In the stand-alone (non-system managed environment), even though a mix (different models) of 3592 devices is supported under a control unit, IBM recommends that all 3592 devices under the same control unit be homogenous for easier separation and management.

In addition to this, in the system-managed tape library environment, all 3592 drives under the same control unit must have the same recording format capabilities and report under the same ERDS physical identifier (EPI). This ensures that all of the devices under the same control unit are homogeneous and that each device under the same control unit is capable of handling the request.

A tape configuration database (TCDB) with EFMT4 and EEFMT4 volume records can coexist with lower-level systems. No additional coexistence support is needed to support the new recording formats and the new media types. However, because the 3592 Model E07 is only downward read (and not write) compatible with the EFMT3 and EEFMT3 formats (on MEDIA5-MEDIA8), EFMT2 and EEFMT2 formats (on MEDIA5-MEDIA10), and EFMT1 format (on MEDIA5-MEDIA8), you must specify (as appropriate) the read-compatible special attribute indicator (in the tape configuration database) or use LABEL=(,,,IN) on the DD statement of JCL to enable the 3592 Model E07 drive to be considered eligible for recording technology and media type combinations discussed above.

The Device Services component prevents any device that has an unknown EPI from coming online. Therefore, if a TS1140 tape drive is attached to a system that does not have any of the TS1140 support installed, the device is not allowed on-line and the following existing message text is issued for message IEA435I:

'UNKNOWN DEVICE IN EMULATION MODE NOT BROUGHT ONLINE'

When the Device Services full function support APAR is installed without the enabling APAR, the Device Service Exit will recognize the device EPI, but because the enabling APAR that brings all of the software support in is not installed, the device will not come on-line and the following new message text will be issued for IEA435I:

'3592-4E DRIVE DETECTED BUT NOT ALL 3592-4E SUPPORT IS PRESENT'.

• For the TS1140 tape drive support, OAM object tape coexistence support is provided at z/OS V1R11 and above, through installation of the full support PTF without the device services enabling PTF.
• OAM coexistence support prevents lower-level systems from selecting volumes with ERDS Physical Identifier (EPI) values for object write requests that are not supported on that system.
• OAM object support has coexistence considerations when running in an OAMplex environment with at least one system with the full support installed and enabled and at least one system without the full support for the new devices installed and enabled. In this mixed support environment, it is possible for a retrieve request to be received for an object that resides on a tape cartridge volume written in the EFMT4 and EEFMT4 format by a system that does not have the TS1140 tape drive full support installed. Coexistence support is provided that allows OAM to attempt to locate an instance of OAM in the OAMplex where the full support is installed and enabled. If an instance of OAM is found where the request can be processed, the OAM on the system where the request originated will ship the retrieve request, if the object is not greater than 50 MB, to the target system using XCF messaging services.
• Once TS1140 tape drives devices are used in an OAMplex environment and objects are written to tape volumes with the new EPI value recorded, it is expected that any OAM on a system where the full support is installed and enabled is eligible for processing requests using that volume. Therefore, TS1140 tape drives devices must be available to all instances of OAM where the full support is installed.