device,
enter:
ZTPLF LOAD DEV-041C CAT-1A00
You can also continuously load all the tapes in a tape library category one after the other by entering the ZTPLF FILL command.
For example, to continuously load all the scratch tapes one after the other
to the 041C tape device, enter:
ZTPLF FILL DEV-041C CAT-1A00
After the first tape in the tape library category is rewound and unloaded, the tape library dataserver automatically loads the next tape in the tape library category, and so on, until there are no more tapes in the 1A00 tape library category.
If the tape library dataserver is continuously loading the tapes in a tape library category, it preloads the tapes to the automatic cartridge loader (ACL) if the ACL is installed and a tape is currently loaded in the tape device. Otherwise, the tape library dataserver loads the tapes directly to the tape device when the tape device is available.
If you decide that you no longer want to use the tape that is loaded in a
tape device or the tape library category that is being continuously loaded to
a tape device, you can enter the ZTPLF UNLOAD command to automatically unload
the tapes. For example, to automatically unload a single tape from the
041C tape device, enter:
ZTPLF UNLOAD DEV-041C
If, in this case, the entire tape library category was being continuously loaded to the 041C tape device, the tape library dataserver unloads the current tape from the tape device and then automatically loads the next tape in the tape library category.
As another example, to automatically unload the tape that is currently
loaded in the 041C tape device and also cancel the continuous load of the
other tapes in that tape library category, enter:
ZTPLF UNLOAD DEV-041C ALL
If the tape that is currently loaded in a tape device is mounted, enter the ZTOFF command to dismount the tape before you unload it.
To query the status of the tape library dataserver, enter the ZTPLF QUERY command. You can display the following information:
For example, to display the status of the AL1234 tape, including the name
of the tape library category to which that tape was added, enter:
ZTPLF QUERY DEV-041C VSN-AL1234
As another example, to display a list of the tapes that were added to the
X'1A00' tape library category, enter:
ZTPLF QUERY DEV-041C CAT-1A00
The tapes are displayed in the order that they were added to the tape library category. You can also display the list alphabetically or begin the list after a certain number of tapes.
When the TPF system detects a long or lost interrupt, it stops waiting and performs a tape switch or reports a permanent error to the application.
When the TPF system detects a stalled tape module queue with no pending interrupt, it performs a tape switch or reports a permanent error to the application. You can adjust the time-out value for the stalled tape module queue by using the ZCTKA command.
The default for the time-out value is 0, which indicates that the system does not check for a stalled module queue condition. Change this value only if you experience repeated system failures because of out-of-storage conditions and when dumps indicate that module queues for one or more tape devices are not active. Report this condition to your IBM representative.
When operating in a multiple database function (MDBF) or loosely coupled processor environment, consider the following: