ptx/SPDRIVERS V2.4.0 Release Notes: IBM 3590 High Performance Tape Subsystem


Appendix A
IBM 3590 High Performance Tape Subsystem

ptx/SPDRIVERS V2.x.x contains the tc device driver that is for use with Magstar tape drives internal to IBM 3590 High Performance Tape Subsystems that are using a 10-cartridge ACF. The tc tape driver is not supported for use with Magstar tape drives in IBM 3494 Tape Libraries.

This appendix provides information specific to connecting the IBM 3590 Tape Subsystem to a DYNIX/ptx host, cabling considerations, and important operational considerations when using this device with a DYNIX/ptx host. For information about the IBM 3590 Tape Subsystem, the Magstar tape drive, general hardware installation or configuration, or media handling and maintenance, refer to the vendor's documentation that is supplied with the IBM 3590 Tape Subsystem.


Hardware Configuration and Firmware Considerations

The following caveats apply to the connection of the IBM 3590 Tape Subsystem to a DYNIX/ptx host:


Cabling Considerations

Cable connections for the IBM 3590 Tape Subsystem are different from other tape devices used with DYNIX/ptx systems. Use the following guidelines:

Figure A-1 illustrates the cable connections between DYNIX/ptx hosts and IBM 3590 Tape Subsystems.



Figure A-1. Cable Connections between DYNIX/ptx Hosts and IBM 3590 Tape Subsystems


The required DYNIX/ptx cables and terminator are as follows:


Operational Considerations

This section describes the following operational considerations:


Operational Caveats

Operational caveats you should be familiar with before using the IBM 3590 Tape Subsystem with a DYNIX/ptx host are as follows:


Operating Modes Supported

The tc driver supports the following IBM 3590 Tape Subsystem operating modes:

Manual
Accumulate
Automatic
Random

These modes are described in the user's guide for the IBM 3590 Tape Subsystem. This IBM document includes detailed instructions for selecting and initiating each of these modes. However, the following paragraphs cover several points of emphasis for operation with a DYNIX/ptx system. Be sure you review this information before using the IBM 3590 Tape Subsystem on a DYNIX/ptx system.


Random Mode Operation

In Random mode, the Automated Cartridge Facility (ACF) stacker is intended to be operated as a closed subsystem. That is, it is not expected that tapes will be added to or removed from the subsystem. The following paragraphs detail important considerations for Random mode operation.


Random Mode Startup

Complete the following steps to begin Random mode operation:

  1. Load all but one of the desired tape cartridges into the ACF. The front of each cartridge must be flush with the front of the ACF. This is referred to as the Import position. (When the front of the cartridge extends beyond the front of the ACF, allowing the operator to grasp it, the cartridge is in the Export position.)


    ATTENTION

    At least one of the ACF cells must be left empty before Random mode startup. Otherwise, the cartridge in the tape drive will have no place to be stored when it is removed from the drive.

    The cartridge present in the drive during Random mode initiation will be assigned to the first empty slot found during startup, and will be placed in that slot upon subsequent removal from the drive during normal mt ranload operations.


  2. Load the final tape cartridge into the tape drive.

  3. Engage the ACF mechanical lock.

  4. Select Random mode operation via the Set ACF Mode front panel option.

  5. Reboot the host to begin DYNIX/ptx control of the IBM 3590 Tape Subsystem and to initialize Random mode for the ACF stacker.


Change, Insert, or Remove Tapes in Random Mode

You may occasionally need to add, remove, or change a tape in the IBM 3590 Tape Subsystem, for example, to replace a defective tape or to use the cleaning cartridge. However, changing the ACF contents can cause the tc driver to become confused about the contents of the ACF, leading to possible data loss or the inability to recover system configuration information without rebooting the DYNIX/ptx system.

To avoid these problems, follow these steps to add or remove a tape when operating the IBM 3590 Tape Subsystem in Random mode:

  1. Stop all ACF activity.

  2. Set the ACF mode to Manual. Note that an ACF error will be reported on the 3590's display whenever the mode changes from Random to Manual. This is because the ACF lock, which is only valid in Random mode, will be on in Manual mode. This error message will be removed when Random mode is reselected.

  3. Insert or remove the desired cartridges.


    ATTENTION

    Be sure to insert or remove any required cartridges using the Priority slot. When a cartridge is reinserted into the drive, it must be reinserted from the Priority slot, not from the ACF. Disturbing any cartridges in the ACF while the system is not in Random mode can cause the tc driver to become confused and possibly unable to recover without rebooting the DYNIX/ptx system. That is, the number of cartridges and the slots that contain them must be exactly the same before and after you insert or remove any cartridges.


  4. Reset the ACF mode to Random.


Random Mode and the mt Command

Do not use the mt command with the ejectmag, offline, or rewoffl commands in Random mode. If you use any of these commands, the IBM 3590 Tape Subsystem will mark the cartridge that was in the drive as unloaded, but will not physically remove the cartridge from the drive. This action prevents mt ranload from inserting a new cartridge.

If this situation accidentally occurs, do the following:

  1. Select Manual mode via the IBM 3590 Tape Subsystem front panel. This will cause the "unloaded " cartridge to be physically unloaded into the Priority slot. As noted earlier, this will also generate an ACF error message on the IBM 3590 Tape Subsystem's display; this error message will be removed when the mode is reset to Random.

  2. Push the cartridge back into the Import position.

  3. Select Start via the front panel to reload the cartridge.

  4. Use the Set ACF Mode on the front panel to reselect Random mode.

  5. Select Start on the front panel to initiate Random mode.


End Random Mode

To end Random mode operation:

  1. Release the ACF mechanical lock.

  2. Select the new mode using the Set ACF Mode option on the front panel.

  3. Reboot the DYNIX/ptx system.


ATTENTION

System reboot is not required for temporary mode changes (for example, from Random to Manual to Random) made for normal maintenance operations or operator interventions .



Manual Cleaning of the IBM 3590 Tape Subsystem

The IBM 3590 Tape Subsystem can notify software when the device needs cleaning. However, the tc driver does not support this functionality. Instead, site personnel must manually schedule tape cleaning. In general, the cleaning cartridge should be used as follows:

Failure to clean the IBM 3590 Tape Subsystem often enough can lead to interrupted tape movements when using Random mode. If the *CLEAN message appears, subsequent attempts to replace the current tape cartridge using the mt command will be aborted after the current tape has been logically, but not physically, removed from the drive. Manual intervention will be required to recover from this condition.

For example, suppose that the drive is allowed to become dirty and the *CLEAN message is displayed. You then attempt to use mt to move the tape in the drive back to its home slot, slot 4, and load a new tape from slot 6 into the drive. This operation will be aborted, leaving the tape from slot 4 logically ejected but physically still in the drive.

To recover from this condition, you must manually complete the aborted mt command by doing the following:

  1. Select Manual mode from the front panel of the IBM 3590 Tape Subsystem to physically remove the tape from the drive.

  2. Unlock the ACF.

  3. Place the removed tape into its home slot, in this example, slot 4.

  4. Load the cleaning tape, clean the drive, and remove the cleaning tape.

  5. Manually remove the tape that you wanted in the tape drive from its slot, in this example, slot 6, and load it into the tape drive.

  6. Lock the ACF.

  7. Use the front panel to reselect Random mode.

Failure to follow this recovery procedure may lead to loss of device configuration data and possible user data corruption or loss, and may require a reboot of the DYNIX/ptx system to reestablish proper system configuration data.